This week, we had Steve Fajfer from the WI DNR Wild Rose Hatchery in to talk with us about the role of fish propagation in fisheries management. Steve is the hatchery supervisor, and he has worked for the DNR most of his life – between 30 and 40 years. He was involved in a huge renovation project of the hatchery which took about 20 years to complete. The hatchery now regularly raises the following species: walleye, northern pike, musky, lake sturgeon, brown trout, Coho & Chinook salmon, and occasionally a few others. Wild Rose is the only hatchery in Wisconsin to raise lake sturgeon. The hatchery consists of different types of tanks to accommodate the habitat needs of each fish, such as netted cool & cold water ponds and indoor raceways. All the funding for the hatchery and its employees comes from fishing license sales, which is pretty neat.
The entire process of raising fish is pretty complicated. Once the eggs are extracted, they are incubated in separate compartments. Millions of eggs are sort through by hand, separating live from dead eggs. Eggs are treated with iodine beforehand to disinfect and minimize pathogens. Different water systems accompany the fish as they grow. For example, they use recirculating water and a heater system for the coolwater fish, and simple gravity flow for coldwater fish. When the fish are moved to outdoor ponds, they are fed minnows so that they grow faster. However, this type of harvest is labor intensive and minnows are vectors for many diseases, so this may also harm the fish. Species are released into lakes and streams at various times depending on their ideal stock size. This is a pretty broad outline of the process, and it is important nothing goes wrong – fish are seasonal breeders, meaning they can’t ‘start over’ with a year class if it isn’t raised properly.