++++=comment lines that were not in print version
*page=page number of original printed version (e.g., page 115=*115), so to
search for p. 115, search for *115.
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3-A. INTRODUCTION-------------------------------------------------------35
3-B. CONDITIONS WHEN PREDATOR CONTROL IS JUSTIFIABLE ECONOMICALLY OR
OTHERWISE------------------------------------------------------35
3-C. ARGUMENTS FOR CORMORANT HARASSMENT IN TILLAMOOK COUNTY-------------36
3-D. ARGUMENT AGAINST HARASSMENT: THE HARASSERS ARE PRIVATE CITIZENS----36
3-E. ARGUMENT AGAINST CORMORANT HARASSMENT: COMPENSATORY PREDATION------36
3-F. ARGUMENT AGAINST CORMORANT HARASSMENT: ALTERNATIVES----------------40
3-G. ARGUMENT AGAINST CORMORANT HARASSMENT: ECONOMIC COSTS--------------40
3-H. ARGUMENT AGAINST CORMORANT HARASSMENT: BIOLOGICAL COSTS------------41
3-I. ARGUMENT AGAINST CORMORANT HARASSMENT: AESTHETIC AND SOCIAL COST---45
3-J. CONCLUSION: CORMORANT HARASSMENT CURRENTLY DOES NOT SATISFY THE
CRITERIA FOR AN ANIMAL DAMAGE CONTROL PROGRAM------------------46
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The subject of predator control has been one of considerable controversy. In recent years, the consensus of expert opinion (including reports from Advisory Committees on Wildlife Management or Predator Control to the U.S. Dept. of Interior [Leopold et al. 1964, Cain et al. 1972], the manual on wildlife management techniques by the Wildlife Society [Hawthorne 1980], and the Maine Cormorant Study [1982]) is that predator control is only justifiable if its tangible benefits outweigh its negative impacts on other wildlife and its economic, social, and aesthetic costs (also see Berryman 1972, Hornocker 1972, Beasom 1974, Peek 1986:224-230).
If predator control of cormorants along the Oregon Coast is to have any tangible economic benefits, the number of adult salmon or steelhead caught by fishermen must increase as a result of cormorant control. The only research to determine if bird control increased the number of adult salmonids caught in fisheries has been for Atlantic salmon (Huntsman 1941, White 1939a, Elson 1962); none of these studies demonstrated that predator control of birds increased the catches of adult salmon by fishermen (Vladykov 1943:129, Lack 1966:289, Mills 1967:390-391, 1980; Draulans 1987).
Further, catches of Oregon salmon and steelhead have often been as high or higher since predators such as seals, sea lions, and cormorants were protected in 1972 than previously (section 2-E-2). This also indicates that predator control along the Oregon Coast may not affect fishermen's catches.
To determine if animal damage control is advisable requires that all criteria in the following Table 3.1 be satisfied. For example, there must be a proof of need because predator control programs have too often been initiated only on the basis of assumed benefits and unrealistic predator consumption estimates (e.g., Cain et al. 1972) rather than on a real proof of need. As a result, the economic or biological costs of some predator control programs have often been greater than the resulting benefits (e.g., Cain et al. 1972, Beasom 1974, Peek 1986:254-261, Duffy and Siegfried 1987).
Overall, predator control is often of limited benefit in increasing numbers of game animals, especially if not all predators are controlled (Cain et al. 1972, Alexander 1979, Peek 1986).
---------------------------------------------------------------------------TABLE 3.1. Summary of criteria for when animal damage control (including harassment) is justifiable. Criteria are derived from Berryman (1972), Hornocker (1972), Beasom (1974), Alexander (1979), Hawthorne (1980), SERC (1980), Maine Cormorant Study Committee (1982:10), and Peek (1986:254-261).
---------------------------------------------------------------------------
CRITERIA TO JUSTIFY ANIMAL DAMAGE CONTROL
++++ start of p. *36 in SOO 6 (S6b.htm) | Contents | Index | References
Proponents of cormorant harassment have no evidence for the economic benefits of cormorant harassment; instead, they have suggested that the potential costs of cormorant predation at Tillamook Bay are significant enough to warrant harassment (see section 2-F). Since their extrapolated estimates for the potential costs seem unrealistically high and are certainly debatable (section 2-F), their estimates do not provide conclusive evidence for a real need for harassment at Tillamook Bay in April-June, let alone for all Oregon coastal streams as proposed in the original House Bill 3185 (section 1-I-1) or to the Oregon Fish and Wildlife Commission (section 1-J).
Further, proponents have not provided evidence that the economic benefits of cormorant harassment would exceed the economic costs of actually doing the harassment (see section 3-G). Supporters have merely assumed that cormorant harassment would pass a cost-benefit test; such an assumption is not sufficient to warrant predator control such as harassment (Cain et al. 1972, Hawthorne 1980, Peek 1986).
Some advocates of harassment argue that it seems such a waste to release hatchery smolts if they are going to be all eaten by cormorants. However, recent salmon and steelhead catches have been good along the Oregon Coast (Figs. 2.1, 2.2, 2.3, 2.4, 2.5, and 2.6), so it is clear that cormorants or other predators are not eating all smolts.
Cormorant harassment in 1988 (section 1-F) was done by private citizens, and House Bill 3185 (section 1-I) also proposed that private citizens harass cormorants on Oregon public waters. But Hawthorne (1980) and others recommend that animal damage control be done only by professionals if it occurs on public lands or waters.
There are a wide variety of game birds and threatened, endangered, or sensitive animals that occur on these public waters that could be incidentally harmed by harassment (section 3-H). This is another reason to allow only professional biologists or professional animal damage control personnel do the harassment (Berryman 1972, Hawthorne 1980:412, SERC 1980).
Finally, only allowing professionals do cormorant harassment is also advisable because it may help reduce the anxiety of the general public, who are concerned about the welfare of nontarget animals.
The second criterion to justify an animal damage control program is that there be no compensatory predation (i.e., smolts not taken by the controlled predator are taken by noncontrolled predators)(Table 3.1).
Since there is a wide variety of known and possible fish and bird predators of smolts other than cormorants (Tables 3.2 and 3.3 at end of this section), smolts that cormorants would have eaten may simply be eaten by other fish and bird predators. Hatchery smolts are so naive and vulnerable that predators that would not normally take wild smolts will take hatchery smolts (Appendix II). Further, hatchery smolts only learn to be wary of predators by being exposed to them (e.g., Ginetz and Larkin 1976, Patten 1975, Wood and Hand 1985, Olla and Davis 1988, 1989), so they are vulnerable to the first predators they meet, whether that be in an estuary or after smolts arrive in the ocean.
Most concern over smolt predation in Oregon has been about Common Murres (Ward 1983, Bayer 1986, McNeil et al. in press) or cormorants (Erickson 1988b, McAllister 1988). However, fish predators of hatchery smolts have received little attention in Oregon, probably because they don't eat smolts as conspicuously as birds. Elsewhere, there have been ample studies that have found fish predation of salmonids to be significant with 20-25% of smolts estimated to have been eaten by fish predators (Gunnerod et al. 1988). In fact, in some areas, fish predators have been estimated to take several times more juvenile salmonids than birds (Vladykov 1943). Thus, more studies are needed to determine the extent of smolt predation by predatory fish in Oregon (e.g., see Appendix VII).
Although little research has been concerned with fish that eat smolts in Oregon, there has been enough to show that subadult and adult salmon, steelhead, and cutthroat trout can be very significant predators of juvenile coho and chinook (Tables 3.4 and 3.5). For example, Fresh et al. (1981:35) estimated that 33% of the diet of subadult steelhead collected in July 1979 in the Pacific Ocean near the mouth of the Columbia River were chinook smolts.
Although each salmon, steelhead, or cutthroat may only eat a few smolts at a time (Table 3.4), these salmonids are very numerous, so that the total number of smolts they eat may be very large. For example, in 1981, 4.29 million smolts may have been eaten by coho, chinook, and steelhead adults and/or subadults (Table 3.5). This estimate may be conservative because the number of smolts eaten by cutthroat trout was unknown and because it was assumed that salmon and steelhead ate smolts only once a year, but they may have done so on several days. If they did so on just three days in 1981, then nearly 13 million salmon smolts would have been eaten just by salmon and steelhead!
Since salmonids eat smolts, it is not surprising that salmon, steelhead, and cutthroat trout can be limiting the survival of salmon smolts, and subsequently diminishing the number of salmon that could be caught by fishermen. For example, Nickelson (1986:533) suggested that adult coho predation of coho smolts could be a significant factor in decreasing smolt survival.
Striped bass can also be significant predators of smolts. For example, Shapovalov (1936:262) reported that six stripers taken in Coos Bay had eaten an average of 15.3 young salmon and trout (range 10-22) that were 4-8.5 in (10.2-21.6 cm) long; most of the salmon smolts were downstream migrating coho. Thus, striped bass were found to have eaten nearly twice as many young salmonids on the average than cormorants collected by the ADC at Tillamook Bay (section 2-F-5). Since House Bill 3185 (section 1-I) and the proposal to the Oregon Fish and Wildlife Commission (section 1-J) applied to all Oregon coastal rivers, striped bass need to be considered a compensatory predator, even though their northernmost population along the Oregon Coast is the Siuslaw River (McGie and Mullen 1979).
++++ start of p. *37 in SOO 6 (S6b.htm) | Contents | Index | References
Catching and keeping smolts by Oregon sports fishermen is illegal (i.e., the possession limit is at least 8 in [20.3 cm] from late May through the end of October and at least 12 in [30.5 cm] the rest of the year along the coast [1988 and 1989 Oregon Sport Fishing Regulations]). Nevertheless, sports fishermen are also smolt predators (Table 3.2). For example, at Yaquina Bay, some fishermen have been observed catching and keeping smolts while "jigging for herring" (Bayer, pers. obs.) or catching smolts while using spinners to fish for adult salmon (Roy Lowe, USFWS Biologist, pers. comm.). Lowe noted that smolts caught on salmon spinners were so badly hooked that they were unlikely to survive after being released. The problem of fishermen catching smolts is not limited to Yaquina Bay, since Claveria (1988) also reported this on Oregon's Molalla River.
--------------------------------------------------------------------------TABLE 3.2. Marine or estuarine predators that occur in Oregon waters that have been observed to prey on juvenile coho or chinook. Species are listed alphabetically. Threatened, endangered, sensitive, or potentially sensitive bird species (ONHDB 1987) and salmonid predators of juvenile coho or chinook are asterisked (*) boldfaced.
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Known Predator Reference(s)
----------------------------------------------------------------------------------
INVERTEBRATE
crab, red rock Mills (1977)
FISH
bass, striped Shapovalov (1936), Morgan and Gerlach (1950),
Shapovalov and Taft (1954:257), Stevens (1966)
hake, Pacific Anonymous (1959)
lamprey, Pacific Roos et al. (1973)
lamprey, river Beamish (1980), Myers (1980:171),
Roos et al. (1973)
lingcod Anonymous (1959), Olla and Davis (1989)
pollock, walleye Hart (1973:229)
rockfish, black Pearcy (1988:71)
rockfish spp. Anonymous (1959)
*salmon, chinook Anonymous (1959), Burck (1965), Fresh et al.
(1981), McCabe et al. (1983)
*salmon, coho Angstrom and Reimers (1964), Fresh et al. (1981),
Stuart (1984), Stuart and Buckman (1985)
sculpin, buffalo Levings (1984), Macdonald et al. (1988)
*steelhead Fresh et al. (1981)
sturgeon, white Merrell (1961)
*trout, cutthroat Anonymous (1959), Brodeur et al. (1987a:9),
Hart (1973)
BIRD
Auklet, Rhinoceros Simenstad et al. (1979)
Cormorant, Brandt's Bayer (1986)
Cormorant, Double-crested ADC Study (section 1-D-2)
Cormorant, Pelagic Bayer (1986)
Duck, Harlequin Mace (1983:13)
Guillemot, Pigeon Bayer (1986)
Gull, Bonaparte's Levings (1984), Mace (1983)
Gull, Glaucous-winged Mace (1983)
Gull, Heerman's Roy Lowe (pers. obs.)
