Electroshocking Fish: In-Seine? No. Safe, Educational? Yes. (Day 3)

July 27, 2010



Olcott, or Olcott Beach (pictured in (1) above] as the locals in this lakeside Niagara County hamlet refer to it, is home to the deepest harbor (2) on Lake Ontario west of Rochester. On this day, another sign should be posted, though. One reading, “no fish were harmed during the making of this demonstration.” We’re here with U.S. Fish and Wildlife Service (USFWS) biologists Mike Goehle and Denise Clay for a truly interactive fish biology lesson. The pair use equipment aboard their small metal boat (4) (5) to electroshock some fish swimming in Eighteen Mile Creek. The fish – which are temporarily stunned so they can be captured for monitoring – were placed in a cooler, identified for our group of teachers (3), and then all safely released back into the Creek.

Eighteen Mile Creek is one of around 40 Areas of Concern (AOC) in the Great Lakes (click here for related resources). Nearly a decade after the revised 1978 Great Lakes Water Quality Agreement was signed by Canada and the United States to “restore and maintain the chemical, physical, and biological integrity of the waters of the Great Lakes Basin Ecosystem,” the two nations agreed that the worst areas would be given priority attention. Subsequently, 43 such areas were designated as Areas of Concern because they contained contaminated sediment, inadequately treated wastewater, nonpoint source pollution, inland contaminated sites or degraded habitat to a greater degree than the rest of the Great Lakes. Twenty-six of these are solely in the United States, 10 are solely in Canada, and five are binational waterways. Some of the other AOCs in the Lake Ontario region include the Niagara River, St. Lawrence River, and the Rochester Embayment; the Oswego River is one of three AOCs delisted over the years, meaning it is no longer of concern.



Some of the specimens caught during the experiment included: bowfin (6) (9), largemouth bass (7) (10) and pumpkinseed sunfish (8). Adult largemouth bass average 1-2 pounds and 10-15 inches, but can grow to over 20 inches and nearly 10 pounds. They prefer rocky or gravel bottoms, feed on insects, crayfish and small fishes, and spawn in late spring. Pumpkinseeds, which prefer shallow water with some weed cover, reach a maximum length of about 16 inches, although sizes of 6-8 inches are more typical. As for the bowfin, it, along with gar and sturgeon, are among the few freshwater fish still in existence that were contemporaries of the dinosaurs. When the oxygen level is low (as often happens in still waters), the bowfin can rise to the surface and gulp air into its swim bladder, which is lined with blood vessels and can serve as a lung.




The invasive round goby (11) was first discovered in the St. Clair River, the channel connecting Lake Huron and Lake St. Clair, in 1990. The species, which displaces native fish and can spawn multiple times a year, comes from the same area of the world as the zebra mussel (around the Black and Caspian Seas). Presumably, they arrived the same way as the zebra mussels, too: in ballast water discharged by transoceanic vessels.


The white sucker (12) is a very common bottom-feeding freshwater fish that will eat almost anything it can, but most commonly small invertebrates and plant matter. Larger predatory fish species such as walleye, trout, bass, northern pike, catfish, and muskellunge prey on the white sucker. This species is usually not fished for food, though some consider it good to eat. It is most often used as bait; the young are sold as sucker minnows.




Following the demonstration, Goehle used some water sampling equipment - a plankton net (13) and hydrolab (15) to, respectively, collect plankton and larval fish [examined by teachers in a plastic container, (14)] and run some standard tests (pH, turbidity, water temperature, and dissolved oxygen).


Some plant specimen were collected from the Creek as well, including the native Vallisneria, or water celery (16) and two very similar species - the invasive Eurasian milfoil and the native coontail, as displayed by New York Sea Grant’s (NYSG) Helen Domske (17).


In a two-year NYSG-funded study that wrapped up late last year, University at Buffalo investigator Joe Atkinson [pictured in green, (18)] and his team created a web-based tool that allows scientists and managers to plot a resource shed for Lake Ontario or Lake Erie at any location of interest. After undergoing testing off-and-on for about a year, Atkinson said, “This tool will be able to plot resource sheds not only for the long-term average hydrodynamic conditions originally proposed but also for a set of historic conditions, for years since about 2000.” His team’s findings were published earlier this year in an Environmental Science and Technology journal article. “Our goal was to develop the concept of resource sheds to help users better understand the large scale physical processes that are the forcing factors that underlie many important Great Lakes issues, such as hypoxic [low dissolved oxygen] zones, contamination spread, population declines and disease outbreaks.”


Buffalo State College Biologist Dr. Randy Snyder is the project leader for a two-year NYSG project designed to improve understanding and accurate forecasting of the condition and growth of alewives (19), an important component of the Great Lakes food web. “They are a great forage fish for Lake Ontario’s salmon population,” he said, “but unfortunately, that’s based on both an invasive (alewife) and an introduced, stocked species (Pacific salmon).”

Snyder is evaluating how lake temperature, ration size and prey composition influence alewife growth and condition. Given the dramatic changes occurring in the Great Lakes food webs, development of accurate measures of alewife condition and growth will improve fisheries managers’ ability to optimize salmonine stocking rates, forecast how changes in food webs or abiotic factors will affect alewife populations, and better predict the impact of alewives on their prey populations.



After Snyder’s talk, the teachers were introduced to graduate students [including Kevin Cudney, in white, (20)] working with SUNY College at Buffalo Biologist Dr. Christopher M. Pennuto. Pennuto is the project leader for a two-year NYSG project on the round goby that was completed late last year. The exotic goby has had a significant impact in the Great Lakes and is expanding its range. There is concern over its ecological impact to tributary streams and how readily the goby will expand upstream. “Our assessment of round goby swimming performance should enable us to collaborate with engineers in developing fish passage designs,” says Pennuto.

Snyder [in the green t-shirt (22) rejoined the teachers for some seining on the Niagara River (21). Seine nets are usually long flat, weighted nets that hang vertically in the water and are used to encircle, and safely collect, fish for study.

Some of the specimen collected during the activity included: quagga and zebra mussels [in, respectively, the left and right hands (23)], juvenile rock bass (24), juvenile gar (25), red horse sucker (26), smallmouth bass (27), and white sucker (28). “Seining in the Niagara River was a great experience,” said Erik Bauerlein, a teacher from Hamburg, NY. “We netted a gar, which I didn’t know existed in the Great Lakes. It was equally interesting to electroshocking, when we observed other species of fish I was also unfamilar with, including the bowfin.”




The teachers returned to the Buffalo State College Field Station once the fish were properly identified and either released back into the River or collected in coolers for further study. At the field station, the teachers were greeted by Bill Wippert, a photographer for the Buffalo News. Wippert snapped several photos, including ones while the teachers were cleaning off the gear and examining their fish-laden cooler (29). For more, see the Buffalo News article.


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