[Federal Register Volume 63, Number 42 (Wednesday, March 4, 1998)]
[Rules and Regulations]
[Pages 10550-10561]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-5485]
[[Page 10550]]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 21
RIN 1018-AE11
Migratory Bird Permits; Establishment of a Depredation Order for
the Double-Crested Cormorant
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Final rule.
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SUMMARY: The U.S. Fish and Wildlife Service (hereinafter Service)
establishes a depredation order for the double-crested cormorant
(Phalacrocorax auritus). In those States in which double-crested
cormorants have been shown to be seriously injurious to commercial
freshwater aquaculture, and when found committing or about to commit
depredations upon aquaculture stocks, persons engaged in the production
of commercial freshwater aquaculture stocks may, without a Federal
permit, take or cause to be taken such double-crested cormorants as
might be necessary to protect aquaculture stocks.
DATES: This rule is effective March 4, 1998.
ADDRESSES: The complete file for this rule is available for inspection,
by appointment, during normal business hours at U.S. Fish and Wildlife,
Room 634, Arlington Square Building, 4401 N. Fairfax Drive, Arlington,
Virginia.
FOR FURTHER INFORMATION CONTACT: Paul R. Schmidt, Chief, MBMO, U.S.
Fish and Wildlife Service, (703) 358-1714.
SUPPLEMENTARY INFORMATION:
Background
Double-crested cormorant (Phalacrocorax auritus) populations are at
an all-time high in the modern era, and commercial aquaculturists
(especially catfish farmers) in many parts of the country are
experiencing economic losses due to cormorant depredation. Three
avenues currently are available to aquaculturists for dealing with
cormorant depredation problems: (1) birds can be harassed (with shotgun
blasts, fire crackers, propane cannons, or other scare devices) without
a Federal permit; (2) ponds can be fitted with physical barriers (or
exclusionary devices) such as wire or mesh netting that prevent birds
from landing; and (3) private aquaculturists and State-operated fish
hatcheries can apply to the Service for a permit to kill cormorants.
The Service is the Federal agency with the primary responsibility
for managing migratory birds. The Service's authority is based on the
Migratory Bird Treaty Act (MBTA) (16 U.S.C. 703-711), which implements
conventions with Great Britain (for Canada), the United Mexican States
(Mexico), Japan, and the Soviet Union (Russia). The double-crested
cormorant is afforded Federal protection by the 1972 amendment to the
Convention for the Protection of Migratory Birds and Game Animals,
February 7, 1936, United States--Mexico, as amended, 50 Stat. 1311,
T.S. No. 912, as well as the Convention Between the United States of
America and the Union of Soviet Socialist Republics [Russia] Concerning
the Conservation of Migratory Birds and Their Environment, November 26,
1976, 92 Stat. 3110, T.I.A.S. 9073 (16 U.S.C. 703, 712). The take of
double-crested cormorants is strictly prohibited except as may be
permitted under regulations implementing the MBTA. In addition to
Federal statutes, the double-crested cormorant may also be protected by
State regulations.
Regulations governing the issuance of permits for migratory birds
are authorized by the MBTA and subsequent regulations (50 CFR Parts 13
and 21). Regulations in Subpart D of Part 21 deal specifically with the
control of depredating birds. Section 21.41 outlines procedures for
issuing permits. Sections 21.43 through 21.46 deal with special
depredation orders for specific species of migratory birds to address
particular problems in specific geographical areas, establishing a
precedent for species and geographic treatments in the permitting
process. Service policies for issuing depredation permits for
aquaculture were described by Trapp et al. (1995).
Federal responsibility for the management of depredating wildlife,
including migratory birds, lies with the Wildlife Services (WS)
formerly Animal Damage Control program of the U.S. Department of
Agriculture's Animal and Plant Health Inspection Service. The primary
authority for WS activities is the Animal Damage Control Act of 1931,
as amended, (7 U.S.C. 426-426c). Animal damage control activities are
conducted at the request of, and in cooperation with, other Federal,
State, and local agencies; private organizations; and individuals.
Management responsibilities of WS in the cormorant-aquaculture conflict
were reviewed by Acord (1995).
Commercial Aquaculture Industry
Aquaculture, the cultivation of finfish and invertebrates in
captivity, has grown exponentially in the past several decades (Price
and Nickum 1995). The five principal aquaculture fish species in the
United States are catfish, trout, salmon, tilapia, and hybrid striped
bass. There are also two categories of non-food fish: baitfish and
ornamental fish (U.S. Department of Agriculture, 1995). While each of
these industries has its own unique set of bird depredation problems,
they all share a basic concern for developing and implementing the best
methods for protecting fish stocks from predation.
The market for channel catfish (Ictalurus punctatus) is the largest
segment of the aquaculture industry, and the one which is perhaps most
susceptible to predation by cormorants. The catfish accounts for about
one-half of the value of aquaculture in the United States.
The number of catfish farms in the United States increased 44
percent between 1982 and 1990 (from 1,494 to 2,155). Most of this
increase occurred between 1982 and 1987. Growth was fairly steady
throughout the 1980s, with production leveling off in the past few
years. Production was estimated at 224,875 metric tons (247,933 short
tons, or 496 million pounds, or 225 million kilograms) worth $353
million in 1993 and is expected to expand 5-7 percent annually due to
increasing sales prices.
Mississippi is the center of catfish production, producing 75-80
percent of the United States output. Alabama, Arkansas, and Louisiana
are also major producers. California, Florida, Illinois, Kentucky,
Missouri, North Carolina, Oklahoma, South Carolina, Texas, and Virginia
also produce catfish and all have, or will have, problems with fish-
eating birds. In the four principal catfish-producing States, the
number of farms increased 67 percent between 1982 and 1992 (from 794 to
1,193); increases in individual States were 24 percent in Alabama (327-
405), 40 percent in Mississippi (316-442), 67 percent in Arkansas (115-
191), and 330 percent in Louisiana (36-155).
The more than 64,300 hectares (158,840 acres) of catfish ponds in
the United States in 1995 represented a 2.3-fold increase from about
28,300 hectares (69,900 acres) in production in the 1970s. The four
principal catfish-producing States accounted for 93 percent of the
total area, with Mississippi alone accounting for about 60 percent.
Catfish ponds range in size from 4-14 hectares (10-35 acres) each, with
a mean size of 5 hectares (12 acres). Farms with 100 hectares (247
acres) in production are not uncommon, and many are more than 400
hectares (990 acres). In the Delta region of Mississippi, catfish farms
average about 100 hectares (247 acres) of ponds, with
[[Page 10551]]
a typical rectangular pond size of 8 hectares (20 acres); ponds are
shallow, ranging from 1-2 meters (3.3-6.6 feet) deep. The large size of
the ponds makes them highly visible to fish-eating birds from the air,
and the high stocking levels (from 5,000 to more than 150,000 fish/
hectare [or 2,000 to more than 60,700 fish/acre], Glahn and Stickley
1995) make them especially attractive to cormorants. The catfish
industry's practice of using large ponds developed in the early 1970s
when cormorant numbers were low.
The physical dimensions of the ponds are the secret to the catfish
farmers' success (as well as the source of today's predation problem).
The most efficient production ponds are circular, but they can not be
harvested as easily. So, the ponds are generally rectangular and can be
as wide as 80-95 meters (262-312 feet). At harvest time, crews drag 100
meter (325 foot) wide seine nets strung between tractors on both sides
of the rectangular ponds along the length of each pond. Undersize fish
slip through the mesh and are harvested the next year. Because catfish
farmers stock more than one year class of fish in a pond, it is not
possible to drain the ponds and to reconfigure them to a size and shape
that can be covered easily with bird-excluding nets. Also, the levees
between the ponds are not wide enough to install extensive net
structures and yet leave room for tractors to maneuver. Thus, several
economic factors (e.g., low profit margin, the cost to modify the
ponds, and a heavy investment in current harvest technologies) combine
to preclude major changes in pond shape and size at the present time.
Population Status of the Double-crested Cormorant
The size of the North American breeding population of the double-
crested cormorant was recently estimated at about 360,000 pairs (Hatch
1995). Using values derived from the published literature of 1-4
nonbreeding birds for each breeding pair yields an estimated total
population of about 1-2 million birds (Hatch 1995).
The double-crested cormorant breeds widely throughout much of
coastal and interior North America. As of 1992, it had been found
breeding in 40 of the 50 United States, all 10 Canadian provinces, and
in Mexico, Cuba, and the Bahamas (Hatch 1995). However, it is not
uniformly distributed across this broad area. Sixty-one percent of the
breeding birds belong to the Interior population, while another 26
percent belong to the Atlantic population. Two major areas of
concentration are apparent in the vast range of the Interior
population: (1) the prairie lakes of Alberta, Manitoba, and
Saskatchewan (which account for 69 percent of the Interior population);
and (2) the U.S. and Canadian Great Lakes (accounting for another 12
percent).