Gull, Ring-billed Roy Lowe (pers. obs.)
Gull, Western Bayer (1986)
Heron, Great Blue Myers (1980:172)
Kingfisher, Belted Bayer (pers. obs.)
Loon, Pacific Mace (1983)
Merganser, Common Wood (1987), Wood and Hand (1985)
Murre, Common Bayer (1986), Matthews (1983), Ward (1983)
Murrelet, Ancient Mace (1983)
*Murrelet, Marbled Mace (1983)
*Pelican, Brown Bayer (1986)
Scoter, Black Mace (1983:13)
Scoter, Surf Mace (1983:13)
Scoter, White-winged Mace (1983:13)
*Tern, Caspian Bayer (1986)
MAMMAL
fishermen * Claveria (1988), Bayer (pers. obs.),
R. Lowe (pers. obs.)
seal, harbor ** Graybill (1981:43)
* In Yaquina Estuary, Bayer observed some fishermen "jigging for herring"
and catching salmon smolts. Also at the Yaquina, Lowe saw fishermen
catching smolts on spinners that were designed to catch adult salmon.
** Graybill found salmon smolts to be a minor prey item of seals in
Coos Bay; Fiscus (1980) and Simenstad et al. (1982:355) knew of no
records of predation on juvenile salmonids by harbor seals or sea
lions.
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++++ start of p. *38 in SOO 6 (S6b.htm) | Contents | Index | References
------------------------------------------------------------------------------TABLE 3.3. Marine or estuarine predators that occur in Oregon waters that may be predators of inadequate to determine all predators of juvenile coho or chinook (also see Appendix VII). Species juvenile coho or chinook. These species feed on baitfishes (e.g., Pacific herring or northern anchovies), and thus may feed on juvenile hatchery-released coho or chinook, which can be similar in appearance and size to baitfish. Thus far, research after a hatchery release has been are listed in alphabetical order. Threatened, endangered, sensitive, or potentially sensitive bird species (ONHDB 1987) and possible salmonid predators of juvenile coho or chinook are asterisked (*). Some freshwater predators are listed in Appendix II-B.
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Possible Predator Reference
------------------------------------------------------------------------------
FISH
albacore Pinkas et al. (1971)
cod, Pacific Clausen (1981)
croaker, white Morejohn et al. (1978:74-75)
dogfish, spiny @ Mace (1983:54), Ketchen (1986:17)
flounder, starry Orcutt (1950)
mackerel, jack Grinols and Gill (1968)
sablefish Grinols and Gill (1968)
*salmon, chum Bakkala (1970)
sanddab, Pacific Morejohn et al. (1978:74-75)
sculpin, Pac. staghorn @ Simenstad et al. (1979:148), Mace (1983:54)
shark, blue Morejohn et al. (1978:74-75), Harvey (1979)
shark, soupfin Ripley (1946), Hart (1973:40)
shark, thresher Hart (1973:31)
sole, petrale Morejohn et al. (1978:74-75)
sole, sand B. S. Miller (1967)
BIRD
Egret, Great Schlorff (1978)
*Grebe, Horned Palmer (1962:79)
*Grebe, Red-necked Ainley and Sanger (1979:106)
Grebe, Western Ainley and Sanger (1979:106)
Kittiwake, Black-legged Simenstad et al. (1979:244)
*Loon, Common Ainley and Sanger (1979:106)
Loon, Red-throated Ainley and Sanger (1979:106)
Merganser, Red-breasted White (1939b), Simenstad et al. (1979:235)
Puffin, Tufted Ainley and Sanger (1979:103)
Shearwater, Short-tailed Ainley and Sanger (1979:107)
Shearwater, Sooty @@ Wiens and Scott (1975:447)
Tern, Arctic Simenstad et al. (1979:245)
Tern, Common Simenstad et al. (1979:244)
MAMMAL
dolphin, Pac. white-sided Mitchell (1975), Morejohn et al. (1978:74-75)
otter, river Toweill (1974), Alexander (1979)
porpoise, Dall's Norris and Prescott (1961), Morejohn (1979)
porpoise, harbor @@@ G. J. D. Smith and Gaskin (1974), Morejohn et
al. (1978:74-75)
seal, elephant Morejohn et al. (1978:74-75)
sea lion, California Morejohn et al. (1978:74-75)
sea lion, northern Mate (1981:450)
@ This species can become quite abundant near a release site (Mace
1983:54).
@@ Sooty Shearwaters are abundant off the Oregon Coast (Wiens and Scott
1975:441), and several million have been estimated off the Columbia
River.
@@@ Harbor porpoises are occasionally seen near or in Oregon estuaries
(Bayer 1985b) near the sites of salmon smolt releases.
++++ start of p. *39 in SOO 6 (S6b.htm) | Contents | Index | References
------------------------------------------------------------------------------TABLE 3.4. Predation of juvenile coho or chinook by subadult or adult salmonids. Note that prey listed as "salmon" below were probably juvenile chinook but may have also included juvenile coho. Predation was determined by stomach contents, which indicates recent predation, not daily or yearly predation. N=number of predators sampled for stomach contents, MAX=maximum number of juvenile salmon per predator.
---------------------------------------------------------------------------
Predators Number of
with coho or
coho or chinook/
chinook predator
Predator Prey N (%) Mean MAX Reference
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chinook salmon:
subadult chinook ? 10 0.1 ? Fresh et al. (1981)
adul chinook 2 ? 1.5 2 Burck (1965)
coho salmon:
subadult chinook ? 11 0.8 ? Fresh et al. (1981)
adult salmon 2 100 1.5 2 Angstrom & Reimers (1964)
adult chinook/salmon 6 100 ? 3 Angstrom & Reimers (1964)
adult coho 141 25 2.2 6 Stuart & Buckman (1985)
adult coho 61 8 1.2 2 Stuart & Buckman (1985)
adult coho 37 5 1.0 1 Stuart & Buckman (1985)
cutthroat trout:
adult chinook/salmon ? ? ? 3 Brodeur et al. (1987a:9)
steelhead:
subadult chinook ? 20 1.0 ? Fresh et al. (1981)
subadult steelhead ? ? ? 4 Shapovalov and Taft (1954)
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TABLE 3.5. Estimate of number of smolts eaten by salmonid predators (except cutthroat trout) in 1981 along the Oregon Coast. The number of smolts/predator is estimated from the average number of smolts found in stomachs of salmon and steelhead in Table 3.4. The number of adult salmon and steelhead in 1981 is estimated from ocean commercial and sport recreational catches off Oregon (McQueen et al. 1988), from coastal stream
catches (ODFW 1987), and from Columbia River estimated run sizes (PFMC
1988). The number of subadult salmon and steelhead in 1981 is estimated
from the catches for the previously mentioned fisheries in 1982 (i.e., 1981
subadults were all assumed to survive until being caught in 1982). These
estimates may underestimate the actual number of smolts eaten in 1981
because fish predators can eat and digest smolts more than once each day
(see Peterson et al. 1982) and fish predators may have eaten smolts on more
than one day. Further, these also may be underestimates because the number
of salmon or steelhead that died without being landed by fishermen, escaped
to spawn in coastal streams, or moved into waters off Washington or
California are unknown. Estimates of the number of cutthroat trout present
off Oregon were not available.
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Smolts/ No. of Predators Total Smolts
Predator Age-class Predator (millions) (millions)
---------------------------------------------------------------------------
Chinook subadult 0.1 0.84 0.08
" adult 1.5 0.68 1.02
Coho subadult 0.8 1.15 0.92
" adult 2.2 0.99 2.18
Cutthroat adult 3.0 ? ?
Steelhead subadult 1.0 0.09 0.09
SUM= 4.29 million smolts
++++ start of p. *40 in SOO 6 (S6b.htm) | Contents | Index | References
The fourth criterion for justifying animal damage control such as cormorant harassment is that there are no alternatives (Table 3.1). There are, however, several alternatives to cormorant harassment that may reduce smolt losses to all predators, not just cormorants (see Chap. 4). As recommended in the Maine Cormorant Study (1982:10), alternatives should be explored before control is implemented.
The fifth criterion for an animal damage control program is that the economic loss or impact caused by predators justifies the economic, biological, aesthetic, and social costs of conducting the damage control program (Table 3.1). There are no conclusive data to indicate that smolt losses justify the economic costs of cormorant harassment, which includes the expenses of doing and monitoring the harassment as well as possible economic losses to the coastal tourist industry.
Expenses include the cost of cracker shells or other shells to scare cormorants, transportation costs for harassers to patrol an estuary, liability insurance to cover the costs of accidental injury to harassers or bystanders on public lands and waters, and wages if harassment is done by government employees.
To do a fish-eating predator control program properly, the area to be protected needs to be patrolled frequently. This may not be too much of a problem if only a small area such as a pond or hatchery is patrolled, but when miles of a coastal stream or estuary are to be patrolled, the cost grows rapidly.
Control of fish-eating predators may be economically feasible in simple situations such as at fish hatcheries or if there are only 1-2 predators involved. At fish hatcheries, however, it has long been recognized that shooting or harassing bird predators is simply not an effective solution to bird predation; the solution is to screen and enclose ponds so that the predators can't get in (Lagler 1939, Pough 1940, 1941, 1949; Cottam and Uhler 1945, Morrison 1975, Randall 1975, Mott 1978, Hawthorne 1980, Salmon et al. 1986, Draulans 1987, Parkhurst et al. 1987).
Since killing or harassment of fish-eating birds at hatcheries is known to not work effectively and screening estuaries is not possible, it is questionable if harassment would be cost-effective along a stream or an estuary.
During cormorant harassment at Nehalem and Tillamook Bays in the spring of 1988, the fishing guides and fishermen that harassed cormorants were not monitored or supervised (section 1-F). Because harassment opponents were concerned that harassers would disturb or harm nontarget wildlife (see section 3-H), House Bill 3185 was amended to allow ODFW supervision of harassers (section 1-I-3), and the proposal to the Oregon Fish and Wildlife Commission also included a provision for ODFW supervision (section 1-J). The ODFW estimated that monitoring would cost about $8,000/river or estuary for 3.5 months (section 1-J).
It is unclear if harassment would actually result in any more salmon or steelhead (section 2-H), let alone result in an increase worth $8,000 or more per river or estuary.
Since cormorant harassment would occur in public waters of coastal streams and involve the shooting of firearms, harassment would be highly conspicuous to tourists.
Tourists come to the Oregon Coast for its aesthestic values and to get away from the noise and turmoil of their normal lives. Many may not appreciate harassment or its accompanying shooting; many may also worry for their personal or family's safety about being in the vicinity of harassers using shotguns or other firearms to shoot noise-making shells at cormorants (also see section 3-I-2). Accordingly, some tourists may leave areas where there is harassment, which could hurt local residents who depend on these tourists for their livelihood.
In fact, some residents of Nehalem Bay have expressed their fears that their businesses may be hurt by cormorant harassment. In early June 1988 at Nehalem Bay, a marina owner and also a motel owner/manager independently approached Roy Lowe (USFWS Biologist), who was in USFWS uniform, and complained that they thought that the 1988 harassment at Nehalem Bay was bad for their businesses because part of their clientele came to the Oregon Coast to enjoy wildlife and did not appreciate birds being harassed.
Presently, the economic loss from cormorant predation is unknown but is probably much less than cormorant harassment proponents have suggested (see section 2-F). These losses may be offset, in part, by some possible, but unproven, benefits that may result from cormorant predation. For example, cormorants may primarily prey on weakened, sick smolts that could spread disease or parasites to healthy smolts (Vladykov 1943:127, Mills 1967:387).
