Double-crested Cormorant Management In New York
Increase in Cormorant Populations
Double-crested cormorant (Phalacrocorax auritis) populations greatly increased across New York during the 1990s into the early part of this century. This is likely a result of a cleaner environment and fewer pesticides causing reproductive problems. Large nesting colonies are a sight to behold, but high densities of nesting cormorants are not without problems.
- In Lake Champlain, cormorants destroy vegetation on nesting islands in Vermont, which harms populations of common terns, a state-threatened species.
- The survival of common terns is also threatened on islands occupied by cormorants on Oneida Lake (PDF). In addition, thousands of cormorants present during the fall migration have raised concerns about their effect on ecologically and economically important fisheries.
- In the eastern basin of Lake Ontario, cormorants have been found to be a significant predator fish species that are of recreational importance1.
- On the Niagara River, high cormorant densities threaten sensitive island habitats that support nesting species of concern.
Role of the NYSDEC
The Department's mission includes a responsibility to manage fish and wildlife resources for the benefit of current and future generations. It is not an easy job. It often requires balancing competing interests to find the course of action that will protect or manage species, while not destroying another. The profession of wildlife management has grown in sophistication and considers the human side of the equation. We also pay attention to social and economic issues and consider people's values and desires in developing our management plans. We are currently involved in a series of cormorant studies and management activities with our counterparts in other states, universities, the federal government, and Canada. Sound science is at the base of our investigations. It requires that we keep an open mind, document our observations, and learn from experience.
Management of Double-Crested Cormorants to Protect Public Resources
For more than 20 years, DEC's Division of Fish and Wildlife (DFW), in cooperation with U.S. Department of Agriculture Wildlife Services, has carried out integrated double-crested cormorant management programs to alleviate and prevent conflicts with public resources at specific problem areas in New York. Things changed in 2016 when a federal court decision restricted management options. This reduced the ability to mitigate conflicts in which public resources are affected. Cormorant population control efforts prior to 2016 have helped reduce these conflicts, but continued action is needed. Specifically, DFW can no longer manage cormorants to protect sport fish, but can initiate limited actions to protect rare birds and their habitat.
DFW manages cormorants in five areas of New York (eastern Lake Ontario, St. Lawrence River, Oneida Lake, Buffalo Harbor/Niagara River, and Lake Champlain/eastern Adirondacks). Actions include:
- egg-oiling and nest destruction
- non-lethal deterrents to nesting
- habitat modification
- exclusion techniques
- spring and fall hazing on Oneida Lake
- limited lethal take of birds statewide to complement and increase effectiveness of other measures
Status of Management Actions
Current actions are a continuation of measures used in the past, with the exception that DFW may no longer implement actions directed at protection of important fisheries and must comply with strict limits at specified locations. While ongoing efforts help to reduce impacts at specific locations, management cannot be adaptable to changing conditions or when concerns arise in new locations. Limits on permissible take also reduce effectiveness where and when numbers exceed authorized control thresholds.
DEC applied for and received a permit in the spring of 2018 to take limited actions to protect rare birds and sensitive habitats at very specific sites in Lake Ontario, Lake Erie, Lake Champlain, Oneida Lake, and the St. Lawrence and Niagara Rivers. In total, DEC may remove up to 4,980 cormorant nests and 965 birds in efforts to reduce impacts at these sites. Currently, there is no provision to provide protection to fisheries important to anglers, although actions underway will provide some benefit.
The U.S. Fish and Wildlife Service (USFWS), the federal Agency with oversight of cormorants, is studying the issue in cooperation with the States, including New York. USFWS is now beginning a process to look at fisheries impacts caused by cormorants. DEC will participate in the effort to ensure that effective management strategies to protect all natural resources are considered in future plans developed by the USFWS.
We hope that this process will result in a more comprehensive cormorant management plan that encompasses the range of public resource concerns that exist, but the process may not be completed for several years.
