Oneida Lake Cormorant Hazing
In order to minimize impacts of double-crested cormorant (DCC) predation on the fish community of Oneida Lake, DCC management activities have been undertaken since 1998. The U.S. Department of Agriculture's Animal and Plant Health Inspection Service (APHIS) conducted cormorant management activities from 1998 through 2009. Along with other activities, APHIS conducted "hazing" (non-lethal) in the spring, summer, and fall to move birds off of the lake. Prior to the APHIS management program, as many as 2,700 cormorants had been counted on the lake per day during the fall migration period, while the adult summer resident population had been as high as 900 birds.
Cornell University research indicated that cormorant predation prior to 1998 was having significant negative impacts on sport fish populations of the lake, including yellow perch and walleye. After control efforts by APHIS were implemented, cormorant use of the lake and associated impacts on walleye and perch populations declined dramatically. The average number of cormorants on the lake during the spring and fall migration period dropped to less than 200 birds per day from 2005-2008, while the resident summer population was consistently less than 150 birds per day.
In 2010 the federal funding was eliminated for the APHIS cormorant management program on Oneida Lake. From 2010-2013, without this federal funding, cormorant management activities on Oneida Lake was undertaken by the New York State DEC (DEC) along with a group of citizen volunteers. Starting in 2014, the citizen volunteer program was phased out and management activities are now undertaken solely by DEC.
2019 Cormorant Hazing Program
The DEC double-crested cormorant (DCC) hazing program was implemented on Oneida Lake starting on April 30, and ran through October 30, 2019. DEC Fish and Wildlife (F&W) staff from both Regions 6 and 7 were involved. The management goal of the program is to keep the resident population of DCC at Oneida Lake during the spring and summer period (April through July) to around 100 birds and to minimize DCC numbers during the fall migratory period. Pyro-techniques are used to haze the DCC with the intent of discouraging their use of the lake. In addition to the hazing efforts, F&W staff collected DCC on the lake, under permit from the U.S. Fish and Wildlife Service, in support of an ongoing diet study conducted by Cornell researchers.
For the 2019 season a total of 17,990 DCC were counted with an average of 562 per trip. The average count per trip for the spring and summer period were 220 and 75 birds, respectively. The maximum count of 1,358 took place on October 8, 2019 during the migratory period. The migratory period typically runs from August through early-October and during that time hazing efforts are increased from one day per week to two or three outing/week. The average count for the 2018 migratory period was 853 per trip.
A total of 206 DCC were collected and examined by Cornell University for diet analysis. When looking at diet composition by numbers of fish, round goby (25%), gizzard shad (37%) and yellow perch (17%) were a significant portion of the diet. However, when looking at diet composition by weight, both yellow perch (34%) and walleye (30%), along with gizzard shad (13%) and round goby (10%) made up a significant portion of the diet. We will continue to collect DCC for this ongoing diet study in 2020.