Seven political units account for 70 percent of the North American
breeding birds, with Manitoba alone accounting for 36 percent. Thirty
(52 percent) of the 58 political units listed by Hatch (1995) each
harbor fewer than 100 breeding pairs. In the catfish-producing States
identified by Price and Nickum (1995), only Florida and California have
sizeable breeding populations.
In the south-central United States (Arkansas, Louisiana,
Mississippi, and west Tennessee), the double-crested cormorant has been
known since pre-colonial times and has been recorded as an occasional
breeder throughout the swampy forests of the region since at least the
early 1800s (Jackson and Jackson 1995). Jackson and Jackson predicted
that (in the absence of major limiting factors) the cormorant will once
again become a regular member of the mid-South breeding avifauna, with
birds dispersed more widely because of reservoir construction and with
concentrations expected in the vicinity of aquaculture facilities.
The double-crested cormorant has always been widely distributed as
a breeding species. The only suspected instance of range expansion in
the 20th century is in the United States and Canadian Great Lakes,
which apparently were colonized by birds expanding eastward from the
Canadian prairies beginning with Lake Superior about 1913 and ending
with lakes Erie and Ontario in the late 1930s (Weseloh et al. 1995). It
is possible, however, that these events represented recolonization of
former (but previously undocumented) breeding localities from which the
species was extirpated before 1912. For example, although Barrows
(1912: 67) knew of no breeding records for Michigan, he noted that it
was ``generally distributed over the State during the migrations''
(with specimens from almost every county) and speculated that
``probably there are few sheets of water any size within our limits
which are not visited by this bird at least occasionally.''
The core of the wintering range (i.e., the regions of greatest
density) did not change appreciably between 1959-1972 and 1959-1988
(Root 1988: 11, Sauer et al. 1996b). Cormorant wintering populations
are concentrated in coastal States and Provinces, from North Carolina
to Texas in the east and from California to British Columbia in the
west. In the midsouth, there also are appreciable concentrations inland
from the coast (e.g., east Texas, eastern Oklahoma, southeastern
Arkansas, west-central Mississippi, and northeastern Alabama). Of the 9
catfish-producing States for which Christmas Bird Count data are
available, 6 have indices of relative abundance that exceed the
national mean; the median abundance in these 6 States (including the
major catfish-producers of Alabama, Louisiana, and Mississippi) was 2.0
times the national mean (range: 1.4-9.6).
The scattered occurrence of early winter stragglers throughout much
of the interior of the continent as far north as Minnesota and southern
Saskatchewan (Sauer et al. 1996b) is probably a natural phenomenon of
longstanding (i.e., it probably does not represent a northward
expansion of the wintering range). As evidence of this, we find that 11
percent of 227 winter recoveries (December-February 1923-1988) of birds
banded in Saskatchewan, Lake Huron, and eastern Lake Ontario were from
latitudes north of the major catfish-producing States of Alabama,
Arkansas, Louisiana, and Mississippi (Dolbeer 1991). Forty percent of
these 227 winter recoveries are from 1 deg. blocks of latitude and
longitude that intersect the Gulf Coast and another 22 percent are from
degree blocks that intersect the main stem of the Mississippi River.
Analysis of 5,589 band recovery records for the period 1923-1988
(Dolbeer 1991) revealed that southward movement from areas north of
latitude 42 deg. N occurs primarily in October and November. Cormorants
of all ages are at their greatest median distance from northern nesting
areas--about 1,900 kilometers (1,200 miles)--from December through
March.
Cormorants nesting in Canada and the northern United States from
Alberta to the Gulf of St. Lawrence migrate in winter primarily to the
southern United States between Texas and Florida. There is considerable
mixing and overlap in winter of nesting populations from widely
divergent areas. From 38 to 70 percent of the birds from Saskatchewan
through the Great Lakes region winter in the lower Mississippi Valley
(States of Arkansas, Louisiana, and Mississippi) as do 10 percent of
the birds from such disparate areas as Alberta and the New England
coast (Dolbeer 1991). In other words, the major catfish-producing
States of the lower Mississippi may be envisioned as lying at the apex
of an inverted triangle, with cormorants from a 3,000 kilometer (1,860
mile) expanse of breeding range being funneled into the region in the
winter by topographic features and the flow of the major rivers. In
commenting on this funneling effect,
[[Page 10552]]
Jackson and Jackson (1995) noted that ``It is a most unfortunate
coincidence that the very heart of the catfish-farming industry is
located in the Mississippi Delta at the confluence of the Arkansas and
Mississippi rivers.''
Our knowledge of double-crested cormorant population trends before
1959 is based on fragmented and largely anecdotal accounts from
scattered portions of the range. Syntheses of much of this information
(Hatch 1995, Weseloh et al. 1995, and Jackson and Jackson 1995) reveal
the following general patterns: (1) by 1900, cormorant numbers had been
reduced, and their range possibly restricted, by human persecution and
the extensive drainage and degradation of natural wetlands; (2) the
widespread construction of reservoirs and impoundments (beginning in
the 1920s), in concert with sport fish stocking programs and the
creation of refuges and other conservation lands (beginning in the
1930s), had beneficial effects on cormorant numbers; (3) the widespread
use of DDT and other pesticides (beginning in the 1940s) had
devastating effects on cormorant reproductive success, with the result
that populations reached their lowest point in the mid-1970s; (4) the
ban on DDT in 1972 and the general decrease in levels of environmental
contamination, in concert with development of the catfish industry in
the mid-1970s, created a favorable environment for the growth of
cormorant populations.
Quantitative information on double-crested cormorant population
trends is available from three sources: (1) Breeding Bird Survey data
(1966-1994), (2) Christmas Bird Count data (1959-1988), and (3)
published accounts of censuses of breeding colonies. Trend information
from these sources is discussed in the following paragraphs:
(1) Between 1966 and 1994, the continental breeding population
increased at an estimated rate of 6.1 percent/year (Sauer et al.
1996a). The very high rate of growth in the early years (13.0 percent/
year), and to a lesser extent for the entire period, is partly an
artifact of the extremely small population in the early years of the
survey period (late 1960s and early 1970s). Compared to the earlier
(1966-1979) time period, the growth of the continental and Canadian
populations appears to have slowed appreciably in the later (1980-1994)
period; however, the U.S. population has continued to show a
significant rate of increase in the 1980s and 1990s, apparently due
primarily to the continued rapid growth of populations in the mountains
and plains States. The only significant declines noted were in the West
Coast region (1966-1994) and in North Dakota (1980-1994), although the
West Coast trend appears to be contradicted by rather dramatic site-
specific increases in British Columbia, Washington, and California
(Carter et al. 1995). Most of the recent increase in numbers has
occurred within the known historical breeding range (Hatch 1995).
(2) Between 1959 and 1988, the continental wintering population
increased at an average rate of 7.3 percent/year (Sauer et al. 1996b);
significant increases were registered for 17 of the 20 States or
Provinces for which data were available. Trends are available for 9 of
the primary catfish-producing States; 6 of these States (Alabama,
Louisiana, Mississippi, Oklahoma, Texas, and Virginia) have trends
(median 16 percent, range 12-19 percent) that are well above the
continental average. Most of the localities in the mid-South for which
information is available show dramatic population increases between the
mid-1970s and the early 1990s, with the trends paralleling a similar
magnitude of growth in the area of catfish ponds in the region during
the same period (Jackson and Jackson 1995).
(3) Rather dramatic increases in breeding pairs are documented at
colonies in the Great Lakes (Weseloh et al. 1995), the St. Lawrence
River and associated waters (Chapdelaine and B deg.dard 1995), New
England (Krohn et al. 1995), the West Coast (Carter et al. 1995), and
elsewhere (Weseloh et al. 1995). The trends documented by these studies
generally parallel those from the Breeding Bird Survey and the
Christmas Bird Count.
Foraging Behavior of the Double-crested Cormorant at Aquaculture
Facilities
Daily Movements and Activity Budgets
In the Mississippi Delta, cormorants fly an average of 16
kilometers (25 miles) from their night roosts to feeding sites. Each
bird spends about 18 percent of daylight hours feeding; 88 percent of
their foraging is done at catfish ponds and 12 percent near roost
sites. The average cormorant forages for 60 minutes each day, but
spends just 20 minutes underwater in actual pursuit of fish (King et
al. 1995).
