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The Mountain-Prairie Region


U.S. Fish and Wildlife Service
134 Union Boulevard
Lakewood, Colorado 80228

November 8, 1999
Chris Tollefson 202-208-5634
Diane Katzenberger 303-236-7917 ext 408


Responding to increasing concerns about the possible effect of double-crested cormorant populations on recreational fishing, habitat and other migratory birds, the U.S. Fish and WildlifeService today announced that it will develop a comprehensive national cormorant management plan.

The Service published a notice in today's Federal Register of its intent to write an Environmental Impact Statement (EIS) evaluating the species' status, known and perceived impacts on other resources, and potential management strategies. The plan will also consider the administrative, logistical, and socio-economic impacts of various management strategies.

"The Service's responsibility is to maintain healthy cormorant populations across the nation. Our goal is to determine what effects current and projected cormorant populations may be having on commercial and recreational fisheries, and to use the best science available to direct future management," said Service Director Jamie Rappaport Clark.

The Service will evaluate management alternatives in the EIS, based on comments received during a public scoping process that begins with today's publication of a Notice of Intent. As part of this process, the Service will host public meetings at sites across the country to gather public input on potential options. Dates, locations and times of the meetings have not yet been determined, but will be published in a future Federal Register notice.

Potential management alternatives range from continuing present policies to implementing large-scale population control measures on breeding grounds, wintering grounds, and migration areas in the United States.

Populations of double-crested cormorants declined dramatically during the 1950s and 1960s from the effects of human persecution, the pesticide DDT and the overall declining health of many ecosystems, especially that of the Great Lakes. Today, the population is at historic highs, due in large part to the presence of ample food in their summer and winter ranges, federal and state protection, and reduced contaminant levels. The Interior population of cormorants, which includes the Great Lakes region, encompasses 61 percent of the nation's breeding cormorants and it is the

fastest growing of the six major North American cormorant breeding populations. From 1970-1991, in the Great Lakes region of the United States and Canada, the number of double-crested cormorant nests increased from 89 to 38,000, an average annual increase of 29 percent. For the contiguous

United States as a whole, the breeding population increased at an average rate of 6.1 percent per year from 1966-1994, and now stands at approximately 372,000 breeding pairs. Using estimates of one to four non-breeding birds per breeding pair yields an estimated total population of between one and two million birds.

The population resurgence of double-crested cormorants has led to increasing concern about the birds' impact on commercial and recreational fishery resources. Cormorants and other waterbirds such as pelicans and herons can have adverse impacts on fish populations at fish farms, hatcheries, and sites where hatchery-reared fish are released- situations in which fish are concentrated in artificially high densities. Because cormorants are protected by the Migratory Bird Treaty Act, their nests and eggs cannot be disturbed, and birds cannot be captured or killed unless a depredation permit is obtained from the Service.

Since 1972, depredation permits allowing the take of double-crested cormorants have been authorized on a case-by-case basis, usually when negative impacts on aquaculture operations and habitat have been demonstrated. Federal take permits (State permits are also required) for birds causing depredation problems at commercial fish hatcheries and other aquaculture operations are typically issued only after non-lethal methods of control have been shown to be ineffective. The U.S. Department of Agriculture's Wildlife Services Division is responsible for documenting economic losses and for recommending possible bird-control measures.

In 1998, the Service issued a Depredation Order permitting take of double-crested cormorants at aquacultural facilities in 13 states in response to economic losses caused by cormorant depredation. To take cormorants under this depredation order, aquaculturalists must first obtain certification from Wildlife Services that a cormorant depredation problem exists, that they have employed non-lethal techniques to control cormorant depredation, that non-lethal controls have not been effective, and that lethal control is warranted. The effect of cormorants on fish populations in open waters is less clear than at aquaculture facilities. Studies conducted worldwide have repeatedly shown that while cormorants can, and often do, take fish species that are valued in commercial and sport fisheries, those species usually comprise a very small proportion of the birds' diet. One study found that the amount of these fish species consumed by cormorants in natural situations totals much less than 10 percent (generally less than 5 percent) of the quantity caught by commercial or sport anglers.

However, research has not yet established conclusively whether cormorants have the ability to deplete local populations of fish like perch, bass, and walleye pike. It is plausible that this may occur, and the Service is keeping an open mind on the subject as it begins the EIS. More information about cormorants, and a copy of the Notice of Intent to write an EIS, can be found on the Service web site at

"This process offers us a chance to examine the scientific evidence and reach a consensus about the future management of these birds. I urge everyone concerned to make their voices heard as we prepare this document," Clark said.

Written comments on the scope of the EIS should be submitted to the Chief, Office of Migratory Bird Management, U.S. Fish and Wildlife Service, 4401 N. Fairfax Dr., Room 634, Arlington, VA 22203. Comments may also be submitted electronically to the following address: Public comments will be accepted for at least 60 days. The Service will publish the closing date for public comments at the time it announces details of public scoping meetings.

The U.S. Fish and Wildlife Service is the principal Federal agency responsible for conserving, protecting, and enhancing fish, wildlife and plants and their habitats for the continuing benefit of the American people. The Service manages the 93-million-acre National Wildlife Refuge System comprised of more than 500 national wildlife refuges, thousands of small wetlands,

and other special management areas. It also operates 66 national fish hatcheries, 64 fish and wildlife management assistance offices and 78 ecological services field stations. The agency enforces Federal wildlife laws, administers the Endangered Species Act, manages migratory bird populations, restores nationally significant fisheries, conserves and restores wildlife habitat such as wetlands, and helps foreign governments with their conservation efforts. It also oversees the Federal Aid program that distributes hundreds of millions of dollars in excise taxes on fishing and hunting equipment to state fish and wildlife agencies.

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