EcoMyths: Effect of Global Warming on freshwater fish

November 25, 2013

Kate Sackman

(AP Photo/Lisa Poole)
Bill Brown, of Gloucester, Mass., fishes with his grandson Kai Conti, 6, of Tigard, Ore.

Let’s Get Reel: Warmer Lakes and Streams Devastate Freshwater Fish

If you had wonderful, lazy days fishing at the lake with your grandpa, you would bait the hook, reel in a couple of good sized perch, and bring them back for Grandma to cook.  Those days are under threat now, and not just because of our obsession with Twitter and Angry Birds Star Wars.

We’ve all heard about many changes due to of global warming like melting glaciers and unstable, unpredictable weather. But did you know it also affects freshwater fish? Today, Jerome and I talked with National Wildlife Federation spokesperson Frank Szollosi, M.S. to find out why some of our favorite fish species are declining or under threat.Recreational fishing is a big industry with $26 billion spent by consumers every year, according to a newly released study on freshwater fish by the National Wildlife Federation. Climate change is warming water to the point that cold-water fish species are not only driven north, but are dying. Frank told us that fish species are grouped into three different types of species: cold water, cool water, and warm water fish. Cold water fish become very vulnerable with increasing temperatures, making fish more susceptible to “pollution, parasites, and disease” according to the study. Species that are unable to migrate to colder, more hospitable waters often fail to reproduce in their native habitat and the populations die out.

Warmer air temperatures cause increased water temperatures, Frank says. In addition, warm air causes greater evaporation and can lower water levels, resulting in warmer water. Pollution also compounds the impact of warming waters. In the Great Lakes, the western basin of Lake Erie has a significant problem with enormous algae blooms that deplete oxygen from the water, making the water uninhabitable for fish.

Climate Change will accelerate unless we cut our carbon footprints. Frank reminded us that we can make small daily choices that add up. Easy energy efficient changes at home can make a difference, like lowering the thermostat a few degrees in the winter and switching out some of your light bulbs for fluorescents or LEDs. It may not seem like much, but when thousands of us cut our energy usage, we cut down global-warming producing carbon into the atmosphere. Frank gave us hope, but also made it clear that we have to play our part to ensure we don’t lose precious fish species in the wild.

Learn more about this myth! Listen to the podcast of today’s show or go to the EcoMyths Alliance website to learn more about global warming impacts on freshwater fish.