Feeding Rates
Feeding rates may be dependent on the size and abundance of the
available fish and the metabolic demands of the birds, and can be quite
variable. Actively feeding cormorants in commercial catfish ponds
capture an average of about 5 fish/cormorant/hour (Stickley 1991,
Stickley et al. 1992), but can vary from 0-28 (Schramm et al. (1984).
Partly because of this variability, the rate of 5 fish/cormorant/hour
reported by Stickley et al. (1992) is highly skewed; the median was
only 2 fish/cormorant/hour, and the mean was equaled or exceeded at
only 3 (21 percent) of the 14 ponds studied. Stickley et al. (1992) did
not find a significant relationship between the mean number of
cormorants present and the number of catfish consumed, but ponds with
40 or more cormorants generally had a feeding rate of 1 or fewer fish/
cormorant/hour. Similarly, cormorant feeding rates were not related to
the density of fingerling catfish, density of all catfish (all size
classes combined), or mean length of fish.
Diet Composition
Cormorants eat a wide variety of prey items, and there is thus a
great deal of variation in prey composition, both geographically and
seasonally. Nearly all of the published information on diet composition
at aquaculture facilities has been gathered in the vicinity of catfish
farms in the southeastern United States (Bivings 1989, Conniff 1991,
Glahn and Stickley 1992, Glahn et al. 1995, and Glahn and Brugger
1995). These studies show that, among birds actively feeding on catfish
ponds, the average proportion of catfish in the winter diet (by number)
is most commonly in the range of 50-55 percent. The proportion varies
seasonally from less than 30 percent in October and November to more
than 80 percent in February, March, and April.
Prey Size
Although cormorants are capable of taking catfish up to 42
centimeters (16 inches) in length (Campo et al. 1993), studies
repeatedly have shown that the vast majority of catfish caught by
cormorants at commercial facilities are in the range of 7-20
centimeters (3-8 inches), with most averaging about 10-15 centimeters
(4-6 inches) (Schramm et al. 1984, Stickley 1991, Stickley et al.
1992). This range of prey sizes is remarkably close to that of prey
taken by cormorants in natural freshwater habitats. In five such
studies (Durham 1955, Hirsch 1986, Haws 1987, Hobson et al. 1989, Campo
et al. 1993), prey size ranged from 6-21 centimeters (2-8 inches), with
a median value of about 12 centimeters (5 inches).
Prey Preferences
Lacking a precise knowledge of the species composition and size
distribution of the prey population, it is impossible to make
definitive
[[Page 10553]]
statements about prey preferences. However a few tendencies are
apparent. For example, the 10-15 centimeter (4-6 inch) fingerling
catfish preferred by cormorants in one study represented about 64
percent of the catfish (by number) in the ponds (from Stickley et al.
1992), suggesting that the birds were merely preying on the most
readily available fish. In this same study, 1 of the 14 ponds contained
gizzard shad in addition to catfish. Nineteen shad were consumed for
every catfish eaten, even though the pond contained about 5,100
fingerling catfish/hectare (2,100/acre). The apparent preference for
gizzard shad in this instance may be related to their being more easily
caught, handled, and swallowed by cormorants (the mean handling time
for catfish was 6-7 times greater than that of gizzard shad).
Daily Food Consumption Rates
Estimates of daily food consumption rates of cormorants at or in
the vicinity of aquaculture facilities in the southeastern United
States vary widely, from 208-504 grams (7-17 ounces, or 0.4-1.1 pounds)
(Schramm et al. 1984, Schramm et al. 1987, Bivings et al. 1989, Conniff
1991, Brugger 1993, Glahn and Brugger 1995). The most widely accepted
figure is about 320 grams (11 ounces, or 0.7 pounds) of fish/day, of
which about one-half (or 160 grams [5.5 ounces, or 0.35 pounds]) would
be catfish (Brugger 1993).
Impacts of Double-Crested Cormorants on Aquaculture
With the exception of catfish, quantitative accounts of the impacts
of cormorants on freshwater aquaculture stocks generally are lacking.
The fairly large body of literature that has developed in the past 12
years represents an attempt to assess the impacts of cormorants on the
commercial catfish industry. Synopses of the pertinent literature are
given in the following paragraphs.
In the past, cormorants have been reported only infrequently at
fish hatcheries. For example, questionnaire surveys conducted in 1977
(Scanlon et al. 1979) and 1984 (Parkhurst et al. 1987) indicate that
cormorants were considered to be problems at only 4-5 percent of these
facilities nationwide. Of the more than 90 other (including non-avian)
species mentioned as predators, 45-50 percent were listed more
frequently than cormorants. Purported instances of cormorant damage to
hatchery fish in Texas (Dukes 1987) include the loss of 90 percent of
the smallmouth bass (Micropterus dolomieui) 2-year-old brood stock at
the Jasper facility.
The frequency of occurrence of cormorants at a given catfish pond
is a function of many interacting factors, including: (1) size of the
regional cormorant population; (2) the number, size, and distribution
of catfish ponds; (3) the size distribution, density, health, and
species composition of fish populations in the catfish ponds; (4) the
number, size, and distribution of ``natural'' wetlands in the immediate
environs; and (5) the size distribution, density, health, and species
composition of ``natural'' fish populations in the surrounding
landscape. Cormorants are adept at seeking out the most favorable
foraging sites. As a result, cormorants rarely are distributed evenly
over a given region, but rather tend to be highly clumped or localized.
For example, in 27 weekly surveys at 50 catfish ponds in Humphreys
County, Mississippi, 1987-1988, cormorants were observed at only 9 of
the 50 ponds and only on 14 occasions (Hodges 1989). Thus, it is not
uncommon for many fish farmers in a region to suffer little or no
economic damage from cormorants, while a few farmers experience
exceptionally high losses.
Cormorants clearly respond in a positive way to the presence of
shallow-water ponds stocked with high densities of easy-to-capture prey
fish. For example, within two weeks of stocking 2 ponds in Hendry
County, Florida, with 5-20 centimeter (2-8 inch) fingerling catfish, 12
cormorants were feeding in the ponds and roosting on nearby poles. A
nearby 2.5 hectare (6 acre), 2.5-meter (8-foot) deep pond, stocked with
75,000 3-8 centimeter (1-3 inch) fish in August 1980, had attracted 13
cormorants by September. These birds continued to feed at the pond
throughout the fall and winter, and in spring 1981 they nested in a
nearby cypress dome. By November 1981, about 50 cormorants were feeding
in the pond (Schramm et al. 1984). The positive response of cormorants
to the presence of shallow-water ponds stocked with high densities of
easy-to-capture prey fish (as illustrated above) is clearly a major
factor responsible for their impacts in a variety of aquaculture
situations (e.g., baitfish ponds in Minnesota, koi ponds in Missouri
and elsewhere, ornamental fish ponds in Florida, and catfish ponds in
the southeastern United States and elsewhere).
Assuming averages of 5 fingerling catfish consumed/cormorant/hour
and 30 cormorants/pond (a constant number of feeding birds present
throughout an 8-hour day), the catfish population of a typical pond in
the Mississippi Delta (51,000 fish/hectare in a 8-hectare pond, which
is equivalent to 20,650 fish/acre in a 20-acre pond) would be halved in
167 days (Stickley et al. 1992). However, if actual values were nearer
the median values of 2 fish/cormorant/hour and 15 birds/pond (from
Stickley et al. 1992), the number of days required for the cormorants
to reduce the population by half would be increased to 850 days (a 5-
fold increase).
Of 281 catfish farmers queried on the Mississippi Delta in 1988
(Stickley and Andrews 1989), 87 percent felt that they had a bird
problem. Moderate to heavy cormorant activity (defined as at least 25
birds/day) was reported by 57 percent of Delta farmers. Losses to birds
(harassment costs plus value of fish lost) were estimated at $5.4
million (3 percent of total sales).
Overall, there appears to be little conflict between cormorants and
the food- or game-fish industry in Florida (Brugger 1992), but losses
of food fish, primarily catfish, can be locally severe (Brugger 1995);
for example, cormorants were responsible for the loss of up to 50
percent of the fingerling catfish in open 0.125 hectare (0.31 acre)
ponds during 1991 at the University of Florida.
Although fish of commercial value made up only a small percentage
of the diet of cormorants collected in the vicinity of aquaculture
facilities in central and southeast Arkansas from mid-October to early
December, the finding of a few fish of very high value (e.g., grass
carp with wholesale value of about $4 and koi worth $5-10 each)
suggests that cormorant depredations can be locally or seasonally
severe.
