Heat and drought impacting cooperative trout nurseries in Pennsylvania
Pennsylvania Fish & Boat Commission cooperative trout nurseries are in weather-related trouble, and this summer’s extended heat and dry weather will mean fewer trout stocked next spring.
A recent September morning trip to feed the trout at my local Pennsylvania Fish & Boat Commission cooperative trout nursery was very discouraging. I am one of 15 or so volunteer feeders at the Bald Eagle Sportsmen Club’s co-op. Each year we raise 35,000-50,000 trout, which are stocked in streams in a three-county area.
Raising trout is a lot of work and my efforts are only a small part of the big picture. I feed the trout, clean the screens and remove any dead trout one morning a week. I also assist on stocking days and sometimes with special nursery-related projects.
This particular morning was very discouraging. I filled my trout food buckets and headed to the raceways. I found a lot of “white” – dozens of dead trout covering the bottom of the concrete raceway and many more floating and backed up against the screen covering the outflow.
I netted out over 100 dead trout, 10-16 inches long, from one raceway. Many more trout that I could not reach littered the bottom. In another raceway, I collected over 50 dead brook and brown trout fingerlings. Given the right conditions and food, these fingerling trout would have been 9-12 inches long by April 2017.
A sudden disease, a water-flow blockage or a malfunction of the aeration system was not the problem. According to the nursery manager, it was just the cumulative stress to too many hot days, warm nights and too low flows of fresh water into the cooperative nursery.
Trout grow best in water temperatures in the 50s and low 60s. Cold water also is able to hold more dissolved oxygen, with trout needing at least 5 parts per million. Higher water temperatures decrease dissolved oxygen and make it easier for diseases and trout parasites to flourish. Low flows of clean water only serve to exasperate the problem.
Fortunately, cooler nights made my last week feeding trip to the co-op more pleasant. I collected only 10 dead trout. However, recent high temperatures are still in the 80s and unfortunately, drought relief is not in sight.
I couldn’t help but think of how many limits of nice trout were wasted. The problem is not just with the Bald Eagle Sportsmen’s Club, either. Many of the 160 cooperative trout nurseries all across the state are having weather-related difficulties. Together, the co-ops raise about 1 million trout. With the coops accounting for approximately 25 percent of all trout stocked, expect fewer trout to be stocked and caught next spring.