
One of the constant threats to brookies brought up by fisheries officials and TU members on this trip was global warming. There was not necessarily a consensus about how much warming has or will take place, but most agreed that temperature increases have taken place and rainfall is less consistent, more flashy.
Now that I am back in the Deep South, the heat has inspired a post about global warming.
Fish found in spring-fed headwater streams fair well in normal drought situations. They are fed by cold, underground sources. But for headwater streams to remain perennial versus ephemeral, rain and snow has to recharge these watersheds. And today in the Deep South, the recent drought has alarmed many because rainfall has significantly decreased. States such as Georgia, North Carolina and eastern Tennessee have all been in drought conditions over the past several years. All one has to do is visit a reservoir in northern Georgia and take a look at lake levels to understand how bad the drought has been.
Brook trout are resilient, but as stream flows decrease, fish will be lost even in cold headwater streams because fish obviously need a minimum flow to survive tough years. Smaller pieces of water can heat up more quickly during hot summer days. It it not yet known how significant this drought will be regarding brook trout range in the South, but if this current pattern of heat and lack of rainfall isn't broken, the prognosis isn't good for some streams at the southern edge of the brookies range.