Second, by taking smolts that are most vulnerable and are also easily detectable by other predators, cormorants can make it more difficult for other predators to detect healthy smolts and prey on them.
Third, cormorants may also be eating fish besides salmonids that are competitors or predators of salmonids. Elsewhere, predator control has sometimes been found to increase numbers of other harmful animals that the predator normally ate (Vladykov 1943, Mills 1967:388, Campbell 1979).
Finally, newly released smolts are naive about predators. There is evidence that smolts learn from seeing others being eaten and subsequently become much less vulnerable to predation (e.g., Ginetz and Larkin 1976, Patten 1977, Wood and Hand 1985, Olla and Davis 1988, 1989). Thus, it is possible, but unproven, that the overall survival rate of smolts that are first exposed to cormorants in coastal streams and estuaries (which would make the survivors more wary) may be higher than if the smolts are not exposed to predators until they reach the ocean where there are lots of predators.
++++ start of p. *41 in SOO 6 (S6b.htm) | Contents | Index | References
A biological cost of cormorant harassment is that it can affect nontarget animals, including threatened, endangered, or sensitive species and game birds. Even if harassers shot cracker shells only at cormorants, other birds and animals will subsequently also be disturbed because animals avoid sites of shooting. For example, anyone that has observed duck hunting knows that after a shot, many birds, not just the one shot at, are disturbed and fly away.
Because 1988 harassment occurred in tidewater areas of estuaries (section 1-F) and is proposed to continue there, nontarget birds that use tidewater areas such as the threatened or endangered Bald Eagle, Peregrine Falcon, and Brown Pelican; game birds such as Brant, and other birds could be harassed from areas that they normally use.
The intentional or inadvertent disturbance of nontarget birds is harmful because it can result in birds spending more time flying (which is energetically demanding), birds feeding for shorter periods of time, or birds being forced to leave good feeding areas to feed at poor sites (Henry 1980, Henry and Springer 1981, Burger 1981, 1986, 1988; Kaiser and Fritzell 1984, Knight and Knight 1984, Stalmaster 1987:160-169). Since harassment of cormorants is proposed for April-June, the subsequent disturbance to nontarget species would be during their spring migration or nesting season.
Some nontarget bird taxa that would be adversely affected by the harassment of cormorants are listed below; threatened, endangered, and sensitive birds species are from ONHDB (1987). Note that emphasis is placed on birds at Nehalem and Tillamook Bays because that is where most interest for cormorant harassment has been. Netarts Bay is included because STEP volunteers have taken over the Whiskey Creek fish hatchery there, and some volunteers have already expressed a desire to control or harass birds at Netarts Bay.
Information about birds at other Oregon coastal sites is also included because harassment was requested for all coastal streams in the original House Bill 3185 (section 1-I-1) and in the proposal to the Oregon Fish and Wildlife Commission (section 1-J). Since few data exist for birds at Nehalem and Tillamook Bays, information about birds at other coastal estuaries is also helpful in elucidating which species may be affected by harassment at Nehalem and Tillamook Bays.
Most information about birds given below is for the April-June period, when harassment has usually been proposed, but incidental notes about bird presence throughout the rest of the year is also given because the period of harassment was not specified in the original House Bill 3185 (section 1-I-1) or in the proposal to the Oregon Fish and Wildlife Commission (section 1-J).
Bald Eagles are very susceptible to human disturbance, especially gunshots (Mathisen et al. 1977, Stalmaster and Newman 1978, Stalmaster 1983, 1987:160-169; Knight and Knight 1984). Since Oregon coastal streams and estuaries support only a small number of breeding Bald Eagles that apparently remain throughout the year (Isaacs et al. 1983, Bayer 1987), the intentional or unintentional disturbance of these eagles should be of concern. Disturbance in March-August would be particularly detrimental to eagles because this is when they are incubating eggs or have young in the nest (Isaacs et al. 1983).
Incidental observations indicate that Bald Eagles are present at Nehalem, Tillamook, and Netarts Bays (Table 3.6 in section 3-H-9), and Bald Eagles are regularly present during winter, at least at Tillamook Bay (Table 3.7).
Peregrines appear to be making a comeback in western Oregon, and many use coastal estuaries (Tables 3.6 and 3.7; Roy Lowe, USFWS Biologist, unpubl. data).
At least a few Tillamook fishermen view Brown Pelicans as a threat to smolts because they were discussed as "predators" at the 3 August 1988 Tillamook Anglers/ODFW "Town Hall" meeting in Tillamook (Tillamook Anglers 1988).
In former years, Brown Pelicans were rare along the Oregon Coast in May but not in recent years (Table 3.6, Bayer unpubl. data). Pelicans are regularly within Yaquina Estuary in June (Appendix V), where they reach their peak of abundance in September or October (Bayer 1983b, 1986). Some remain until mid-December (Bayer 1988).
COMMON LOON.--The Common Loon is a USFWS Sensitive Species (ONHDB 1987:9). At Yaquina Estuary, they commonly overwinter, their spring migration peak is in February or April, some are present in May and June, a few oversummer, and they increase in abundance in October (Appendix V, Bayer 1983b). Since the Common Loon is a diver like cormorants, they can be found in the same areas as cormorants.
HORNED GREBE.--The Horned Grebe is a proposed State Sensitive Species (ONHDB 1987:8). Horned Grebes are common at Yaquina Estuary from September through May with peak numbers in fall (October or November) or spring (February-April)(Appendix V, Bayer 1983b). They are a diving species that can be found in the same areas as cormorants.
RED-NECKED GREBE.--The Red-necked Grebe is a proposed State Sensitive Species (ONHDB 1987:8). It is a diver found in Oregon estuarine waters from about October through May (e.g., Bayer 1988) with cormorants.
MERLIN.--The Merlin is a proposed State Sensitive Species (ONHDB 1987:9). Since they often feed on shorebirds, they would be expected to be present during the spring shorebird migration peak in late April and early May and during fall shorebird migration (see section 3-H-7).
++++ start of p. *42 in SOO 6 (S6b.htm) | Contents | Index | References
BUFFLEHEAD.--The Bufflehead is a Species of Concern (ONHDB 1987:8) that can be commonly found from about mid-October through mid-May in Oregon estuaries (e.g., Appendix V, Bayer and Lowe 1988:12). In April, an average of 119-260 was found at Nehalem, Tillamook, or Netarts Bays (Table 3.8).
GREATER YELLOWLEGS.--The Greater Yellowlegs is a shorebird Species of Concern (ONHDB 1987:8). 80 were at Tillamook on 18 April 1987 (Table 3.6); if there had been more censuses, more would probably have been found.
MARBLED MURRELET.--The Marbled Murrelet is a proposed State Sensitive Species (ONHDB 1987:8). Since it is rare inside Yaquina Estuary (although it can be found just outside its mouth, Bayer 1986) and there are no data for its occurrence in Nehalem, Tillamook, and Netarts Bays; it is unclear if they would be affected by the harassment of cormorants.
CASPIAN TERN.--The Caspian Tern is a species for which more information is needed to determine if its status should be of special concern (ONHDDB 1987:12). At Yaquina Estuary, they are present in April-October, with peak numbers in July through August (Appendix V, Bayer 1984, 1988).
Because waterfowl are regularly hunted, shooting would probably disturb them. Waterfowl mainly use the Siuslaw and Yaquina estuaries from about September or October through April (Bayer 1983b, 1987; Bayer and Lowe 1988:13), which is typical of many Oregon estuaries (Roy Lowe, USFWS Biologist, unpubl. data). In April, substantial numbers of several waterfowl are still present at Nehalem, Tillamook, or Netarts Bays (Table 3.8).
If waterfowl are inadvertently harassed during spring migration, it may adversely affect their nesting success and, subsequently, the numbers available to hunters in the following fall. Harassment may also hurt the nesting success of Mallards (the only regularly nesting, native waterfowl in Oregon estuaries) or Canada Geese, which have been introduced and now nest at several sites along the Oregon central coast (e.g., Bayer and Lowe 1988:50).
Waterfowl would be vulnerable to disturbance in April at Nehalem Bay, Tillamook Bay, or Netarts Bay because substantial numbers of several species are still present then (Table 3.8). Unfortunately, there are no May or June censuses available for these Bays, but May and especially June numbers for most waterfowl would probably be low. For example, only a few Buffleheads (discussed in section 3-H-5) are present at Yaquina Estuary in early May, and none were present in June (Appendix V). But 200 scaup and 30 Black Scoters were at Tillamook Bay in late May 1975 (Table 3.6), so some waterfowl can linger.
BRANT.--Brant overwinter at Tillamook and Netarts Bays (Roy Lowe, USFWS Biologist, unpubl. data), and these Bays, along with Yaquina Estuary (Bayer 1983b), are the only sites along the Oregon Coast where they regularly winter in any numbers (Bayer and Krabbe 1984, Bayer and Lowe 1988).
Brant are particularly vulnerable to shooting and disturbance (Henry 1980, Henry and Springer 1981). Shooting, in fact, has been considered to be the major reason why Brant seldom now overwinter at Humboldt Bay or at any other site in California (Henry 1980:4). Because of all the disturbance to Brant in California, more now overwinter in Tillamook Bay, Netarts Bay, or Yaquina Estuary (Bayer 1983b, USFWS unpubl. data, Christmas Bird Counts for Tillamook Bay) than any location in California (Henry 1980). It would be unfortunate if cormorant harassment caused Brant to abandon their last three Oregon overwintering sites because deserted wintering sites do not appear to be used again (see Henry 1980).
If cormorant harassment occurred only in spring, migrating Brant could still be disturbed by shooting. For example, in April, there were still many Brant at Tillamook and Netarts Bays (Table 3.8).
Even if overwintering Brant are not affected, the spring migrating Brant would certainly be disturbed by the shooting of harassers. Brant are routinely present at Yaquina Estuary into May, and sometimes oversummer into June (Appendix V). They probably also oversummer at Tillamook and Netarts Bays, since even incidental observations indicate that Brant were found at Tillamook Bay in late May 1975 and 1984 (Table 3.6).
The spring migration peak of small ("peep") shorebirds occurs in late April-early May at Yaquina Estuary (Appendix VI), Coquille Estuary (Hodder and Graybill 1984:15), and other estuaries in Washington and California (Page et al. 1979, Herman and Bulger 1981, Widrig 1981:49, Kalinowski et al. 1982:109, Buchanan 1988). At Tillamook Bay, there have been few observations, but 5,000 Western Sandpipers were still present on 8 May 1976 (Table 3.6). Many "peeps" are also present at Oregon estuaries during fall migration and winter (Hodder and Graybill 1984, Bayer unpubl. data).
Many Whimbrels have been found at Nehalem and Tillamook Bays in May (Table 3.6). At Yaquina Estuary, their spring migration peak is in late April or early May (Appendix VI), and many oversummer through June (Appendix VI, Bayer 1984).
Censuses of shorebirds other than peeps and Whimbrels at Yaquina Estuary indicate that their numbers also peak during spring or fall migration (Bayer unpubl. data). At the Coquille Estuary, some also overwinter (Hodder and Graybill 1984). Sporadic observations of shorebirds other than peeps and Whimbrels indicate that they are commonly at Tillamook Bay in May (Table 3.6). At Yaquina Estuary, the abundance of these "other shorebirds" also peaks in late April or early May (Appendix VI).
Harassment of cormorants in April-June could also affect other waterbirds, especially nesting residents. For example, Great Blue Herons and Western Gulls nest at Oregon estuaries (Bayer and McMahon 1981, Bayer 1983a).
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---------------------------------------------------------------------------TABLE 3.6. Selected April-June bird records for Nehalem, Tillamook, and Netarts Bays from "American Birds" (AmB) and "Oregon Birds" (OB) and unpublished USFWS aerial observations of Bald Eagles and Peregrine Falcons. USFWS records were kindly provided by Roy Lowe, USFWS Biologist.