On the Mississippi Delta, cormorants consumed an estimated 18-20
million catfish during the winters of 1989-1990 and 1990-1991, which
was equivalent to 842-939 metric tons (928-1,035 short tons, or 1.86-
2.07 million pounds, or 844-939 thousand kilograms). Based on the cost
of replacing these fish, annual losses to the catfish industry were
estimated at $1.8-2.0 million, which corresponds to about 4 percent of
the estimated catfish standing crop each year. Although losses were
documented over a six-month period, the majority (about 64-67 percent)
occurred in February and March (Glahn and Brugger 1995).
At catfish farms in Oklahoma (with about 324 hectares [800 acres]
of surface water in production) in 1993, cormorants consumed an
estimated 7,196 kilograms (15,900 pounds, or 7.9 short tons) of catfish
valued at $14,000-36,000 (depending on size of the fish consumed), or
about 3-7 percent of Oklahoma catfish sales (Simmonds et al. 1995).
[[Page 10554]]
Cormorant Depredation Permits
Depredation permits to take double-crested cormorants at commercial
aquaculture facilities have been issued by the Fish and Wildlife
Service since 1986. Composite data for a recent two-year period (1993-
1994) show that about 8,200 cormorants were taken each year by 2,261
permit holders. Cormorants represented the majority (about 57 percent)
of the total number of birds killed nationwide; two-thirds of the
cormorants were taken in the southeastern region of the United States,
with substantial numbers also taken in the southwest and the upper
Midwest.
Between 1989 and 1996, the number of permits issued to take double-
crested cormorants in the southeastern United States more than
quadrupled, from 50 to 215 (Coon et al. 1996). The reported take of
4,000-8,000 birds annually has had no noticeable effect on the size of
the regional wintering population.
Mastrangelo et al. (1995) noted that the reported take never
exceeded 68 percent of the authorized take and attributed this to the
frightening effect that lethal control has on bird behavior. Hess
(1994) described a recent study in which catfish farmers at three
complexes in Mississippi were authorized (under Fish and Wildlife
Service permits) to remove as many as 2,500 cormorants in a 19-week
period. Participants were supplied with ammunition and encouraged to
kill as many birds as allowed by the permit. The fact that only 290
birds had been killed by the end of the project was attributed to a
learned behavior by the birds to avoid areas where they might be shot
(Hess 1994).
Environmental Consequences of This Rule
Cormorant Population
The depredation order is expected to result in a moderate increase
in the number of double-crested cormorants taken at aquaculture
facilities. The impact is expected to be localized (e.g., possible
reductions in the size of wintering populations in the immediate
vicinity of catfish farms). To calculate the potential maximum harvest,
we can assume that 42 cormorants (the average number reported taken by
holders of depredation permits in the southeastern United States, 1989-
1995; from Coon et al. 1996) will be shot at each of the about 2,200
catfish farms in the United States. The resultant annual take of 92,400
birds will represent about 5-10 percent of the continental population.
This level of take will be more than offset by the recruitment of young
birds into the population; a reproductive success of 1.7-3.2 young/nest
(Duffy 1995) will equate to a minimum recruitment, at current
population levels, of 612,000 young into the population each year. In
reality, the action is expected to result in only a modest increase in
the number of double-crested cormorants taken at aquaculture
facilities.
Socio-Economic
The rule is expected to reduce the direct economic losses caused by
cormorants at commercial aquaculture facilities. It also will enhance
the effectiveness of current nonlethal control programs, thus reducing
overall damage control costs to producers. The depredation order will
reduce paperwork and costs associated with administering the current
permit system and will promote quicker and more efficient depredation
control operations by shifting responsibility to the individual
aquaculturists. The depredation order will demonstrate cooperation
between the Federal agency responsible for protecting and enhancing
wildlife (Service), the Federal agency responsible for dealing with
wildlife damage issues (WS), and the individual producers in dealing
with a problem that has the potential to expand far beyond the wildlife
management arena.
Other Fish-Eating Birds
Although the action does not authorize the taking of other fish-
eating birds, it is possible that a few birds could be taken
accidentally on occasion. The two species that are most likely to be
confused with the double-crested cormorant are the neotropic cormorant
(Phalacrocorax brasilianus) and the anhinga (Anhinga anhinga). These
species have foraging habits very much like those of the double-crested
cormorant and may occur on or in the vicinity of catfish ponds in the
Gulf Coast States. The likelihood of other fish-eating birds being
mistaken for double-crested cormorants and shot accidentally is not
expected to increase above that which presently occurs . However,
because of a projected increase in the number of producers conducting
lethal control operations for cormorants, it is possible that there
will be a slight to moderate increase in the actual number of other
fish-eating birds (especially neotropic cormorants and anhingas) taken
accidentally. Any negative effects on these species would be extremely
localized, and long-term impacts on populations would be unlikely.
Endangered and Threatened Species
Negligible impacts to endangered or threatened species are expected
under the action. Few endangered or threatened species have ever been
taken by aquaculturists with depredation permits. The likelihood of
endangered or threatened species being taken by accident is not
expected to increase.
Summary of Public Comments
On June 23, 1997, the Service published a proposed rule (62 FR
33960) to establish a depredation order for the double-crested
cormorant. Three hundred and thirty letters or postcards were received
from 347 individuals, businesses, organizations, agencies, and elected
officials during the 60-day public comment period. Some parties
submitted multiple letters, other letters were signed by more than one
entity, and letters from two organizations were supplemented by form
letters or postcards submitted by individual members.
For consistency and standardization in analyzing the comments, each
of the following examples was regarded as one distinct set of comments:
(a) 1 letter from an aquaculture facility signed by 2 individuals, (b)
5 identical letters from 5 different employees of an aquaculture
facility, (c) 2 different letters (signed by the same individual) from
1 aquaculture facility, (d) 3 different letters from a private citizen,
(e) 2 identical letters from an aquaculture-related business signed by
2 different individuals, (f) 1 letter from the Louisiana Catfish
Farmers Association supplemented by 42 identical letters signed by
individual members of LCFA, (g) 1 letter from the Catfish Farmers of
Mississippi supplemented by 112 postcards supporting the position of
CFM and signed by individual members, (h) 7 identical letters from an
aquaculture facility signed by 7 different individuals, (i) 2 different
letters from an elected State official, (j) 1 letter from the National
Audubon Society co-signed by representatives of 6 other environmental
organizations (i.e., American Bird Conservancy, Center for Marine
Conservation, Defenders of Wildlife, Environmental Defense Fund, Izaak
Walton League of America, and World Wildlife Fund), and (k) 1 letter
signed by 13 different Congressmen.
Thus, the 330 letters are considered to represent 161 distinct sets
of comments distributed among segments of the public as follows:
private individuals (52), aquaculture-related businesses (50),
aquaculture organizations (21), environmental organizations (18), State
agencies (13, representing 10 States),
[[Page 10555]]
Federal agencies (5), Federal elected officials (1), State elected
officials (1).
The proposed action was supported by 13 members of the U.S. House
of Representatives (Representatives from the states of Alabama,
Arkansas, Louisiana, and Mississippi), who emphasized the economic
importance of the aquaculture industry in their States and the
potentially devastating impacts of cormorants on that industry.
The action was supported (or at least not opposed) by State
agencies in 9 of the 10 States from which comments were received:
Alabama, Arkansas, Illinois, Louisiana, Mississippi, North Carolina,
Oklahoma, Texas, and Vermont. The Missouri Department of Conservation
questioned why the current permit procedure was inadequate, and noted
that if the depredation order were implemented ``it will be important
to monitor control records to evaluate changes in numbers, locations,
and dates that cormorants are taken.''
The WS--a program of the U.S. Department of Agriculture's Animal
and Plant Health Inspection Service and the only Federal agency that
submitted comments--supported the action, with the recommended addition
of several items (e.g., include roost sites, western States, control on
breeding grounds, sport fisheries, mariculture facilities, and
unintentional or ``incidental'' take of similar species) and
recommended deletion of the certification requirement.
The proposed rule received overwhelming support from aquaculture-
related businesses and organizations. Many of the comments received
from this group expressed concern that the scope of the depredation
order was not broad enough (e.g., expand geographically, include
additional species, add roost control, implement widespread population
control).
Among the scientific and environmental organizations commenting on
the proposed action, it was supported by the Wildlife Management
Institute and the Arkansas Wildlife Federation. The action was opposed
(or at least not supported) by 12 national organizations and 7 State or
local organizations. A sample of the concerns raised by these opponents
includes the following: lack of good scientific data on magnitude of
economic impacts; non-lethal techniques have not been adequately
implemented; will remove incentives for using non-lethal control; will
result in unintentional take of non-target birds; adequate methods
(e.g., non-lethal and permits) are already available; effects on
cormorants and other species should be monitored; geographic scope is
unnecessarily broad; minimize effects on non-target species
(educational materials); does not address spatially-localized nature of
problem; does not address seasonal nature of problem; and sets a
dangerous precedent for other bird species.
