Early numbers show some trout mortality from freezing temperatures
The colder-than-normal weather the Lowcountry experienced earlier this year has adversely affected South Carolina's spotted seatrout population, but how problematic that will be for saltwater anglers remains to be determined.
Steve Arnott, with the Inshore Fisheries Section of the Marine Resources Research Institute, said there were a dozen reports of fish kills all the way from Port Royal Sound to Little River on the border with North Carolina. In addition to trout, he said there were reports of dead red drum (redfish) in the Georgetown area as well as dead mullet in the Little River area.
The S.C. Department of Natural Resources does monthly trammel net surveys to sample fish populations in seven different areas along coastal South Carolina as well as quarterly surveys in some other areas.
"The last couple of years we have seen seatrout numbers rebound in response to normal winters," Arnott said, but the numbers from surveys done since the temperatures dropped the water temperatures into the danger range have shown a decline.
"You are looking at a moving target. We still don't know the full extent of what has occurred. If you look at the long-term average over the last 10 years or so, we've started to dip just below that 10-year average so that means the population is lower. But seatrout is a species that has naturally large fluctuations in size, mainly in response to winter conditions. So this is in line with expectations.
"The winter event does seem to be taking its toll, but we have to see what happens over the next several months."
It took trout five years to fully recover from a cold-related kill in 2001. And in the spring of 2011 the Department of Natural Resources asked fishermen to voluntarily practice catch and release of trout until fall of that year to protect the remaining spawning fish after back-to-back cold winters.
"Two things affect (the fish mortality). How cold it gets and how long it gets cold," Arnott said earlier this year. The temperatures preceding the polar vortex and the days afterward have been relatively warm and that provides hope, he added.
Arnott said the trout numbers in recent surveys reflect what biologists would expect from a historical perspective.
"We have seen more dramatic events in the past," he said. "So far, not by any means was this the most extreme weather event we've seen. The most extreme was 2000-01 where we went from a very high population to very low, very dramatic numbers."
The catch limit for trout is 10 per day and the fish must be 14 inches total length. There is no closure or voluntary restriction now and there may not be. But it might be a good idea if anglers would practice catch and release with trout until we know for certain there aren't going to be any issues.