Fisheries Biologists Speak Out on Smoky Mountain Drought and Trout

By now it’s no secret that the Smoky Mountains have experienced one of the worst droughts in recorded history. Water levels in Little River have been at or below record flows since spring. Fishing was tougher than usual but things got pretty grim in August when East Tennessee also experienced record high temperatures. Recent rains and cooler weather have brought improvements but the water is still low. Many local fishermen have been exceptionally pessimistic, but we see reasons for optimism.

First of all, we check the river several times every week even if we’re not guiding. We can say from first hand experience that there are still plenty of trout in Little River. We even know the location of several 18-20” browns which have pulled through the heat. Brook trout fishing in many high elevation streams remained excellent. That was where we did much of our fishing in the Smokies in August.

Charity and I have participated in a number of fisheries projects in the park over the years and have a good relationship with the biologists who work there. Charity contacted park fisheries and we’d like to share the response we got from Matt Kulp.

The park is NOT advocating for anyone to refrain from fishing; most of that has been from fishing guides. Yes, high summer temperatures do stress trout, that’s what limits their southern distribution. Yes, temperatures in the upper 70’s are tough on all trout species, especially for extended periods of time (>7 days) such as we’ve seen this summer. Rainbow and brown can tolerate temps up to 24-26C (75-79F) for short periods of time. However, keep in mind, what you’re really focusing on here are rainbow and brown trout (both non-natives) at low to mid elevations (<2,500ft). Natural annual mortality rates of adult rainbow trout are 60-70% a year anyway, so Mother Nature is just fulfilling what would normally happen near the end of their life cycle anyway, just using a drought to do it. If you catch and adult rainbow trout, consider yourself lucky, take him home for dinner, and don't feel bad about it. Monitoring surveys so far this summer indicate trout densities have not changed a great deal, rather juvenile and sub-adult survival has been very good while adult mortality has been higher. So what we're seeing is a composition change as the temps work over the adults. The only fish which may really take it hard are the large brown trout, but that will remain to be see. We don’t really think the full impacts of the drought will be seen until next spring after we get through the fall low flow period and see what winter/spring brings us. In terms of our brook trout, remember, 83% of our brook trout populations are found above 3,000 feet. Water temps there have been higher than normal, but still acceptable for brook trout. In any case, brook trout have adapted to these periodic droughts in the southeast and are well adapted to these low water, high temperature conditions. In fact, during drought years in mixed rainbow/brook trout populations, brook trout reproduction and survival is much greater than rainbow trout, which typically do better in high water years. Finally, lost in all this is the fact that non-game fishes (our true native fishes in these low-elevation cool and warm water environments) are doing quite well. Typically during drought years, we focus on trout and miss the fact that these non-game species have pretty good year classes. So, again, we need to keep it all in perspective. In the big picture, we may lose some large adult fish, but we lose some of these fish each year any way given where they live and the conditions they live in. The only big difference this year may be on big brown trout. And as far as big brown trout go, 95% of the people don't know how to catch them anyway. We may lose some of them at lower elevations, probably already have, but I really doubt any limited fishing pressure they do see will impact them any more than what Mother Nature is dealing them right now. Gotta keep it all in perspective.