Vermont's Fish Health Program
A Fish Health Program in Vermont? You Bet!
Vermont’s two state Fish Health Biologists focus entirely on the health of both hatchery-raised fish and wild fish. Every day, they work to prevent and manage serious fish diseases so the people of Vermont can enjoy healthy fish populations. Searching for the cause of fish health problems is like playing detective, looking for clues to determine what could be negatively affecting or outright killing fish.
What might these clues be? Here’s an example of the type of work a Fish Health Biologist does day-to-day, both for wild and cultured fish environments:
Maintaining Fish Culture Health: A Story
One spring morning, a Fish Culture Station Manager became concerned with a group of brook trout and alerted us. The manager explains this group of trout had been thriving, but has started to reduce feeding, and some of the young trout are gathering at the water inlet. After a short road trip, we meet with the hatchery staff to observe the trout and discuss a variety of factors that might be causing this situation. We collect a few trout and transport them back to the Fish Health Laboratory at the Vermont Agriculture Environmental Laboratory in Randolph Center. This facility is equipped with state-of-the-art laboratory instruments with molecular capabilities to help identify the problem. Using a high-powered microscope and special stains, a common bacterium was detected on the gills of the fish. An approved chemical treatment was quickly administered, and fish loss was avoided.
About Wild Fish Health
When investigating fish health issues in the natural environment, we will work with fish biologists, game wardens, environmental enforcement officers, and other aquatic scientists to assess the situation and find a cause. Many times, a report comes in that a large number of dead fish have been observed. Such “fish kills” can occur for a variety of reasons, including oxygen depletion, lightning strikes, stress, viral, parasitic, or bacterial infections, and accidental or purposeful release of chemicals to the natural environment. These factors can cause varying degrees of fish loss and impact fish populations. A collaborative approach is essential to accurately identify causes and protect aquatic ecosystems
Gyrodactylus, a flatworm parasite, viewed under a microscope.
As Figure 1 demonstrates, it is useful to think of fish disease or fish health as a set of interactions among the host (fish), the fish pathogen and the environment. Diseases can have major impacts on Vermont’s fish culture stations, stocking programs and natural fish populations. Luckily, Vermont’s fish health biologists continue to monitor and help keep our fish populations swimming.