---------------------------------------------------------------------------
NEHALEM BAY
5-18-1974. 31 Whimbrels (1974 AmB 28:842).
2-4-1988. 2 adult Bald Eagles (USFWS).
-----------------------------------------------------------------------------
TILLAMOOK BAY
5-12-1974. 16 Whimbrels (1974 AmB 28:842).
5-24-1975. 5 Brant, 200 Greater Scaup, 30 Black Scoters (1975 AmB 29:847-
848).
5-8 to 5-15-1976. 40-70 Whimbrels (1976 AmB 30:880).
5-8-1976. 5000 Western Sandpipers (1976 AmB 30:880).
5-10-1976. 143 Red Knots (1976 AmB 30:880).
3-19-1979. 2 Bald Eagles (USFWS).
4-28-1979. 250 Semipalmated Plovers (1979 AmB 33:800).
late August 1980. 1 Peregrine Falcon (1980 OB 6:192).
1-17-1981. 1 Peregrine Falcon (1981 OB 7:71).
3-21-1981. 1 Peregrine Falcon (1981 OB 7:71).
5-10-1981. 15 Red Knots was "high count in Oregon" (1981 AmB 35:855).
1-9-1983. 1 adult Bald Eagle (USFWS).
5-7-1983. 23 Red Knots (1983 AmB 37:905).
5-9-1984. 200 Short-billed Dowitchers, several hundred Dunlin (1984 OB
10:89).
5-19-1984. 35 Brant (1984 OB 10:86).
5-19-1984. 2 Brown Pelicans (1984 AmB 38:949).
5-25-1984. 75 Red Knots (1984 OB 10:89).
4-14-1985. 80 Short-billed Dowitchers (1985 OB 11:176).
summer 1985. Peregrine Falcon in Tillamook area all summer (1986 OB
12:134).
1-6-1986. 2 adult Bald Eagles (USFWS).
2-6-1986. 1 immature Bald Eagle (USFWS).
3-3-1986. 2 immature Bald Eagles (USFWS).
4-3-1986. 1 immature and 1 adult Bald Eagle (USFWS).
4-30-1986. 1000 Least Sandpipers (1986 AmB 40:516).
4-30 to 5-14-1986. 200 Semipalmated Plovers (1986 AmB 40:515).
1-5-1987. 1 Peregrine Falcon (USFWS).
1-7-1987. 2 adult Bald Eagles (USFWS).
2-5-1987. 3 immature Bald Eagles (USFWS).
12-15-1987. 1 Peregrine Falcon and 1 adult Bald Eagle (USFWS).
12-19-1987. 2 Peregrine Falcons (1988 OB 14:287).
4-18-1987. 80 Greater Yellowlegs (1987 OB 13:449).
5-6-1987. 135 Whimbrels (1987 OB 13:449; 1987 AmB 41:479).
11-2-1987. 1 Peregrine Falcon (USFWS).
2-4-1988. 2 adult Bald Eagles (USFWS).
2-10-1988. 1 adult Bald Eagle (USFWS).
2-24-1988. 1 adult Bald Eagle (USFWS).
3-3-1988. 1 adult Bald Eagle (USFWS).
---------------------------------------------------------------------------
NETARTS BAY
5-9-1979. 49 Ruddy Turnstones (1979 AmB 33:800).
5-21-1984. 4 Brown Pelicans (1984 OB 10:84; 1984 AmB 38:949).
4-5-1985. 1 adult Bald Eagle (USFWS).
---------------------------------------------------------------------------
---------------------------------------------------------------------------
TABLE 3.7. Bald Eagles and Peregrine Falcons recorded during Tillamook Bay Christmas Bird Counts (CBC) in December. Data are compiled from "American Birds." FREQ=percentage of CBC's with a taxon present.
---------------------------------------------------------------------------
FREQ Number.....
Years (%) Mean Range
-------------------------------------------------------
Bald Eagle 1973-1979 7 86 3.1 0-6
1980-1986 7 86 2.9 0-4
Peregrine Falcon 1973-1979 7 86 2.1 0-4
1980-1986 7 100 2.6 1-4
---------------------------------------------------------------------------
++++ start of p. *44 in SOO 6 (S6b.htm) | Contents | Index | References
---------------------------------------------------------------------------TABLE 3.8. U.S. Fish and Wildlife Service (USFWS) aerial waterfowl censuses at Nehalem, Tillamook, or Netarts Bays in April. No censuses are available for May or June. See Bayer and Lowe (1988:2) for methods. Unpublished censuses kindly provided by Roy Lowe, USFWS Biologist. Taxa are listed alphabetically.
---------------------------------------------------------------------------
NEHALEM BAY April...................................
Year 1979 1982 1983 1985 1986 Max-
Day 4-19 4-19 4-7 4-5 4-3 Mean imum
------------------------------------------------------------
Brant 45 0 0 0 0 9 45
Bufflehead 150 112 188 53 210 143 210
Coot, American 200 50 0 0 5 51 200
Duck, Ruddy 30 0 0 0 0 6 30
Gadwall 0 0 0 0 2 1 2
goldeneye spp. 0 1 0 0 8 2 8
Goose, Canada 0 0 5 0 0 1 5
Mallard 0 2 4 65 26 19 65
merganser spp. 70 63 70 95 23 64 95
scaup spp. 0 45 45 0 20 22 45
scoter spp. 0 42 17 38 10 21 42
Shoveler, Northern 0 65 10 75 10 32 75
Teal, Green-winged 0 0 0 35 14 10 35
wigeon spp. 0 10 209 170 208 119 209
TOTAL 495 390 548 531 536 500 -
--------------------------------------------------------------
TILLAMOOK BAY April...................................
Year 1979 1982 1983 1985 1986 Max-
Day 4-19 4-19 4-7 4-5 4-3 Mean imum
------------------------------------------------------------
Brant 0 181 245 50 230 141 245
Bufflehead 40 142 113 20 280 119 280
Coot, American 150 0 0 0 5 31 150
Duck, Ring-necked 45 0 0 0 12 11 45
Gadwall 0 0 0 0 150 30 150
goldeneye spp. 0 20 0 0 4 5 20
Goose, Canada 0 0 6 1 5 2 6
Mallard 20 78 1 69 132 60 132
merganser spp. 50 37 56 178 31 70 178
Pintail, Northern 0 3 0 0 25 6 25
scaup spp. 145 32 145 5 217 109 217
scoter spp. 405 185 93 33 172 178 405
Shoveler, Northern 0 0 0 0 20 4 20
wigeon spp. 135 137 439 829 2772 862 2772
TOTAL 990 815 1098 1185 4055 1629 -
--------------------------------------------------------------
NETARTS BAY April...................................
Year 1979 1982 1983 1985 1986 Max-
Day 4-19 4-19 4-7 4-5 4-3 Mean imum
----------------------------------------------------------
Brant 1940 200 191 0 670 600 1940
Bufflehead 470 158 185 34 453 260 470
Duck, Ruddy 160 0 0 0 0 32 160
Duck, Wood 0 0 5 0 0 1 5
goldeneye spp. 0 2 0 0 8 2 8
Goose, Canada 0 0 0 0 4 1 4
Mallard 85 0 0 0 4 18 85
merganser spp. 135 2 29 244 69 96 244
Pintail, Northern 65 0 0 0 0 13 65
scaup spp. 95 60 25 0 200 76 200
scoter spp. 0 3 149 161 429 148 429
wigeon spp. 225 0 59 10 0 59 225
TOTAL 3175 425 643 449 1837 1306 -
---------------------------------------------------------------------------
++++ start of p. *45 in SOO 6 (S6b.htm) | Contents | Index | References
The fifth criterion to justify animal damage control is that the economic impact of a predator exceeds the aesthetic and social costs of conducting the program (Table 3.1). Cormorant harassment presents several aesthetic and social costs.
It simply would not be aesthetically pleasing for harassers to shoot noise-making shells with 12 gauge shotguns or other firearms at cormorants in coastal streams or estuaries.
The shooting of firearms and the explosion of noise-making shells used in harassing cormorants could also disturb local residents. For example, the use of such noise-making devices was objectionable to homeowners at a reservoir in California where gulls were being harassed (Amling 1980). If cormorant harassment is allowed, the tourist industry may also be hurt (see section 3-G-3).
Oregon estuaries are used by a wide variety of people for recreational uses such as clamming, fishing, crabbing, boating, and bird watching. The pleasure of their recreational experience would be disturbed by the shooting of firearms in the non-hunting season. After hearing such shooting, some people could also justifiably worry about the safety of their families and themselves because they may wonder if real ammunition is being used.
Since coastal streams and estuaries are public property, everyone should be able to enjoy them without worrying about their safety or being disturbed by the shooting of harassers.
Attitudes towards wildlife have undergone great change in recent times and will continue to change as wildlife nonconsumptive use (i.e., viewing wildlife without killing it) continues to expand. Now the number of Oregonians who enjoy watching wildlife is greater than the total number of fishermen (Aney and Cowan 1975). The ODFW has recognized this change in their constituencies and anticipates that by the year 2000 that wildlife viewing will be as important as consumptive uses (Anonymous 1987d).
Since salmon and steelhead smolts after release are a public resource that occurs in public waters, the wishes of all the public of Oregon should be taken into consideration when debating the advisability of cormorant harassment.
Harassing cormorants because they sometimes eat hatchery smolts is inconsistent because game fish such as salmon, steelhead, and cutthroat trout also eat smolts (section 3-E), but they are not controlled. For example, striped bass have been found to eat nearly twice as many salmon and trout on the average than cormorants (section 3-E), and striped bass also eat steelhead smolts (Monroe 1989). Yet, striped bass are managed as a sport fishery (Monroe 1989), not as a "predator."
A decision to allow cormorant harassment because they are a "predator" is also inconsistent and arbitary because salmon themselves are significant predators of Dungeness crabs and commercially important fish (Table 3.9 at end of this section).
In fact, there is evidence that the California Dungeness crab fishery has been hurt by Oregon hatchery releases of coho (Reilly 1983, Thomas 1985). This is plausible because one adult coho caught off Oregon had eaten 809 Dungeness crab larvae, and 97% of coho collected in June off Oregon had eaten these crab larvae (Anonymous 1949). Further, Heg and Hyning (1951) found that coho off Oregon ate Dungeness crab larvae from June through September, with larvae forming an average of 24% of the September coho diet. Consumption of Dungeness crab larvae is not limited to adult coho because these larvae are also eaten by juvenile coho and chinook (Peterson et al. 1982) and adult chinook (Table 3.9).
If an analysis similar to Erickson (1988b) is calculated for the cost of coho salmon predation of crabs, the cost is great. For example, if each of the 0.99 million adult coho caught in Oregon in 1981 (Table 3.5) ate 809 Dungeness crab larvae for just 10 days in 1981, coho would have eaten 8.0 billion Dungeness crab larvae. If just 0.1% of those survived and were sold for $1.83 each (i.e., the 1986 price on landing for Oregon commercial crabbers averaged $1.41/lb [Lukas and Carter 1988]; and each crab weighed an average of about 1.3 lbs according to retail store advertisements in 1988), the value of Dungeness crabs eaten by adult coho in 1981 alone could have been about 15 million dollars!
Of course, this analysis has the same problems as Erickson's (1988b) figures and assumptions (see section 2-F), but it does demonstrate that coho predation has the potential for being costly. Therefore, if cormorants are to be harassed because they are a "predator," why not initiate predator control programs for salmon, steelhead, cutthroat trout, and striped bass because they are also significant predators (section 3-E)? Elsewhere, the significance of coho predation has been recognized, and, in one lake in British Columbia, coho salmon were killed because of their heavy predation on other salmon (Foerster and Ricker 1941).
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---------------------------------------------------------------------------TABLE 3.9. Chinook and coho salmon predation on some important fish or invertebrates caught in other Oregon fisheries.