Written comments received during the comment period are discussed
in the following summary. Comments of a similar nature are grouped into
general issues. These issues and the Service's response to each are
discussed below.
Issue 1: Numerous individuals and a few organizations, including
the Bass Anglers Sportsman Society (BASS), commented that the
depredation order should be expanded to include situations in which
double-crested cormorants commit depredations on sport fish populations
in public waters.
Service Response: Based on a review of the best available science,
the Service concludes that cormorants generally have only minor direct
impacts on sport fish populations (Trapp et al. 1997). Cormorants are
just one of myriad biotic and abiotic factors, including water quality,
aquatic habitat, natural predation, and angler take, that can affect
sport fish populations. However, the Service also recognizes that there
may be highly localized situations in which cormorants can potentially
impact sport fish populations. These are generally situations in which
sport fish are concentrated in extremely high densities, often by human
activities (e.g., massive releases of hatchery-reared fingerlings,
intensively managed put-and-take fisheries, and temporary congregations
of fish at nearshore spawning sites). The Service currently does not
issue cormorant depredation permits to benefit sport fish populations
in public waters, but is exploring potential options that could be used
to deal on a case-by-case basis with localized cormorant predation when
it has been proven to be a significant problem. Two possible options
include: (1) Modification of release practices for hatchery-reared fish
to reduce their vulnerability to cormorant predation, and (2)
harassment of depredating birds.
Issue 2: Wildlife Services, as well as a majority of
aquaculturists, requested that the depredation order be expanded to
allow lethal take in conjunction with roost dispersal activities.
Service Response: Studies conducted in the Mississippi Delta by WS
over the past 6-7 years indicate that coordinated roost harassment/
dispersal (without lethal take) is a promising technique for diverting
roosting cormorants away from the immediate vicinity of aquaculture
facilities. Typically, the effort has involved coordinated teams of
fish farmers harassing birds as they return to night roosts by shooting
cracker shells, screamers (whistlers), and other nonlethal noise-making
devices. The major objective of coordinated roost harassment is to move
birds from the interior Delta (i.e., the location of major catfish
aquaculture facilities) to sites along the Mississippi River.
During the winter of 1996-1997, WS monitored the movements of 50
cormorants outfitted with radio transmitters and examined the effects
of a Delta-wide roost harassment effort (Tobin and King 1997).
Harassment substantially reduced the fidelity of cormorants to roost
sites (e.g., 11 percent of birds returned to the roost within 48 hours
versus 81 percent at control roosts). Compared to birds from control
roosts, birds from roosts that were harassed tended to move long
distances between successive night roosts (i.e., 0 and 26 km,
respectively) and travelled further to feed (i.e., 22 and 31 km,
respectively). Ninety-six percent of the birds that roosted in the
interior Delta foraged there the next day compared to only 7 percent of
birds that roosted along the Mississippi River, and catfish comprised
80 percent of the diet of birds from Delta roosts versus 20 percent of
the diet of birds from river roosts. The evidence clearly shows that
the roost harassment efforts conducted by WS in conjunction with
commercial fish farmers has been successful in dispersing roosting
cormorants away from the immediate vicinity of aquaculture facilities
on the interior Delta, and is an effective nonlethal means for reducing
cormorant damage at catfish farms.
Wildlife Services contends that the ability to shoot double-crested
cormorants at their night roosts in conjunction with harassment would
make it much easier to disperse them from such areas, and would
probably increase the effectiveness of the technique (e.g., increased
dispersal distance, longer period of roost abandonment). However, the
Service is not aware of any documented evidence that the addition of
lethal take would significantly increase the efficacy of roost
harassment.
Roost dispersal/harassment efforts such as those conducted on the
Mississippi Delta can continue unabated under auspices of WS. The
Service will consider applications for depredation permits for lethal
take of double-crested cormorants at roosts on a case-by-case basis.
The Service will also consider a request for a depredation permit to
take cormorants at roost sites in conjunction
[[Page 10556]]
with a research study designed to determine if lethal take
significantly increases the effectiveness of roost harassment.
Issue 3: Conflicting comments were received on the geographical
focus of the depredation order. Aquaculturists requested that the
geographical extent of the order be expanded, citing actual or
potential problems in States (e.g., western U.S.) not covered by the
proposed rule. Environmentalists noted a lack of documented evidence of
problems in some of the geographical areas (e.g., northcentral and
northeastern U.S.) included in the proposed rule.
Service Response: In the proposed rule, the Service proposed that
the action be applicable to 32 States in the eastern U.S. Based on the
public comments received, the Service re-evaluated the need for a
depredation order based on documented evidence of the magnitude of the
problems that double-crested cormorants posed to commercial aquaculture
in individual States.
The Service concludes that double-crested cormorants pose
significant problems to the commercial aquaculture industry in the
following 12 States in the southcentral and southeastern U.S.: Alabama,
Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North
Carolina, Oklahoma, South Carolina, Tennessee, and Texas. This finding
is based on the following lines of evidence: (1) Existing commercial
catfish industry is sizeable, with predicted continued growth; (2)
sizeable populations of migrant or wintering double-crested cormorants,
with predicted continued growth; (3) documented evidence of economic
losses due to cormorant predation on catfish (Stickley and Andrews
1989, Brugger 1995, Glahn and Brugger 1995, Simmonds et al. 1995); (4)
history of issuing aquaculture depredation permits to take substantial
numbers of double-crested cormorants (Coon et al. 1996); (5) predicted
increase in conflicts between catfish industry and cormorants due to
projected expansion of industry and growth of cormorant population; and
(6) potential conflicts between cormorants and other aquaculture
industries, including baitfish, ornamental fish, and tilapia (Bivings
et al. 1989).
The Service also finds that double-crested cormorants pose
significant problems to the commercial aquaculture industry in the
State of Minnesota. Within the northcentral region of the U.S.
(encompassing eight States), Minnesota accounts for 67 percent of all
aquaculture depredation permits issued, 93 percent of all cormorants
reported taken, and 82 percent of all economic losses claimed. A total
of $388,750 in losses due to double-crested cormorant predation was
claimed by Minnesota aquaculturists in 1997. Most of the aquaculture
conflicts with cormorants in Minnesota involve the baitfish industry,
although a variety of other stocks are also involved (U.S. Fish and
Wildlife Service, unpubl. data).
Individual aquaculture depredation permits will still be available
on a case-by-case basis for dealing with damages caused by cormorants
at commercial aquaculture facilities in States not covered by the
depredation order. The Service will also consider adding additional
States to the depredation order upon receipt of evidence that double-
crested cormorants are responsible for significant economic losses at
aquaculture facilities.
Issue 4: Wildlife Services thought that it was excessive and
burdensome to require aquaculturists to contact one of its State
offices to obtain certification of non-lethal harassment activities
prior to implementing lethal control activities under the depredation
order.
Service Response: Prior to implementing the lethal control
activities authorized by this rule, an aquaculturist must obtain a
statement from WS certifying that his or her facility has a cormorant
depredation problem and that lethal take of cormorants is necessary to
supplement existing non-lethal harassment efforts. This requirement
does not differ substantially from the certification statement that the
Service requires before issuing a depredation permit. The Service
considers this a reasonable and prudent measure that will help to
ensure that (1) the privileges and purposes of the depredation order
are not abused; and (2) non-lethal harassment remains an essential part
of integrated cormorant management activities at aquaculture
facilities.
Issue 5: Both aquaculturists and environmentalists stressed the
need for an accurate system for documenting the number of cormorants
taken under the depredation order, and several environmental
organizations recommended that the reporting requirements be
strengthened.
Service Response: The rule requires that any person exercising the
privileges of the depredation order must keep and maintain a monthly
log recording the date and number of all birds killed each month under
this authorization, that the log must be maintained for a period of
three years (and that three previous years of takings must be
maintained at all times thereafter), and that the log be made available
to Federal and State wildlife enforcement officers upon request. Any
mandated reporting requirement would be difficult to enforce, and the
submitted information difficult to interpret due to non-reporting bias.
The Service intends to supplement the monthly log of cormorants shot
with phone or mail surveys of a stratified random sample of
aquaculturists. This survey is anticipated to provide more reliable and
useful information on levels of take than reports submitted by
individual aquaculturists. These surveys are also subject to OMB
approval under the Paperwork Reduction Act of 1995.
