Monday, June 22, 2009

Fishing and Climate Change

Is the Big Wood destined to become a bass river? Will salmon conservation efforts in Idaho soon be rendered moot, because rivers are too warm for coldwater fish? Will New Zealand mud snails in Silver Creek--present but not problematic--suddenly erupt and overtake the whole watershed?

We don't have the answers to these questions, but one thing is certain: Climate change is poised to have profound impacts on native fishes--and fishing.

That was the message delivered by renowned fisheries biologists John Casselman and Jim Martin at last week's Outdoor Writers Association of America conference.

Casselman, a professor of biology at Queen's University in Ontario, has studied impacts of climate change on Great Lakes fish species. He found that even a one-degree increase in temperature can have profound impacts on fish populations. In some lakes warmwater species of fish like smallmouth bass have increased 60%, while coldwater species have decreased 60%. In some lakes, coldwater species have disappeared entirely.

Black crappies are expanding in many lakes, preying on walleyes. And his studies mirror what is being found by fisheries biologists across the country.

"Fish are very sensitive indicators of climate change and are responding," Casselman says. "We should accept that climate and temperature are driving factors affecting fish production and manage accordingly.

Martin, the new chair of the Theodore Roosevelt Conservation Partnership, sees this as an opportunity rather than an obstacle.

"In my forty year career as a biologist, I've seen the attitude toward climate change go from denial to depression," he says. "But depression is a paralyzing condition. We need to move forward with energy and excitement and hope. This is the best time in history to be a conservationist."

Martin sees anglers playing an important role in solving the climate change problem. If they haven't seen the impacts on their favorite waters already, they will soon, and he hopes it mobilizes them into action.

"There are going to be a lot of surprises in the new century but we're up to it," he says.

To read more about the effects of climate change on fishing and hunting, check out the excellent new web site, Seasons' End.--Matt Miller

1 comment:

Anonymous said...

Natural cycles have the capability to increase temperature by amounts that will have an effect on any number of plant and animal species. Over the history of the planet, species have come and gone as a result of natural processes that affect and change the climate.

Why do we now attribute our changing climate to the effects of manmade CO2 emissions? What we are now observing has to be more of ongoing natural processes, albeit with SOME effects of humans. Why are you so certain that manmade CO2 has selectively chosen your location for warming? Other locations have seen cooling, despite ever-increasing CO2 in the atmosphere. Overall, global temperatures have remained steady or have slightly cooled during the past decade.

To my way of thinking, man's effect on the environment has been more pronounced by land use practices, wildlife management, and conservation measures gone awry.