---------------------------------------------------------------------------
Commercially
Predator Valuable Prey Reference(s)
---------------------------------------------------------------------------
chinook Dungeness crab Heg and Hyning (1951), Reilly (1983),
Brodeur et al. (1987a)
flatfishes Brodeur et al. (1987a)
Pacific herring Heg and Hyning (1951), Fresh et al. (1981),
Brodeur et al. (1987a)
lingcod Merkel (1957)
rockfish spp. Heg and Hyning (1951), Fresh et al. (1981),
Brodeur et al. (1987a)
salmon Table 3.2
squid Brodeur et al. (1987a)
coho Dungeness crab Anonymous (1949), Heg and Hyning (1951),
Reilly (1983), Brodeur et al.
(1987a, b), Thomas (1985)
Pacific herring Heg and Hyning (1951), Reimers (1964),
Brodeur et al. (1987a, b)
flatfishes Heg and Hyning (1951), Brodeur et al. (1987a)
rockfish spp. Heg and Hyning (1951), Reimers (1964),
Brodeur et al. (1987a)
salmon Table 3.2
squid Morejohn et al. (1978)
---------------------------------------------------------------------------
Permitting harassment would give a signal to some people that if cormorants are considered a predator significant enough to be legally harassed, they "deserve" to be also illegally harassed or shot. As it is, many cormorants may already be shot because some Oregon fishermen may believe, as do fishermen in Maine, that illegal shooting of cormorants is a fishermen's prerogative (Maine Cormorant Study Committee 1982:7). Such illegal shooting does occur in Tillamook County because Jo Walin (pers. comm) in mid-April 1989 found a dead cormorant on a beach just north of Nehalem Bay that had been shot.
Some people could also use the legalization of cormorant harassment to justify illegally harassing or killing other fish-eating birds or raptors because they are also "predators." This would be unfortunate because illegal shooting of nongame wildlife is already a significant problem in Oregon (Eltzroth 1986, Eltzroth letter dated 17 October 1988). In fact, the "protection" supposedly given to many nongame animals in Oregon as well as nationwide is inadequate because animals such as Great Blue Herons (Bayer 1981), eagles, hawks, and owls (Eltzroth 1986, Eltzroth letter dated 17 October 1988; Soucy 1988); and seals and sea lions (Stroud and Roffe 1979) either are often illegally shot or survive much better at National Wildlife Refuges where they are better protected.
Criteria that should be met to justify an animal damage control program are given in Table 3.1. Although proponents argue that harassment is justified, there is no substantial evidence that the need for cormorant harassment currently satisfies any of the criteria for animal damage control at Tillamook Bay during spring smolt releases, let alone for all Oregon coastal streams throughout the year as requested in the original House Bill 3185 (section 1-I-1) or in the proposal to the Oregon Fish and Wildlife Commission (section 1-J).
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***************************************************************************
*************************************************************************** 4-A. INTRODUCTION------------------------------------------------------47 4-B. ALTERNATIVES TO REDUCE PREDATION THAT ARE CURRENTLY PROMISING-----47 4-C. ALTERNATIVES TO REDUCE PREDATION THAT ARE NOT CURRENTLY PROMISING-51 ***************************************************************************
Animal damage control is necessary if there are no alternatives to control (Table 3.1). For example, when Double-crested Cormorants appeared to be a problem with trout releases at Crane Prairie Reservoir in Deschutes County, Oregon, the ODFW chose not to control cormorants but to reduce the problem by doing releases at night and by releasing trout all around the Reservoir, not at just one site (Anderson and Gates 1983, Fies 1984, Shotwell 1984, 1989).
There are a number of alternatives to cormorant harassment that could reduce predation by all smolt predators, not just cormorants, along the Oregon Coast. These alternatives may reduce predation by decreasing the detectability of smolts, increasing the wariness of smolts, or improving the ability of smolts to escape or avoid predators. These alternatives are examined throughout the rest of this Chapter.
Smolts are stressed during a release by being forced down a tube or out of a pond. Such stress (Sylvester 1972, Coutant 1973, Macdonald et al. 1988, Sigismondi and Weber 1988, Olla and Davis 1989) can increase their Stage I mortality (Appendix II) by making them more vulnerable to predation shortly after a release. Unpublished research indicates that smolts can behaviorally recover from the actual stress of release within about three hours (Michael Davis, Hatfield Marine Science Center, Newport; unpubl. data).
Besides the actual stress of release, another short-term stress suffered by some smolts is adapting to salt water. Smolts reared at ODFW hatcheries have lived only in freshwater, so when they reach estuaries they may take about 100 hours to acclimate (Harry Wagner, ODFW, oral testimony at 20 April 1989 Oregon House Agriculture, Forestry and Natural Resources Work Session on House Bill 3185). During this time, ODFW smolts act "sick" and have an impaired ability to avoid predators (Wagner, ibid.). In contrast, private aquaculture facilities in Oregon hold their smolts for a week or more in estuarine water; these smolts have thus had a chance to adjust to variable salinities before they are released.
If smolts are kept in predator-proof net pens until they have recovered from the stress of release or the stress of adapting to salt water, smolts may have a much better chance to evade predators. For ODFW releases, this may require trucking smolts from a freshwater hatchery to net pens in estuaries where smolts may be held for about 100 hours. For private aquaculture facilities, holding smolts in net pens may only be useful for about three hours.
The logistics of trucking and holding smolts in net pens from which smolts can be easily released have yet to be worked out. There will undoubtedly be some smolt mortality associated with these procedures, but this mortality may be offset by lower predation of smolts. The increased handling mortality may also be reduced as techniques are more fully developed.
If most predation occurs in or at the mouth of estuaries, then barging smolts offshore might help reduce predation and increase smolt survival.
OREGON BARGING RESULTS.--So far, barging off the Oregon Coast has had mixed results with barged coho smolts often having lower adult returns than nonbarged coho (Table 4.1 at end of this section, Gowan 1988, Pearcy 1988, McNeil et al. in press). These results may be because the techniques of barging off Oregon have not yet been perfected (Gowan 1988, McNeil et al. in press) or because there are more smolt predators in the Pacific Ocean than in estuaries (e.g., Macdonald et al. 1988).
The relative failure of barging smolts off Oregon may not be because of technique. ODFW barging studies have been with coho smolts transported in tanks with recirculating seawater on a boat (Anonymous 1984b, Steve L. Johnson, ODFW Biologist, pers. comm.). In Norway, Gunnerod et al. (1988) similarly transported Atlantic salmon smolts in tanks, but the Norwegian barging results showed barging to be helpful, while returns for ODFW barged coho were poorer than for nonbarged fish (Table 4.1).
Perhaps this geographic difference is because there are many more predators offshore of Oregon than offshore of Norway, so that any benefits of Oregon barging is negated. Since barging does not improve a smolt's wariness of predators nor increase it's ability to escape a predator, barged smolts would still be very vulnerable to marine predators. Further, after barging, smolts may move inshore where they may be vulnerable to the same predators as they would have been without barging.
One factor that may have been overlooked in the inconsistent success of Oregon private aquaculture barging studies (Gowan 1988, Pearcy 1988, McNeil et al. in press) is the inclusion of many small fish that are not truly smolted (i.e., the process whereby a young salmon or steelhead becomes physiologically able to live in salt water). While many undersized or nonsmolted fish released by private aquaculture into estuaries can remain in estuaries or go upstream into freshwater (i.e., "wrong-way smolts," Jonasson 1983, Nicholas and Herring 1983) until they are ready for life in salt water, these fish would have no place to find freshwater if they are barged offshore.
Since 20-40% of some private aquaculture smolts that have been released into estuaries were below the critical size for survival (Parker and Stohr 1983) and size as well as "smoltification" is important in determining smolt survival (Folmar and Dickhoff 1980, 1981; Bilton et al. 1982, S. L. Johnson 1982, Mahnken et al. 1982, 1984; Gowan and McNeil 1984, Zaugg et al. 1985, Gowan 1988, Ward and Slaney 1988), these undersized fish may need to be culled, if barging is to be of any consistent benefit.
++++ start of p. *48 in SOO 6 (S6b.htm) | Contents | Index | References
UPWELLING.--Barging has been hypothesized to improve smolt survival most in years with poor upwelling (Pearcy 1988). Pearcy (1988) based his hypothesis on data that only 40% of barged coho groups by an Oregon private salmon company had much better returns than nonbarged fish in two years of poor upwelling off the Oregon Coast.
Unfortunately, the data used by Pearcy (1988) were for barging studies whose techniques differed among years (McNeil et al. in press). Thus, it is not clear if barging technique or poor upwelling was responsible for the better returns. McNeil et al. (in press) present follow-up barging data to that presented by Pearcy (1988) but do not indicate what effect, if any, the amount of upwelling had on barging success.
Contra Pearcy's (1988) hypothesis, the results of ODFW barging studies, which used the same methods each year, indicates that the strength of upwelling may have little effect on the returns of barged fish (Table 4.1). In the two years of the ODFW's study with weak upwelling, the return of the best barged group of smolts was only 71-81% of the return for nonbarged fish released within the Columbia River; in the year with moderate upwelling, the return for the best barged group was, similarly, 74% of the nonbarged group (calculated from Table 4.1).
STRAYING.--Besides not always improving adult returns and the increased cost, another problem with barging is that straying by adult salmon (i.e., adults that do not return to their natal release site or hatchery) increases with barging (Johnson et al. 1985, Solazzi and Johnson 1986, Solazzi et al. 1987b, Gunnerod et al. 1988, Jacobs 1988, McNeil et al. in press). For example, the 1985 barging of smolts offshore of Newport by a private aquaculture company approximately doubled the amount of coho straying (Jacobs 1988:22). As a result of straying, more hatchery adult fish could interbreed with wild fish, which can hurt wild fish stocks (Appendix VIII).
---------------------------------------------------------------------------TABLE 4.1. Contribution to ocean and Columbia River fisheries by ODFW barged coho salmon smolts. Coho smolts were released in the Columbia River Estuary at Tongue Point, in the Pacific Ocean 10 mi (16 km) offshore in the Columbia River plume, 10-12 mi (16-19 km) offshore and 12-15 mi (19-24 km) north of the Columbia River plume, and 24 mi (39 km) offshore (beyond the Columbia River plume). Offshore releases were made from closed system tanks on a boat (Anonymous 1984b). 1983 release data are from Johnson et al. (1985), 1984 data are from Solazzi and Johnson (1986), and 1985 data are from Solazzi et al. (1987a). The strength of upwelling is from Pearcy (1988:70).
---------------------------------------------------------------------------
Percentage of Release Caught by
Fisheries for Smolts Released at.....
Smolt Offshore in Pacific......
Size Columbia 10 mi 10-12 mi 24 mi
at River at W & W & 12-15 W &
Year Dates Re- Strength Tongue in mi N of past
of Re- of lease of Point plume plume plume
lease Release (g) Upwelling (%) (%) (%) (%)
---------------------------------------------------------------------------
1983 June 2-9 33-34* weak 0.35 0.23 0.25 0.19
1984 May 25-31 36-38 weak 1.54 1.24 0.72 0.56
1985 May 24-31 32-33 moderate 10.57 5.47 7.85 4.36
*At Tongue Point in 1983, the average size at release was only 24 g.
---------------------------------------------------------------------------
++++ start of p. *49 in SOO 6 (S6b.htm) | Contents | Index | References
It appears that hatcheries often release fish when an average length or weight criterion is reached. Fish smaller than average, if they are below the critical size for survival (see Mahnken et al. 1982, Parker and Stohr 1983), may not survive because they are not yet ready for salt water.