Issue 6: Aquaculturists indicated a desire for a provision to allow
the unintentional (or ``incidental'') take of similar species, while
environmentalists pointed out that any such take would be a potential
problem.
Service Response: Control actions taken under this order can be
effectively implemented without killing other species of birds.
Therefore, authorization to take is limited to double-crested
cormorants. To the extent a person takes a bird or birds other than
double-crested cormorants, it is a violation of the MBTA. In that
event, the Service will exercise its discretion in determining what
enforcement action, if any, is appropriate.
The Service will attempt to minimize the unintentional take of non-
target species by (1) restricting shooting to daylight hours; and (2)
working with WS and nongovernmental organizations to develop
educational identification materials.
Issue 7: Aquaculturists interpreted the proposed rule as applying
only to the owners of aquaculture facilities, which would make on-site
implementation of the depredation order much more restrictive than that
of existing depredation permits.
Service Response: The rule was intended to be applicable to
landowners, operators, and tenants actually engaged in the production
of commercial freshwater aquaculture stocks (plus their employees or
agents). The wording of the depredation order has been changed to more
accurately reflect this fact.
Issue 8: Many aquaculturists suggested that the depredation order
be expanded to include other species of fish-eating birds, such as
egrets and herons, that cause damage at aquaculture facilities.
Service Response: Of the approximately 46 species of fish-eating
waterbirds that occur in freshwater habitats of the contiguous U.S.,
the
[[Page 10557]]
double-crested cormorant is by far the greatest economic threat to
commercial aquaculture because of its abundant and increasing
population, its attraction to certain types of aquaculture facilities,
its habit of foraging in large flocks, and its ability to consume large
quantities of fish daily (i.e., about 320 grams, or 0.7 pounds). This
is reflected in the distribution of aquaculture depredation permits
over the past decade. Nationwide, double-crested cormorants have
accounted for about 57 percent of the individual birds of all species
reported taken under aquaculture depredation permits annually; this
species is an even greater problem in the southcentral and southeastern
U.S., where it has represented about 65 percent of all individuals
taken at aquaculture facilities.
Other species frequently cited as causing damage at aquaculture
facilities include the great blue heron (Ardea herodias), great egret
(Casmerodias albus), and black-crowned night-heron (Nycticorax
nycticorax). Based on a review of the available information, the
Service does not believe that inclusion of these or any other species
of fish-eating birds in the depredation order is warranted at this
time. Individual depredation permits will still be available on a case-
by-case basis for dealing with damages caused by other species of fish-
eating birds.
Thus, while aquaculturists may take unlimited numbers of double-
crested cormorants under the depredation order without need of a
permit, they will still be required to obtain a depredation permit to
take any other species that may be causing economic damages.
Issue 9: Aquaculturists noted that a prohibition against removing
dead cormorants from the aquaculture facility at which they were killed
would present logistical and potential health problems.
Service Response: The Service reviewed this issue and found no
valid reason for prohibiting off-site disposal of carcasses. The
depredation order has been reworded to allow both on-site and off-site
burial or incineration of dead cormorants.
Issue 10: Many respondents in the aquaculture community felt that
State agencies should have more authority in the management of
aquaculture-cormorant depredation conflicts.
Service Response: There is a long tradition of Federal-State
cooperation in the management of migratory bird populations. Typically,
the Service issues broad regulatory guidelines (such as this rule)
while individual States retain the authority to implement regulations
that are more, but not less, strict than the Federal regulations. In
this regard, it is important to note that the depredation order does
not authorize the killing of cormorants contrary to the laws or
regulations of any State, and that the privileges of the depredation
order may not be exercised unless the person possesses any appropriate
State permits that may be required. The Service is committed to working
closely with State (as well as other Federal) agencies in developing
and implementing long-term solutions to the aquaculture-cormorant
problem.
Issue 11: Widespread population management of the double-crested
cormorant, including actions on the breeding grounds, was advocated by
aquaculturists and WS to reduce the size of the North American
population.
Service Response: A widespread, coordinated effort to reduce the
cormorant population would be extremely labor-intensive and expensive,
with little likelihood of long-term success. Furthermore, there is no
guarantee that regional reductions in cormorant populations would
reduce impacts at individual aquaculture facilities. The purpose of the
depredation order is to provide individual aquaculturists an
opportunity to deal with site-specific cormorant depredation problems
in a timely and effective fashion, not to achieve a broadscale
reduction in the continental double-crested cormorant population.
Issue 12: Aquaculturists noted that methods of lethal take other
than shooting (such as netting and traps) may be effective in killing
cormorants, and that such methods should be authorized in the
depredation order.
Service Response: To the Service's knowledge, shooting with
firearms has been the only method employed for the lethal take of
cormorants in aquaculture settings. In the event that other effective
and safe methods of taking cormorants are developed, the Service will
consider adding these to the depredation order.
Issue 13: Aquaculturists requested authorization to use decoys,
vocalizations, and other lures to bring cormorants into closer gun
range.
Service Response: Anything that makes it easier to kill depredating
double-crested cormorants by bringing them into closer range is
considered beneficial to the purposes of the depredation order.
Consequently, language has been inserted allowing the use of such
devices.
The intent of this provision is not to lure cormorants onto
aquaculture facilities from the surrounding landscape (which would
clearly be counter-productive), but to make it easier to shoot birds
that are already present and committing or about to commit depredations
on fish stocks.
Issue 14: Some aquaculturists suggested that the depredation order
be expanded to include mariculture facilities located in brackish and
saltwater situations.
Service Response: In the past decade, the Service has issued a very
limited number of cormorant depredation permits to mariculture
operations. The problems caused by cormorants to mariculture facilities
are not well documented, and are not deemed to be of sufficient
magnitude to warrant their inclusion in the depredation order at this
time. Mariculture operators experiencing significant problems due to
cormorant predation can still apply for individual depredation permits.
Issue 15: Efforts should be made to monitor the numbers of
cormorants taken under the depredation order, as well as trends in
cormorant populations.
Service Response: In addition to gathering information on the
numbers of cormorants shot (see response to Issue 5), the Service
intends to monitor potential impacts of the depredation order on
regional and continental cormorant populations by means of: (a)
Breeding Bird Survey and Christmas Bird Count trend data; (b) breeding
colony survey data; (c) counts of cormorants on waterfowl breeding
pairs surveys; and (d) analysis of band recovery data.
Issue 16: The National Audubon Society et al. and other
environmental groups argued that non-lethal control techniques were
effective in alleviating conflicts between cormorants and commercial
aquaculture and should remain a high priority, while also expressing
concern that the depredation order would effectively discourage
aquaculturists from investing in non-lethal, long-term solutions to
depredation.
Service Response: The Service has long recognized non-lethal
control as the preferred alternative for dealing with cormorant damage
complaints (Trapp et al. 1995), as has WS (Accord 1995). Of the many
non-lethal (exclusionary and frightening) devices tested over the last
decade, none has proven totally effective in deterring cormorants from
aquaculture facilities. Typically, birds learn to avoid or ignore these
devices in a relatively short period of time through habituation. Some
form of behavioral reinforcement (such as limited lethal take) helps to
reinforce and prolong the effectiveness of non-lethal deterrents. In
reality, then, the take of limited numbers of birds will always have to
be considered as a viable option in an effective, integrated
[[Page 10558]]
strategy for minimizing the deleterious effects of cormorants on
aquaculture.
The depredation order does not absolve aquaculturists from the
responsibility of employing non-lethal techniques (see response to
Issue 4); rather, it simply provides them with another tool for
application in an integrated management approach designed to reduce
problems caused by cormorants at their facilities.
The Service believes that the aquaculture industry shares
responsibility for alleviating bird depredation problems and that the
industry should aggressively promote: (1) The design of new facilities
(and the retrofitting of old ones where economically feasible) that
exclude or repel cormorants; and (2) the use of nonlethal deterrents.
The Service also encourages WS to continue an aggressive research
effort to develop effective nonlethal means of alleviating bird
depredation problems in aquaculture.
Issue 17: The Ornithological Council and other scientific and
environmental groups stated their opinion that there is very little
good scientific data and no consensus on the extent and magnitude of
the cormorant predation problem at commercial fish ponds.
Service Response: The Service believes that an objective review of
the available scientific information (as presented in the SUPPLEMENTARY
INFORMATION section) provides an accurate indication of the actual and
potential problems caused by cormorants at commercial aquaculture
facilities, as well as reliable figures on the magnitude of economic
losses. In reviewing Foraging Behavior of the Double-crested Cormorant
at Aquaculture Facilities, the Service synthesized data from 17 peer-
reviewed scientific papers to summarize what is currently known about
daily movements and activity budgets, feeding rates, diet composition,
prey size, prey preferences, and daily food consumption rates. This
information provides the basic background for understanding the nature
of potential interactions between cormorants and aquaculture.
