Lake Management

Lake Management – Freshwater Fisheries Survey

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Dave, Amy, Charlotte and I are in the process of performing a fish population dynamics study for a client.

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In order to determine if the lake fisheries are in healthy balance, we needed to perform a fish survey.

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The methods used included seining and electro-shocking (Smith & Root Backpack Shocker), within bounded and measured reach sections.

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All fish within study bounds were captured, measured and species determined.

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The species noted included largemouth bass, green sunfish, red-breasted sunfish, bluegill, mosquito fish, various tadpole species and painted turtle.  We had all size classes including adult breeders, fry, fingerlings and year-old’s.

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The lake includes a catch and release recreational fishing component, has two feeder streams, an island, aeration system, a trail network, vegetated shorelines and a series of piers, pedestrian bridges, boardwalks and interpretive displays.

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We are suspicious that the lake may have an imbalance of predator/prey relationship.  We suspect that when larger bass are caught, some may be removed.  This in turn, may allow for an over-abundance of sunfish species.

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I noted that when I electro-shocked areas of over-hanging vegetation and emergent vegetation, our catch number went up.  It’s the old adage that 90% of the fish occupy 10% of the water.  I’ve done a fair amount of pond and stream shocking.  All of the fish are tightly associated with large woody debris, rock outcrops and other forms of structure, occur up and under banks, undercuts and vegetation, not in open water.

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After Dave completes his analytics, we will have recommendations on how to enhance recreational fisheries.  The main analysis tool is known as Proportional Stock Density,  the ratio of bass to bluegill, (where the number of individuals greater than or equal to the minimum quality length, times 100).  Another important tool is “best professional judgement,” as we have done a fair amount of this type of work.

Great day in the field!

 

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