This problem does not appear to apply to recent ODFW smolts; for example, calculations of length frequencies of samples of 200 or more coho smolts released at Trask Hatchery or Trask Pond on 8 April, 15 April, or 1 May 1988 indicated that 33%, 1%, and 0% of the smolts, respectively, were below Mahnken et al.'s (1982) critical size for survival of about 13.5 cm on 26 April 1978 (T. E. Cummings, ODFW Fish Propagation, letter dated 3 March 1989). The 33% estimated for the 8 April 1989 release is probably an overestimate because the critical size decreases earlier in the season (Mahnken et al. 1982, Parker and Stohr 1983), and Mahnken et al. (1982) did not give a critical size for earlier than April 26.
Further, the average size of coho smolts released in 1981 at the ODFW's Big Creek Hatchery near the Columbia River was not significantly different from the average for returning adults (Mathews and Ishida 1989), so most smolts that were released were large enough to survive.
In contrast to the relatively large ODFW smolts, 20-40% of smolts in some releases by the Newport private aquaculture facility were estimated to be less than the critical size for survival (Parker and Stohr 1983). Wilson (1986), according to Mathews and Ishida (1989:1225), also found survival of smolts from this facility to be size dependent. Estimated sizes of smolts at release for coho adults returning to this private facility are also given in Nicholas et al. (1982:18).
At a Coos Bay private facility, the average size of smolts at release in 1982 was also significantly less than the average for returning adults (Mathews and Ishida 1989). Thus, many smolts released from this facility were also too small for maximal survival.
If there are many fish below the critical size for survival, overall smolt survival may be improved by culling out small fish. Culling may help because fish that are too small are less healthy, are less adaptable to salt water, and probably are less able to evade predators. Accordingly, undersized fish may be more likely to attract predators than larger smolts; once attracted, the predators may then also feed on larger smolts. Thus, sorting and culling out fish below the critical size for survival may reduce predation of larger smolts (see Washington 1982).
Additional research is required, however, to determine if culling would actually improve overall smolt survival rates because the stress induced with sorting and culling could cause some mortality among the larger smolts.
Presently, hatchery smolts are fed by sprinkling pellets on the water surface. This teaches smolts to eat pellet-like objects on the water surface that are unlike food items in the wild. Since some smolts have a difficult time adjusting to natural food (Appendix II-C-2), changes in hatchery practices may help fish forage better after release. If smolts can be taught to forage better and spend less time at the surface looking for pellets, they would also be less vulnerable to predators (Appendix II).
One technique that may help hatchery fish adjust would be to feed them live or dead food items that they would normally eat after release. Even if this was only done for the last day or so that fish were held in a hatchery, it may help them get used to the smell and shape of natural food.
A second way to improve the post-release feeding ability of hatchery smolts would be to develop a way of distributing food pellets underwater rather than broadcasting pellets on the water surface. Since smolts have been entrained to expect food on the surface, they jump at inappropriate objects like styrofoam and pine needles and in so doing they are more easily detected by predators (see Appendix II-C-2). Unfortunately, distributing food underwater may not be practical.
There has been much work done on improving the dietary quality of salmon smolt diet pellets (e.g., Gowan and McNeil 1984). Nevertheless, diets appear to have been mainly developed to improve survival and growth of fish in hatcheries. More research about diets is needed to determine if diets can be improved to enhance smolt survival after they are released.
Oregon estuaries and coastal streams formerly had lots of woody debris that provided cover to migrating smolts (Benner and Sedell in press). This cover could be important in protecting smolts from predators, especially while smolts are adjusting to their new environment (e.g., Maser et al. 1988, McMahon and Holtby 1989, McMahon and Hartman in press).
Since marina docks are currently about the only cover for smolts left in Oregon estuaries, the attraction of smolts to docks (section 4-B-8) may indicate a normal response by smolts to use the only available cover.
The problem with trying to increase the amount of cover in Oregon estuaries to possibly enhance smolt survival is that such cover would impede boat navigation. Debris that could be used by smolts would have to be available during all tide stages, so it must be located in subtidal channels of estuaries, which are also heavily used by commercial shipping, commercial fishermen, and recreational boaters. Such debris would probably be considered an impediment to navigation that would be removed by the U.S. Army Corps of Engineers or the U.S. Coast Guard.
If hatchery fish could be taught to be wary of predators before they are released, their losses to predatory fish and birds may be much reduced. Subsequently, many more could survive to adulthood and contribute to the fisheries.
TEACHING SMOLTS WITH LIVE PREDATORS.--It may be possible to train juvenile salmonids at hatcheries to be wary of predators with live predators. For example, juvenile hatchery coho that survived exposure to a lingcod in a tank were less vulnerable to lingcod predation than fish that were not exposed (Olla and Davis 1988, 1989). Further evidence of the importance of exposure to live predators is that juvenile salmonids that had been previously exposed to predators survived better than naive ones (Ginetz and Larkin 1976, Patten 1977, Wood and Hand 1985, Suboski and Templeton 1989).
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One way to train fish about predators would be to have a fish predator in a plexiglass tank separated from juvenile salmonids. Then the salmonids could see a predatory fish attacking them, but not be eaten (Olla and Davis 1988). This technique, however, may not be practical at a hatchery because it would be difficult to have a plexiglass tank containing predators within a production hatchery pond. Further, this technique may not help teach fish about bird predators, although if hatchery fish learn to become wary of one predator, they may also become more wary of all predators, including birds.
A second method of training juvenile salmonids would be to introduce a live predatory fish or bird into each hatchery pond shortly before the fish are released. The loss of a few fish to a single predator that could not eat many of the thousands of fish in a pond could be offset by making the surviving fish less vulnerable to predators after release. A problem with this method is that an introduced predatory fish would be difficult to retrieve until the time of release; a predatory bird, however, might be more retrievable because it could be tethered like cormorants used by fishermen in the Orient.
The major problem with both these methods is that they need to be actually used and developed in hatchery production ponds to see if they are practical and if they will indeed improve smolt survival (e.g., see Quinn 1988).
TEACHING SMOLTS WITH MODELS.--Models of fish predators, some electrified, have been used to improve the ability of salmon fry to avoid fish predation (Thompson 1966, Kanayama 1968). As fish get older or larger, though, models do not appear to be effective in teaching fish to avoid predators (Kanayama 1968, Fraser 1974). For example, Fraser (1974) observed young brook trout simply avoid an electrified model of a Common Loon by just moving aside; obviously, the young trout did not associate the model with being eaten, and after release, the survival of trained trout was no better than for untrained trout (Fraser 1974).
There may be an optimal time of day to release hatchery fish to reduce predation immediately after they are released (Fresh et al. 1982, Mace 1983, Gowan 1988). For example, at the private aquaculture site in Yaquina Estuary, smolts used to be only released at night because day-time releases of stressed and disoriented smolts almost immediately attracted a host of bird predators (Bayer, pers. obs.). In 1989, however, smolts at this site were sometimes released during daylight (Anonymous 1989c), perhaps because it is then logistically easier to release smolts.
At a private aquaculture facility in Coos Bay, it has been documented that adult returns for smolts released during daylight were greater than for those released at night (Gowan 1988). The reason for this is not clear and should be explored to determine the optimal time of day for releases.
Optimizing the time of day for release may not be as important in reducing predation of ODFW smolts. In contrast to private aquaculture smolts that spend their last week or so in salt water before release, ODFW fish are reared only in freshwater. Accordingly, when ODFW smolts are released, it may take them about 100 hours to adapt to salt water; during this time they are "sick" and vulnerable to predators (Harry Wagner, ODFW, oral testimony at 20 April 1989 Oregon House Agriculture, Forestry and Natural Resources Work Session on House Bill 3185). Nevertheless, if ODFW smolts are released at a time of day when they aren't exposed to predators for several hours, their overall survival may still be improved if they have a chance of at least recovering from the initial shock of release (section 4-B-1).
At the 28 November 1988 ODFW meeting in Portland to discuss the cormorant issue (section 1-G), it was mentioned that lights at a marina in lower Nehalem Bay attracted smolts at night. It was suggested that this attraction could make smolts more vulnerable to predation, but this is unproven. In fact, the docks may actually provide the only available cover to smolts to help them avoid predators (see section 4-B-5), so the presence of smolts under docks may improve rather than decrease smolt survival.
If research indicates that marina lights make smolts more vulnerable to predation, then, as suggested at the meeting by Sara Vickerman (Defenders of Wildlife representative), an obvious solution would be to do something about the marina's lights. For example, the lights (especially those that are unnecessary) could be turned off, or light receptacles could be changed so that light does not shine down into the water and attract fish.
As pointed out in section 3-E, fishermen are also smolt predators, although catching and keeping smolts by Oregon sports fishermen is illegal. Even if smolts are released after being caught, many probably die. Thus, smolt predation may also be enhanced by better educating fishermen about not catching hatchery smolts and by also better enforcing fishing laws to protect hatchery smolts.
The date of release can affect smolt survival or the number of fish caught by fishermen (Bilton et al. 1982, Parker and Stohr 1983, Martin and Wertheimer 1987, Gowan 1988, Irvine and Ward 1989, Mathews and Ishida 1989). However, it may not be practical to hold smolts until the optimal release time. Further, it may be difficult to predict the optimal time because it can change yearly or because it may only be determinable long after it has passed.
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The following methods have been tried but do not appear to improve smolt survival. They are listed here because it is important to know what has been tried and failed so that the same mistakes are not repeated. It is possible, however, that even some of these methods may be improved and could help reduce smolt predation.
Just releasing more hatchery smolts in an attempt to increase the numbers of returning adults has been tried and failed. For example, through most of the late 1970's and early 1980's, the number of coho smolts released was increasing, but the number of returning adult coho remained about the same or even decreased (e.g., Pearcy 1988).
One reason why increasing the number of coho smolts released has not increased the number of adults is that smolt survival may be density- dependent (i.e., smolt survival decreases as smolt density increases). However, the density-dependence of coho is controversial (McCarl and Rettig 1983, McGie 1984, Nickelson 1986, Pearcy 1988, Peterman 1989). The mechanisms for density-dependence could be predation of adults on young as suggested by Nickelson (1986)(also see section 3-E) or competition among juveniles for food (see Appendix II-C).
Finally, a speculative reason why increased smolt releases has not helped is that the carrying capacity of the ocean for hatchery fish may have been reached. Since hatchery fish are less genetically diverse than wild fish (Appendix VIII), the ocean carrying capacity for hatchery fish may be less than for wild fish (Parmenter and Bailey 1985). In the past, the diversity of life styles of wild fish may have allowed many more to co-exist than is possible with today's less diverse hatchery fish.
Hatchery smolts receive little exercise while in hatchery ponds, so after they are released they may not be able to easily avoid predators or to swim efficiently (Besner 1980, Besner and Smith 1983, Smith et al. 1983, 1985; Shchurov et al. 1986). So far, exercising juvenile salmonids at hatcheries has not been demonstrated to increase their survival after release (Evenson and Ewing 1984). This failure may be because exercise has no effect on smolt survival, because the techniques of exercising fish have not been developed sufficiently to get improved results, or because hatchery fish are genetically inferior to wild fish in swimming skills (Smith et al. 1985).
If alternate prey are provided predators when smolts are released, then predators may eat the alternate prey and leave the smolts alone (e.g., Lagler 1939, Salyer and Lagler 1940, White 1957, Barlow and Bock 1984, Draulans 1987). If this happens, the alternate prey would have "buffered" the smolts from predation.
In effect, such buffering may already have occurred inadvertently because 20-40% of smolts released by the Newport private aquaculture facility have sometimes been too small to survive (Parker and Stohr 1983). The small smolts may have buffered the predation of larger smolts because undersized smolts have lower survival, perhaps because they are more vulnerable to predators (Bilton et al. 1982, S. L. Johnson 1982, Mahnken et al. 1982, Gowan and McNeil 1984, Gowan 1988, Ward and Slaney 1988). Since current predation is considered a problem, providing buffer prey may not be useful in reducing predation of viable smolts.
One problem with waiting to release smolts until after predators have left is that hatcheries are limited in how long they can hold fish, and it is also expensive to hold smolts.