In assessing Impacts of Double-crested Cormorants on Aquaculture,
the Service provided synopses of 12 peer-reviewed scientific papers
that furnished information of a quantitative nature on actual or
potential impacts. For the catfish industry, economic losses in the
Mississippi Delta have been calculated by different methods as about 3
percent of total sales (Stickley and Andrews 1989) or about 4 percent
of the estimated standing crop (Glahn and Brugger 1995), and in
Oklahoma as about 3-7 percent of sales (Simmonds et al. 1995). It is
important to recognize that these are average values. Cormorants rarely
are distributed evenly over a given region, but rather tend to be
highly clumped or localized. Thus, economic losses also tend to be
clumped or localized, with a minority of growers suffering a majority
of losses in a given year. Since the distribution and severity of
economic losses is unpredictable from year to year, it is prudent to
provide all aquaculture producers in the affected States an opportunity
to avail themselves of the privileges of the depredation order.
The Service finds no reason to question the validity or conclusions
of the scientific studies that it has reviewed, but acknowledges that
others might interpret the same data differently. Although it agrees
that better scientific information is always desirable, the Service
must make management decisions using the best information available
while relying on accepted ecological and wildlife management
principles. The Service will continue to review new scientific studies
documenting the impacts of double-crested cormorants on commercial
aquaculture stocks as they become available.
Issue 18: The proposed action appeared to be an application for
recreational hunting to Animal People, who viewed it as a pretext to
kill double-crested cormorants for sport and revenge, not because they
are genuinely a threat or problem.
Service Response: The Service is not establishing a recreational
hunting program. Depredation orders are an established method for
dealing with situations in which migratory birds are causing
significant damage to human interests. Damages to freshwater commercial
aquaculture stocks due to cormorant predation have been well documented
in the scientific literature (see response to Issue 17).
A decision to propose establishment of a depredation order was made
only after: (1) determining that there was documented scientific
evidence that cormorants were indeed a source of severe economic losses
at aquaculture facilities; and (2) evaluating 12 different potential
management options for reducing the problem (U.S. Fish and Wildlife
Service 1997). The depredation order was determined to be the best
alternative. The depredation order authorizes the take of double-
crested cormorants, under limited conditions, for the express purpose
of reducing economic impacts to aquaculture facilities. This rule will
allow aquaculturists to shoot cormorants not for fun, but because they
are causing damage to commercial fish stocks.
Issue 19: Many environmental groups believed that aquaculturists
should modify their ponds to incorporate the use of physical barriers
and other exclusionary devices to reduce the impacts of double-crested
cormorants on fish stocks.
Service Response: This would be an ideal situation if economically
feasible. But the reality is that requiring aquaculturists to retrofit
existing ponds to accommodate physical barriers and other exclusionary
devices would create an economic hardship for small businesses and
local economies. Nevertheless, the Service encourages the aquaculture
industry to aggressively promote the design of new facilities (and the
retrofitting of old ones where economically cost-effective) that
exclude or repel cormorants.
Issue 20: Concern was expressed by one environmental group that the
depredation order would allow an aquaculturist to implement lethal
control of cormorants regardless of whether or not they are a
persistent threat and without having to demonstrate economic impacts
due to cormorant predation.
Service Response: The proposed rule and the Environmental
Assessment (U.S. Fish and Wildlife Service, 1997) established that
double-crested cormorants can cause severe damage at aquaculture
facilities under certain circumstances, and that lethal take (in
conjunction with a suite of non-lethal harassment techniques) was an
appropriate depredation control action. The depredation order merely
provides individual aquaculturists the opportunity to deal with site-
specific cormorant depredation problems in a timely and effective
manner.
Issue 21: The National Audubon Society et al. and others stated
that the proposed action does not acknowledge the seasonal nature of
cormorant depredation problems, and suggested that authority to take
cormorants should be limited to those months when depredation is most
common.
Service Response: The intent of the depredation order is to give
aquaculturists the flexibility to take double-crested cormorants
whenever they are present at their facilities and committing or about
to commit depredations on fish stocks. The Service anticipates that the
take of depredating cormorants at aquaculture facilities will be self-
limiting and directly related to the numbers of birds present (e.g.,
catfish producers in the southcentral and southeastern U.S. will take
birds
[[Page 10559]]
primarily in the winter months, and baitfish producers in Minnesota
will take birds primarily in the summer months). Thus, while the
Service acknowledges the seasonal nature of cormorant depredation
problems, it does not believe that seasonal restrictions are necessary.
Issue 22: The creation of a depredation order for the double-
crested cormorant establishes a dangerous precedent for other bird
species and is contrary to the purposes of the Migratory Bird Treaty
Act.
Service Response: The MBTA provides strong measures for the
protection and conservation of migratory birds, while at the same time
providing opportunities for people to use the migratory bird resource
for sport, recreation, and scientific endeavors. The MBTA also provides
considerable flexibility for dealing with situations where birds may
come into conflict with human interests, such as the aquaculture-
cormorant situation (Trapp et al. 1995).
Depredation orders have been in place for various species of
migratory birds since at least 1974. Brief descriptions of each of the
existing depredation orders authorizing take of designated species
without need of a Federal permit follow:
Blackbirds (Agelaius spp., Euphagus spp., Xanthocephalus
xanthocephalus), cowbirds (Molothrus spp.), grackles (Quiscalus spp.),
crows (Corvus brachyrhynchus, C. caurinus, C. ossifragus), and magpies
(Pica spp.) ``when found committing or about to commit depredations
upon ornamental or shade trees, agricultural crops, livestock, or
wildlife, or when concentrated in such numbers and manner as to
constitute a health hazard or other nuisance'' (50 CFR 21.43).
Horned larks (Eremophila alpestris); golden-crowned, white-crowned,
and other crowned sparrows (Zonotrichia spp); and house finches
(Carpodacus mexicanus) ``when seriously injurious to agriculture or
other interests'' in California (50 CFR 21.44).
Purple gallinules (Porphyrula martinica) ``when found committing or
about to commit serious depredations to growing rice crops'' in
Louisiana (50 CFR 21.45).
Scrub jays (western scrub-jays, Aphelocoma californica) and
Steller's jays (Cyanocitta stelleri) ``when found committing or about
to commit serious depredations to nut crops'' in Washington and Oregon
(50 CFR 21.46).
Issue 23: Several organizations and individuals questioned why the
current procedure of issuing individual depredation permits to
aquaculturists experiencing problems with cormorants was not adequate.
Service Response: Because of the administrative procedures involved
in the issuance of permits, there may be lag time of several weeks
between an aquaculturist's request for a permit and his or her receipt
of a permit authorizing lethal take; in the interim, cormorant
depredations can result in significant economic losses. The depredation
order will allow aquaculturists to employ lethal take as soon as it
becomes apparent that cormorant depredation is a problem.
Issue 24: The Ornithological Council expressed concern that the
estimated take of 92,000 double-crested cormorants annually was ``way
too high,'' as it could represent a tremendous proportion of the North
American population.
Service Response: The figure of 92,400 cormorants published in the
proposed rule was a calculation of the potential maximum harvest, and
was presented as a worst-case scenario. The Service estimates that
adult and juvenile cormorants will be taken in proportion to their
occurrence in the population, and that the annual take will never
exceed 10 percent of the total population. Enactment of the depredation
order is expected to result in only a modest increase in the number of
depredating cormorants killed at aquaculture facilities under
depredation permits (e.g., about 10,900 birds currently reported killed
annually in the 13 affected States), and is not likely to have a
detrimental impact on the population.
Cormorants are difficult to kill in large numbers, as indicated by
one study (Hess 1994) in which investigators were able to kill only
11.6 percent of the number authorized (2,500) over a 19-week period.
From 1989-1995, aquaculturists in the southeastern U.S. reported taking
only about 65 percent of the cormorants that they had been authorized
to take (Coon et al. 1996). Impacts of the depredation order on double-
crested cormorants will be monitored by reviewing several independent
sets of data (see responses to Issues 5 and 15).
Issue 25: The Wisconsin Society for Ornithology and others pointed
out the value of bird band recovery information.
Service Response: Substantial numbers of double-crested cormorants
have been banded on their breeding grounds. Recoveries of banded birds
at aquaculture facilities provides valuable scientific information on
the origin of birds causing depredation problems, and are potentially
useful for documenting effects of the depredation order on cormorants.
