Over the past 20 years, the food web in Lake Ontario has changed in response to invasive species and decreased nutrient input. Prey fish like the rainbow smelt have declined, while new species like the round goby have invaded and increased in the diet of predators. The DEC, in collaboration with the US Geological Survey, is conducting a nutritional study to compare 2020 results with previous work from 1999, 2006, 2008 and 2013.
The study is based on using gastric samples of the entire digestive tract from anglers-collected salmon, trout, pikeperch and perch to determine the current species and size composition of the predator fish diet in Lake Ontario and see if they compare to previous studies.
For example, the study will investigate whether salmonids consume less alewife, more gastrointestinal fish and goby or whether predators consume different sized prey than in the past. The stomachs of salmon, trout, pikeperch and perch collected by anglers provide critical data that links important sport fish to the food web.
A network of freezers has been set up around the lake where anglers can drop off samples. The freezers will also contain data cards and zip lock bags.
One may wonder what exactly does such a study mean, especially from an angler’s perspective? Well, here are the procedures that you need to follow and hopefully clear up any questions.
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The study looks for stomachs (digestive tracts) of all sizes and types of salmon and trout, walleye and perch. Collections must be limited to legally sized fish and volunteers must not exceed daily gate limits.
The DEC provides anglers with “stomach data cards” and Ziploc bags. Each removed stomach should be placed in its own bag with a completed “stomach data card”. Please only use pencils to fill out the card. Data cards and bags are located in sample drop-in freezers.
Save stomachs from all the fish you harvest in a day – no matter how “full” or “empty” they appear. Empty stomachs are important data and can actually contain prey fish bones. Please only put one sample and one label in each bag.
Save the entire digestive tract. Cut the digestive tract as close to the gills as possible and as close to the opening as possible. Put the digestive tract and stomach data card in the pocket. Make sure all food goes into the ziplock bag – even if your stomach gets nicked during cleaning.
Record the following information on the stomach data card: name of the angler (optional), date, port you fished from, type and total length (measured if possible).
If possible, keep the sample bag on ice and freeze it as soon as possible.
The DEC plans to take samples from freezers once a week. Please call Mike Connerton at 315-654-2147 if the freezer is nearly full, malfunctioning, or if you have any questions.
Six deep-freeze stations are currently in operation for dispensing. The locations are as follows (general location followed by detailed latitude / longitude coordinates of the exact location of the freezer which can be entered directly into a map app or GPS device):
Purification Station at Fort Niagara State Park (43.260500-79.058350)
Wilson – Bootleggers Marina (43.313667-78.841972)
Olcott – Town of Newfane Marina Cleaning Station (43.336282-78.717636)
Rochester – Shumway Marina Gas Dock (43.251741-77.608563)
Fairhaven – Bayside Marina Cleaning Station (43.314825-76.718921)
Oswego – US Geological Survey, 17 Lake Street (43.462620-76.51709)
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