Written by Vic DiCenzo, PhD, Fisheries Biologist
Whether you use your lake or pond for boating, bird watching or fishing, everyone can agree that they desire a healthy waterbody, especially one with healthy fish. But what constitutes a healthy fishery? What signs would indicate that a fishery is unhealthy and what approaches could improve an impaired fishery? The health of a fishery can be interpreted in several ways, and the recommended management approaches may vary depending on your ultimate goals.
Goal: A Balanced Fishery
Fisheries managers often describe a healthy fishery as one in which the predator-prey ratios are balanced. This assumes that a sufficient amount of prey (Bluegill, Shad, Shiners, etc.) exist to support predators (often Largemouth Bass) so that they maintain adequate size, growth and condition. Indicators that suggest a fishery is unbalanced could include high catch rates of small fish, a reduction in the maximum size of fish caught or fish that appear significantly underweight.
The first step to achieving a balanced fishery is an assessment of the water quality as well as the fishery. At SOLitude, we utilize professional water quality testing and in-house, state-of-the-art laboratory analysis to determine all aspects of water quality. An electrofishing survey allows us to collect fish population data to assess the current state of your fishery and health of your fish. Based on results, improvement strategies may include vegetation management, habitat improvements, fish stocking, fish feeding and selective harvest of predators.
Goal: Absence of Fish Disease
The most common way to classify fish as healthy is if they are alive and free of disease. Generally, it’s easier to prevent disease rather than treat it. Fisheries biologists prevent disease through water quality management, providing suitable habitat, maintaining fish abundance at appropriate levels and requiring that any fish introductions come from a disease-free source.
Signs that could indicate unhealthy fish include open sores, lesions and skin discoloration, as well as signs of stress which could be indicated when fish swim near the surface or shoreline. Depending on the cause and severity of the fish health issue, a variety of approaches can help improve the situation including restocking healthy fish, implementing a harvest plan to avoid overcrowding, managing nutrients and algae in the waterbody, improving water quality through aeration and maintaining proper amounts of desired aquatic vegetation.
Goal: Fish that are Safe to Eat
While most U.S. waters do not contain dangerous levels of contaminants, some waters and fish may cause concern. Contaminants such as mercury, polychlorinated biphenyls (PCB’s) and Kepone are the most common in U.S. waters and are monitored by governmental agencies to protect the public from exposure. Contaminant levels in private waters are not as well understood, which is why routine water quality testing and monitoring are highly recommended. Reducing contaminant levels before consumption can be done through removing skin and fat, then cooking it on a grill or rack, allowing fat to drip away.
A healthy fishery can mean different things to different people. But despite your definition, assuring that you have a healthy fishery requires a basic understanding of your pond’s water quality and fish community to identify factors that could improve overall fish health.
Contact the experts at 888-480-LAKE (5253) for all of your lake, stormwater pond, wetland and fisheries management needs.
Vic DiCenzo, PhD, is a fisheries biologist experienced in the design and implementation of studies that collect fisheries data from lakes and ponds. He uses this information to make recommendations to clients for the long-term management of their aquatic resources. He takes a quantitative approach to fisheries management, often estimating rates of recruitment, growth, and mortality and uses these rates to simulate populations under various management strategies. Vic received his PhD from Virginia Tech in May 2016.
SOLitude Lake Management is a nationwide environmental firm committed to providing sustainable solutions that improve water quality, enhance beauty, preserve natural resources and reduce our environmental footprint. SOLitude’s team of aquatic resource management professionals specializes in the development and execution of customized lake, stormwater pond, wetland and fisheries management programs that include water quality testing and restoration, nutrient remediation, algae and aquatic weed control, installation and maintenance of fountains and aeration systems, bathymetry, shoreline erosion restoration, mechanical harvesting and hydro-raking, lake vegetation studies, biological assessments, habitat evaluations, and invasive species management. Services and educational resources are available to clients nationwide, including homeowners associations, multi-family and apartment communities, golf courses, commercial developments, ranches, private landowners, reservoirs, recreational and public lakes, municipalities, drinking water authorities, parks, and state and federal agencies. SOLitude Lake Management is a proud member of the Rentokil Steritech family of companies in North America.