Aquaculturists will be encouraged to submit band recovery information
to the Bird Banding Laboratory via its toll-free telephone number.
Issue 26: The Arkansas Game and Fish Commission and several other
respondents recommended that non-toxic shot be required for use in all
control efforts using shotguns.
Service Response: The Service agrees, and language requiring the
use of nontoxic shot has been included in the depredation order.
The detrimental impacts of lead shot on waterfowl and non-target
species such as bald eagles (Haliaeetus leucocephalus), as well as
secondary impacts on the environment, are well-documented (U.S. Fish
and Wildlife Service, 1986). Based on this evidence, the Service
adopted regulations (50 CFR 20.108) in 1991 requiring the use of
nontoxic shot for hunting waterfowl, coots, and certain other species
throughout the U.S. Recent studies (e.g., Locke et al. 1991, DeStefano
et al. 1992, Elliott et al. 1992, Blus 1994, Daury et al. 1994, and
Franson and Hereford 1994) further document lead poisoning in a variety
of migratory bird species due to the ingestion of spent lead shot.
Holders of aquaculture depredation permits in Minnesota have been
required to use steel shot since 1989, while permittees in the
southeastern U.S. have not heretofore been required to use nontoxic
shot. Beginning in 1998, all aquaculture depredation permits issued by
the Service will require the use of nontoxic shot. As producers of
commodity products marketed for human consumption, aquaculturists have
a vested interest in maintaining high environmental quality standards
on their facilities.
The 30-day delay between publication of this final rule and its
effective date is provided by the Administrative Procedures Act (5
U.S.C. 553(d)). March is a critical time for the fish farmers as the
cormorants congregate heavily in the areas in question feeding in
preparation for the Spring migration north. Since this a peak
depredation time on catfish, the Service is providing relief to the
farmers by allowing a streamlined process of dealing with cormorant
depredation. Further, the Service has been directed to move on this
issue by report language from the House and Senate dated October 22,
1997, mandating that the Service effectively respond to this issue by
January 1, 1998. Therefore, the Service believes good cause exists to
waive the 30-day effective date.
[[Page 10560]]
National Environmental Policy Act
In accordance with the National Environmental Policy Act of 1969,
the Service prepared an Environmental Assessment, and issued a Finding
of No Significant Impact. Copies of these documents are available from
the Chief, Office of Migratory Bird Management, U.S. Fish and Wildlife
Service, 4401 North Fairfax Drive, ms 634-ARLSQ, Arlington, VA 22203.
Endangered Species Act Consideration
A consultation was conducted to ensure that actions conducted in
accordance with the depredation order will not likely jeopardize the
continued existence of endangered or threatened species or result in
the destruction or adverse modification of their critical habitat.
Findings from this consultation are included in a biological opinion,
which is available for public inspection at the address indicated under
the caption ADDRESSES.
Regulatory Flexibility Act, Executive Order (E.O.) 12866 and Paperwork
Reduction Act
Based on the economic impacts discussed in ``Impact of Double-
crested Cormorants on Aquaculture,'' the Service determined under the
Regulatory Flexibility Act of 1980 (5 U.S.C. 601 et seq.) that this
rule would not have a significant effect on a substantial number of
small entities, which include businesses, organizations and
governmental jurisdictions. This rule was reviewed by the Office of
Management and Budget under E.O. 12866.
The Service examined the rule under the Paperwork Reduction Act of
1995 and found that it does contain information collection
requirements. OMB has issued the following emergency information
collection number 1018-0087, which expires August 31, 1998. Information
collection is required to better enable the Service to assess the
benefits of the depredation order on aquaculturists and to assess
impacts to the double-crested cormorant population. Burden hours to
aquaculturists are calculated as follows: An average of 41 birds may be
taken by each of some 2,200 aquculturists per season. An estimated
total of 800 hours will be required to keep and maintain the monthly
logs, and produce the logs for inspection, yielding an average of 22
minutes per aquaculturists per year.
Unfunded Mandates
The Service has determined and certifies, in compliance with the
requirements of the Unfunded Mandates Act, 2 U.S.C. 1502 et seq., that
this rule will not impose a cost of $100 million or more in any given
year on local or State government or private entities.
Civil Justice Reform--Executive Order 12988
The Department, in promulgating this rule, has determined that
these regulations meet the applicable standards found in Sections 3(a)
and 3(b)(2) of Executive Order 12988.
References Cited
A complete list of all references cited herein is available upon
request from John L. Trapp, Office of Migratory Bird Management, U.S.
Fish and Wildlife Service, 4401 North Fairfax Drive, ms 634-ARLSQ,
Arlington, Virginia 22203.
Author
The primary author of this rule is John L. Trapp, Office of
Migratory Bird Management.
List of Subjects in 50 CFR Part 21
Exports, Hunting, Imports, Reporting and recordkeeping
requirements, Transportation, Wildlife.
Regulation Promulgation
Accordingly, the Service hereby amends part 21, Subpart D, of
subchapter B, chapter I, title 50 of the Code of Federal Regulations,
as set forth below:
PART 21--[AMENDED]
1. The authority citation for part 21 continues to read as follows:
Authority: Pub. L. 95-616, 92 Stat. 3112 (16 U.S.C. 712(2)).
2. Section 21.47 is added to Subpart D to read as follows:
SUBPART D--CONTROL OF DEPREDATING BIRDS
* * * * *
Sec. 21.47 Depredation order for double-crested cormorants at
aquaculture facilities.
The Service examined the rule under the Paperwork Reduction Act of
1995 and found that it does contain information collection
requirements. OMB has issued the following emergency information
collection number, 1018-0097, which expires on August 31, 1998.
Information collection is required to better enable the Service to
assess the benefits of the depredation order on aquaculturists and to
assess impacts to the double-crested cormorant population. Burden hours
to aquaculturists are calculated as follows: an average of 41 birds may
be taken by each of some 2,200 aquculturists per season. An estimated
total of 800 hours will be required to keep and maintain the monthly
logs, and produce the logs for inspection, yielding an average of 22
minutes per aquaculturists per year. Landowners, operators, and tenants
actually engaged in the production of commercial freshwater aquaculture
stocks (or their employees or agents) in the States of Alabama,
Arkansas, Florida, Georgia, Kentucky, Louisiana, Minnesota,
Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, and
Texas may, without a Federal permit, take double-crested cormorants
(Phalacrocorax auritus) when found committing or about to commit
depredations to aquaculture stocks on the premises used for the
production of such stocks: Provided that:
(a) Double-crested cormorants may be taken by shooting during
daylight hours only, and only when necessary to protect freshwater
commercial aquaculture and State-operated hatchery stocks from
depredation; none of the birds so taken may be sold; and all dead birds
must be buried or incinerated, except that any specimens needed for
scientific purposes as determined by the Director must not be
destroyed, and information on birds carrying metal leg bands may be
submitted to the Bird Banding Laboratory by means of a toll-free
telephone number at 1-800-327-BAND (or 2263).
(b) Double-crested cormorants may be shot at freshwater commercial
aquaculture facilities or State-operated hatcheries only in conjunction
with an established non-lethal harassment program as certified by
officials of the Wildlife Services' program of the U.S. Department of
Agriculture's Animal and Plant Health Inspection Service.
(c) Double-crested cormorants may be taken with firearms only
within the boundaries of freshwater commercial aquaculture facilities
or State-operated hatcheries, and persons using shotguns are required
to use nontoxic shot.
(d) Persons operating under the provisions of this section may use
decoys, taped calls, or other devices to lure birds committing or about
to commit depredations within gun range.
(e) Any person exercising the privileges of this section must keep
and maintain a log recording the date and number of all birds killed
each month under this authorization, that the log must be maintained
for a period of three years (and that three previous years of takings
must be maintained at all times thereafter), that the log and any
related records be made available to Federal or State wildlife
enforcement officers upon request during normal business hours.
(f) Nothing in this section authorizes the killing of double-
crested cormorants
[[Page 10561]]
contrary to the laws or regulations of any State, and none of the
privileges of this section may be exercised unless the person possesses
the appropriate State permits, when required; nor the killing of any
migratory bird species other than double-crested cormorants when
committing or about to commit depredations to aquaculture stocks.
(g) The authority granted in this section will automatically expire
on April 30, 2005, unless revoked or specifically extended prior to
that date.
Dated: January 30, 1998.
Donald J. Barry,
Acting Assistant Secretary for Fish and Wildlife and Parks.
[FR Doc. 98-5485 Filed 3-3-98; 8:45 am]
BILLING CODE 4310-55-P