In British Columbia, fish were released after migratory birds that fed on juvenile salmonids had left (Mace 1983). In Oregon, this would not work because murres, cormorants, and gulls (i.e., the major bird predators) do not depart the Oregon Coast in April-June, which is when cormorant harassment has been proposed.
Since the Japanese release some of their salmon after fish predators have migrated away (Bilton et al. 1982), this may also work in Oregon. But first, there needs to be more research in Oregon about fish predators of salmon and steelhead smolts (e.g., see Appendix VII) to see if it is possible to time releases to avoid them.
One way of reducing stress to smolts during a release would be to let fish leave ponds when they feel like it (i.e., a volitional release, Washington 1982), instead of forcing them out. If smolts were less stressed, they may be better able to avoid predators (Appendix II-B). Another advantage of volitional releases is that perhaps only fish physiologically ready for release would leave. So far, however, research indicates that smolt survival has not been improved with volitional releases (Mace 1983, Evenson and Ewing 1984, Gowan and McNeil 1984, Ewing and Evenson 1986, Gowan 1988).
Densities of smolts in hatchery ponds are much higher than they would be in the wild, which could affect their behavior and physiology (e.g., Schreck et al. 1985, Patino et al. 1986). Accordingly, it has been suggested that decreasing pond densities may increase smolt survival after release. Returns of adults from ponds with reduced densities, however, have not been consistently greater than from ponds with high densities (e.g., Washington 1982, Fagerlund et al. 1983, Gowan and McNeil 1984).
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5-A. INTRODUCTION-------------------------------------------------------52
5-B. IF DONE, CORMORANT HARASSMENT SHOULD BE DONE BY PROFESSIONALS------52
5-C. IF DONE, CORMORANT HARASSMENT SHOULD BE LIMITED TO SPECIFIC TIMES
AND SITES------------------------------------------------------52
5-D. IF THERE IS CORMORANT HARASSMENT, THERE SHOULD BE BUFFER ZONES
TO PROTECT NONTARGET ANIMALS-----------------------------------53
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Although cormorant harassment in Tillamook County does not appear to be economically, biologically, aesthetically, or socially justifiable; it may prove to be politically expedient. If cormorant harassment is allowed, the guidelines in Table 5.1 should be considered in regulating harassment. These guidelines are explained in the following sections.
---------------------------------------------------------------------------TABLE 5.1. Guidelines for cormorant harassment in Oregon estuaries. These guidelines are based on Leopold et al. (1964), Berryman (1972), Cain et al. (1972), Hawthorne (1980), Knight and Knight (1984), Stalmaster (1987), and McGarigal (1989).
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1) Harassment should be done only by government biologists or personnel.
2) Harassment should be strictly limited to times when and sites
where smolts are vulnerable to predation.
3) Harassment should not disturb foraging or resting game birds or
threatened, endangered, or sensitive wildlife. This may require
harassment to be at least 0.3 mile (0.5 km) away from areas where
nontarget animals are known to forage or rest.
4) Harassment should not disturb nesting birds. This may require
harassment to be at least 0.5 mile (0.8 km) from nesting birds.
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As discussed in section 3-D, if cormorant control is deemed necessary, it is clear that it should be done by governmental biologists or animal damage control personnel, not by private citizens. One reason for the involvement of only professionals is that cormorant harassment would occur on public lands and waters and involves a public resource. A second reason is that threatened, endangered, and sensitive species as well as game birds could be harmed by cormorant harassment (section 3-H). Berryman (1972), Hawthorne (1980:412), and SERC (1980) indicate that only professionals should do animal damage control under these circumstances.
The major concern about private citizens killing or harassing predators on public property is that they may intentionally or inadvertently harm nontarget wildlife. Private citizens, especially those using exaggerated data and inflammatory rhetoric to justify harassment (e.g., section 2-F), are not going to be trusted by everyone to protect nontarget wildlife.
STEP (Salmon and Trout Enhancement Program) volunteers should also not be harassers because predator control is not within the scope of STEP (ODFW 1985b). Further, predator control should not be included as a STEP project because STEP volunteers are not closely enough supervised to be sure they don't exceed their authority (section 1-E). Since STEP volunteers include some individuals who appear unduly biased towards anything that they feel is a "predator," STEP volunteers would also not be trusted by the general public to protect nontarget animals if they conducted cormorant harassment.
If the political situation dictates that private citizens do harassment, private harassers must have a permit to do so. Permittees should not have any ODFW, USFWS, or NMFS (National Marine Fisheries Service) game or nongame violations because violators could be suspected of further violations. Further, private harassers should be carefully monitored by ODFW personnel to be sure that they don't exceed their authority and that nontarget wildlife are not harmed. Such monitoring should be random and unannounced with private harassers losing their permit if they disturb nontarget wildlife. Violators should also face prosecution for violations of state or federal laws. Further, the USFWS should be notified of any harassment of threatened or endangered species, and NMFS should be informed of any harassment of marine mammals.
Animal control should be limited to times when and places where damage can occur (Leopold et al. 1964, Cain et al. 1972, Hawthorne 1980). Thus, cormorant harassment should occur only when and where smolts are being caught by cormorants because harassment is costly and also annoys some people. Further, the chances of harming nontarget wildlife increases as the amount of harassment expands.
Cormorant harassment may be limited to the period of time when they are catching most smolts, which may be within two weeks after a release because smolts are then most vulnerable and naive (Appendix II). For example, Bayer (1986) found that numbers of fish-eating birds during the 1983 El Nino were greatest in the first three days after a hatchery release of smolts at Yaquina Estuary.
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Unfortunately, there has not been any research to determine how to avoid disturbing nontarget birds during harassment. Guidelines #3 and #4 in Table 5.1 give estimated distances within which harassment of cormorants should not be permitted. Since birds are more sensitive to gunshots (e.g., cracker shells shot with a shotgun) than some other forms of human disturbance, these distances may need to be extended to adequately protect nontarget animals.
To minimize the impact of cormorant harassment on threatened, endangered, or sensitive animals or game birds, cormorant harassment should not take place within at least 0.3 mile (0.5 km) of where these animals feed or rest.
This is important because nontarget animals may avoid areas of cormorant harassment and subsequently increase their energetic demands by flying or decrease their feeding efficiency by being driven from prime feeding areas to feed in marginal areas (section 3-H). Since cormorant harassment is proposed in April-June during the time of migration and nesting, unrestricted cormorant harassment could result in decreased nesting success for nontarget animals.
The size of the buffer zone for foraging or resting birds is based on the research of Knight and Knight (1984) in Washington, and McGarigal (1989:106) along the lower Columbia River in Oregon. To protect Bald Eagles at feeding areas, they recommended that boaters should be kept at least 0.25-0.28 mile (0.41-0.45 km) away from where eagles forage. Since Stalmaster and Newman (1978) found that Bald Eagles in Washington are easily disturbed by gunshots (which would be equivalent to the shooting of cracker shells by cormorant harassers), a restriction zone of 0.3 mile (0.5 km) may not be adequate to protect Bald Eagles or Brant (Henry 1980) that are also sensitive to gunshots.
Nontarget nesting birds should also be protected from cormorant harassment. Nesting species that could be adversely affected in Oregon estuaries include Bald Eagles, Mallards, Canada Geese (Bayer and Lowe 1988), and Great Blue Herons; all would be nesting throughout the April- June period suggested for cormorant harassment. The size of buffer zones to protect nesting birds has been most studied for Bald Eagles, but not allowing harassment within 0.5 mile (0.8 km) of nests may be adequate to protect other nesting species, too.
To protect nesting areas of Bald Eagles, Stalmaster (1987:166) indicated that a commonly used system involves territory zoning with both a primary and a secondary zone. In this system, no human activity is allowed within a primary zone of 0.06 mile (0.1 km) of the nest throughout the year. Human activity is also restricted in a secondary zone around alternate nests, perches, or roost trees during seasons when they are used by eagles. The shape and size of the secondary zone depends on the habits of the nesting pair and the amount of cover in the area; it can be as much as 0.6 mile (1 km) from the nest (Stalmaster 1987:166). Since Bald Eagles can use nest sites throughout the year in Oregon (Isaacs et al. 1983) and specifically along the Oregon Coast (Bayer, pers. obs.), this means that the secondary zone around eagle nests should also be protected from people harassing cormorants throughout the year.
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6-A. INTRODUCTION-------------------------------------------------------54
6-B. VARIABLE DEFINITIONS OF WILDLIFE AND CONSERVATION------------------54
6-C. EXAGGERATED CLAIMS CAN BE COUNTERPRODUCTIVE------------------------54
6-D. THE ODFW's PUBLIC RELATIONS COULD BE IMPROVED----------------------54
6-E. LEGISLATIVE DEBATE OF HOUSE BILL 3185 ABOUT CORMORANT HARASSMENT---55
6-F. SUCCESS OF HOUSE BILL 3185 IN OREGON HOUSE-------------------------58
6-G. FAILURE OF HOUSE BILL 3185 IN OREGON SENATE------------------------58
6-H. FAILURE OF BIOLOGICAL DATA TO PERSUADE LEGISLATORS: BIOLOGISTS
NEED TO BETTER COMMUNICATE WITH NONBIOLOGISTS------------------58
6-I. IS OREGON WILDLIFE OR WILDLIFE MANAGEMENT FOR SALE?----------------58
6-J. WHEN IS PREDATION BY A SMOLT PREDATOR SIGNIFICANT?-----------------59
6-K. CAN THERE EVER BE ENOUGH SALMON OR STEELHEAD?----------------------59
6-L. THE CORMORANT ISSUE WILL CONTINUE IN NORTH AMERICA-----------------59
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Trying to understand the cormorant/fisherman conflict is an educational as well as a philosophical experience. This conflict is not limited to Tillamook County in 1988-1989; it is an ancient conflict that will probably continue as long as there are fishermen and cormorants. In the following sections, various points that can be learned from this conflict are examined.
While working with this issue, I became increasingly aware that "wildlife" and "conservation" mean quite different things to different people. To some, "wildlife" only includes game or commercially important animals. "Conservation" of wildlife to these people means the enhancement of game or commercially important animals. For example, a fisherman or state fish and game department may consider clearing streams or lakes of "trash" fish as "conservation" of "wildlife," even though such "conservation" kills the nongame species of "trash" fish.
Because their focus is on game or commercially important animals, sportsmen and state fish and game departments often believe that money raised from licenses or fees on sportsmen and spent on game animals automatically benefits nongame animals (e.g., Gladson 1982, Hamilton 1984). This may often not be true, especially for nongame species whose needs either conflict with or are markedly different from the needs of game animals.
Keeping the diversity of definitions in mind is important in trying to communicate or understand an issue. Otherwise, people may not mean the same thing when they talk at each other.
"The squeaky wheel gets the grease"; so some harassment proponents may have felt the only way that they would be heard is if they exaggerated by claiming that cormorants were destroying salmon and steelhead runs. This strategy worked to a certain point, as the exaggerated claims and effective lobbying managed to get House Bill 3185 passed in the Oregon House by a vote of 56 to 4.
The problem with using exaggerated claims is that eventually they, and perhaps their promulgators, lose credibility. The day of reckoning came in the Oregon Senate, where proponents' claims were apparently more carefully scrutinized and were seen to be more rhetoric than substance. HB 3185 could not muster the votes to be even heard in a Senate Committee (section 1-I-5).
If proponents had relied more on facts and less on rhetoric, they may have been more effective in building support. If proponents had used only the actual, not the imagined, results of the ADC study (e.g., section 2-F-5) and showed their videos illustrating large numbers of cormorants at Tillamook and Nehalem Bays, they may have been more successful. As it was, the exaggerations and the unpolitic public relations of some proponents seemed to undermine the proponents' credibility about salmon management, to turn potential supporters into opponents, and to make some opponents committed to opposing the proponents' plans.
Salmonid management is a thankless, no-win chore. A Washington State salmon manager (Darwin in Wright 1981) had the following to say about his job:
"At the end of eight years, I realize what a thankless task it is to
try to preserve a great natural resource for a country. . . . In the
Senate Chamber in 1919, at a public hearing on the fisheries code,
which I prepared and which would have curtailed the fishing for both
mature and immature salmon, one of the spokesmen for one of the
fishermen's organizations declared that any person who would put
forward a proposal for curtailing fishing should be beheaded."
The situation remains the same today as 70 years ago, and it is nearly impossible to satisfy all fishing interests (see section 2-B). Thus, the ODFW is stuck with a no-win situation in managing salmon and steelhead (e.g., Gunsolus 1980).
While I sympathize with the ODFW's predicament and its public relation problems with salmonid management, I have also been dismayed by the ODFW's handling of the cormorant harassment issue. Instead of countering exaggerated claims by harassment proponents (e.g., smolts cost $1.25 each and salmon and steelhead fisheries are approaching ruin) with facts that the ODFW had, ODFW officials often seemed evasive or remained silent and in so doing gave credibility to the claims of harassment proponents.
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It appears that current ODFW policy is not to confront and debate such claims, no matter how unrealistic they may be. Evidently, the ODFW hopes that such issues will just go away, but the cormorant harassment issue is a clear example of an issue that hasn't and probably won't.
If the ODFW chooses not to respond to such claims in newspaper articles, it should at least try to hold public or "townhall" meetings in which such claims are countered (e.g., see Colvin et al. 1983). This issue may have been somewhat defused if there had been more of an effort by the ODFW to explain in public forums in the Tillamook area the complexity of the smolt predation problem.
To deal with the cormorant issue, it would also have helped if the ODFW had at least one biologist with expertise about fish-eating birds; presently, the ODFW has many fisheries biologists, but their knowledge and perspective about bird predators sometimes appears limited and one-sided.
For example, the ODFW's Harry Wagner (who has a fisheries background) told me after the April 20 House Agriculture, Forestry and Natural Resources Committee Work Session that some ODFW fisheries biologists trying to determine the reason for the decline of wild coho salmon in the Yaquina Basin had concluded, without any evidence, that bird predation must be the culprit. This frame of mind and conclusion may be expedient for fishery biologists such as Wagner because they would rather blame birds than consider that the long-term straying of private hatchery coho in the Yaquina (and nearby Basins) had hurt wild coho stocks (see Appendix VIII).
Whether it likes it or not, the ODFW needs to recognize that it is going to increasingly become more involved in public relations. The number of consumptive and nonconsumptive wildlife user groups is growing and diversifying; there are conflicts among some consumptive user groups (e.g., among salmon fishermen, see section 2-B) and between some consumptive and nonconsumptive user groups. In the future these conflicts will increase, not decrease, because wildlife resources cannot grow commensurately with population increases and subsequent habitat destruction.
Dealing with these conflicts is going to require improved ODFW public relations because conflicts may not be solvable by changing wildlife management practices. The ODFW needs to explore ways of actively dealing with public relations problems as they are first developing rather than waiting until they become blown out of proportion. Training should include dealing tactfully with citizens that disagree, sometimes vehemently, with ODFW policies (e.g., see Colvin et al. 1983). Such training is necessary because in controversies such as salmonid management it is impossible for the ODFW to satisfy all fishing interests, and salmonid fishermen appear to be particularly vociferous and adamant.
Although ODFW personnel at local offices may be able to handle most public relations issues, they can't be expected to deal with festering problems like the cormorant issue. Accordingly, ODFW administration needs to recognize this and be able and willing to send "reinforcements" to local areas. These "reinforcements" should be specially trained to actively address and explain issues such as the cormorant issue at public forums or in other meetings with reporters or the general public.
Although I have attempted to use reason and facts in discussing the cormorant harassment issue in this monograph, most of the debate about this issue in the Oregon Legislature involved politics and persuasiveness.
My impression of how House Bill 3185 was discussed in the Legislature is given in the following sections.
Currently, the Legislature meets every other year. In 1989, it met for 177 days and considered 3,020 bills. There is no way that a legislator can be knowledgeable about every bill, nor have the time to study each bill. Accordingly, legislators are open to the influence of lobbyists and political maneuvering on determining how to vote.
Because legislators can not keep up with all issues, their ignorance about some issues can sometimes show up during Committee hearings, work sessions, or floor debate. For example, during the House Agriculture, Forestry and Natural Resources Committee Hearing on April 13, a discussion began about shags (=cormorants) roosting in trees along the Rogue River in southwestern Oregon. One Committee member, Rep. Robert Shiprack (D- Beavercreek) laughed at this idea and argued that it was impossible for cormorants to roost in trees because cormorants had webbed feet, and thus could not grasp tree limbs with their feet (Shiprack 1989). Perhaps to avoid embarrassing Shiprack, no other Committee member that was present disputed Shiprack's assertion. Shiprack and perhaps other Committee members may not have been aware that Double-crested Cormorants routinely roost and nest in trees in central Oregon (Anderson and Gates 1983, Shotwell 1984, 1989) or can even perch on power lines (Bartholomew 1942).
During the 1989 Legislative session, the Spotted Owl/old-growth forest issue also flared up. Many legislators feared that if Spotted Owls became a federally threatened species with a subsequent curtailment of old-growth logging then there would be a great loss of jobs in the logging and lumber industries. Some legislators were so incensed about "environmentalists" and Spotted Owls that House Bill 3491 was introduced to put a $500 bounty on live-captured Spotted Owls; this Bill had wide support and was sponsored by 25 Representatives and 11 Senators. The Spotted Owl debate was acrimonious, and it is unclear if some of the rage about the Spotted Owl controversy (about which the Oregon Legislature could really do nothing because it was a federal matter) spilled over to the consideration and subsequent passage of HB 3185 in the Oregon House, a bill that irate Legislators could pass to get back at "environmentalists."
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Proponents of harassment were very effective in getting HB 3185 through the Oregon House. Perhaps much of the credit for this should go to Rep. Paul Hanneman (R-Tillamook), who was chief sponsor of this Bill. He evidently persuaded several other Oregon legislators from the Oregon Coast to be co-sponsors, so that it appeared as if the Bill had wide coastal support. Additional leverage to persuade other Representatives to favor the Bill was achieved by having Rep. Larry Sowa (D-Oregon City) from the Willamette Valley as an active co-sponsor. Since Hanneman and Sowa were influential members of the House Ways and Means Committee, any Representative sponsoring a bill needing funding could be open to persuasion by Hanneman and Sowa.
Another key player was Jason Boe, a paid lobbyist (Ota 1987). Boe was very familiar with how to get things done in the Oregon Legislature because he had been Senate President from 1973-1981 (McDonough 1980, Ota 1987).
Loren Parks also appeared to be effective in persuading Representatives to pass HB 3185. Parks spoke in favor of the Bill at the April 13 House Agriculture, Forestry and Natural Resources Committee Hearing. Parks is a successful businessman (see section 6-I); businessmen seem to have more clout in the Legislature than biologists.
Although many of his claims are debatable (sections 2-F and 2-H), Jim Erickson was also a capable supporter of HB 3185. At the April 13 House Hearing, Erickson presented his side of this issue convincingly and energetically; his self confidence may have won legislators to his side.
Even though HB 3185 was easily passed by the Committee and House, there was substantial, although perhaps ineffective, opposition to it. Each and every Representative was contacted or received at least once piece of mail opposing this Bill.
ODFW.--ODFW staff testified against HB 3185 at the April 13 House Hearing, but the only ODFW official (Harry Wagner) to speak at the April 20 Work Session of the House Agriculture, Forestry and Natural Resources Committee was very equivocal and seemed to speak as much in favor of HB 3185 as against it.
The ODFW may have not been able to oppose this Bill as much as they could have because the ODFW Biennial Budget had not yet been passed. Since Reps. Hanneman and Sowa of the House Ways and Means Committee were sponsors of HB 3185, ODFW administrators may have felt that if they strongly opposed this Bill that their Budget may have been hurt. Since the ODFW's Budget is up for debate each legislative session, the ODFW is then vulnerable to political decisions about wildlife that are not based on biological data or sound wildlife management.
The ODFW may also not have opposed HB 3185 as much as they could have because the ODFW appeared to be somewhat split about cormorant harassment. In dealing with various ODFW staff, it was my impression that some ODFW personnel (e.g., Kunkel in Hendrickson 1988a, Harry Wagner during April 20 House Committee Work Session [see 6-D-3]) actually favored cormorant harassment. I would expect ODFW harassment supporters to most likely be fisheries biologists or fish propagationists, while ODFW wildlife or nongame biologists are more apt to oppose harassment, especially if the need for harassment is based only on exaggerated evidence.
ENVIRONMENTAL GROUPS.--Although it might be supposed that many environmental groups would have been active in their opposition to House Bill 3185, most environmental groups seemed to shy away from this issue in the Legislature. For example, at the House Agriculture, Forestry and Natural Resources Committee Hearing on April 13, only five private citizens testified against the Bill. Only one of the five represented a large environmental group (Marc Liverman, a lobbyist representing the Portland Audubon Society); of the remaining four, one was from Tillamook County and three (including myself) were from Lincoln County. Further, the only written testimony submitted to this Committee for this Hearing from large environmental groups was from the Portland Audubon Society and from the Corvallis Audubon Society.
The lack of oral or written testimony at the April 13 hearing was not because environmental groups were unaware of House Bill 3185 or the April 13 Hearing. On 8 March 1989, I mailed informational flyers about HB 3185, and, on April 5, I mailed notices of the April 13 Hearing along with copies of my 37-page written testimony for the Hearing (see following subsection) to numerous representatives of environmental organizations including the Sierra Club, Oregon Environmental Council, Greenpeace, Oregon Natural Resources Council, each Oregon Audubon Chapter, Wildlife Defense NW, a few bird rehabilitators, and several other environmental groups.
The passage of HB 3185 by a vote of 56-4 in the House on May 1 is clear evidence that environmental groups did not get seriously involved in trying to defeat this Bill in the Oregon House. Large Oregon environmental organizations have their bases in the Portland, Salem, and Eugene metropolitan areas; which is also where most Representatives were from. In spite of having about 15 Representatives endorsed by the Oregon League of Conservation Voters from these areas, only four of them voted against HB 3185. Surely, if there had been some concerted effort by the large environmental groups, more Representatives would have opposed this Bill.
There are several reasons why many environmental groups may not have publicly opposed HB 3185 in the Oregon Legislature. Firstly, some groups may not have had the time or energy to get involved, or they may have been focusing their efforts on other issues; there are so many environmental issues it is not possible to be active in them all.
Some groups may have chosen not to become involved with this Bill because cormorants are not a "glamour" bird like Bald Eagles, Osprey, or Great Blue Herons. What these groups overlooked is that these birds could also be affected by cormorant harassment (section 3-H) or that some anglers would want to extend harassment to birds such as Great Blue Herons once cormorant harassment was allowed. Further, if HB 3185 passed, then some fishermen in central Oregon would also want to harass cormorants (Shotwell 1989) and if they were allowed to do so, the more glamorous Osprey and other birds in the Crane Prairie Reservoir would certainly also be intentionally or unintentionally disturbed.
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Thirdly, other groups may not have wanted to get involved because they did not want to alienate fishermen by publicly opposing HB 3185. Since some environmental groups are made up of a coalition of various groups, including fishing organizations, this issue could split some environmental groups.
Fourthly, individuals in other groups did not wish to oppose fishermen wanting HB 3185 because they were fearful that fishermen might not then oppose high seas drift gill nets (section 2-I-2) or oil drilling and mining off the Oregon Coast, which were issues that were coming up that some environmental groups felt much more strongly about than cormorant harassment.
The final reason why some environmental groups did not publicly oppose HB 3185 is that they had bills pending before the