IMPACTS FROM FLOODING FELT ON A DIFFERENT SCALE FOR FISH

While many communities and individuals across Pennsylvania continue to flounder in the wake of devastation wrought by recent flooding, the rushing streams and rivers are little more than an inconvenience for some populations accustomed to water in their homes – fish populations. And although it may be hard to imagine for those of us who witnessed the floodwaters’ power, in terms of catastrophes, finned creatures view recent events on a different scale. For fish it’s simply a matter of adjusting to go with the flow.

As Pennsylvania Fish and Boat Commission biologist Dick Snyder points out, a flood is a natural event and Mother Nature equips her charges to deal with that which comes their way. According to Snyder, high waters may alter aquatic habitat and place stress on fishes, but for the most part the effects are short-term. As the Commission’s Chief of the Division of Fisheries Management, Snyder has witnessed plenty of streams spill over their banks and he has also seen fish populations adapt.

“To a fish, a flood feels much like walking up an alley during a strong windstorm feels to us. And fish react in pretty much the same manner we do; just like we’ll duck into a doorway to get out of the wind, fish will seek out those areas where the force of the water isn’t as great,” said Snyder.

Though some fish may be permanently dislocated during a flood, most manage to take refuge. Areas of refuge can be as simple as a stream bottom where water moves more slowly. Rocks or logs also offer shelter. Additionally, calm eddies out of the torrent provide congregation points for fish to rest – even if the pools are located in areas where they wouldn’t normally be found, such as over a road or in a pasture.

As floodwaters recede, fish will usually find their way back to the usual holding spots, though Snyder noted some may get stranded in puddles and sinkholes if waters recede quickly. Trout may actually benefit from the high water as spawning areas might be scoured clean of silt and sediment. Only time will tell of the impact on American shad returning four or five years from now as the 2004 year class was in the process of migrating to the ocean.

It appears that the floods of 2004 won’t significantly impact the Commission’s stocked trout programs either. Some Commission hatcheries did experience some flooding, most notably the Benner Spring State Fish Hatchery in Centre County. While fish inventory work is ongoing, initially it does not appear there will be any major changes to the trout stocking program.

What many anglers may notice are some physical changes to trout streams and other bodies of water. “Many streams and rivers have been physically altered during the course of the flood,” Snyder pointed out.

“Gravel and rocks have been swept downstream. Stream banks have been washed away and silt has been redeposited in different locations. Some areas that may have been prime fish habitat before are now gone altogether. Other areas that weren’t ideal before may have been scoured and look just great.”

While it will be weeks or months before the experts tabulate a final price tag on disaster damages from water and mud, the bottom line for fisheries is less clear. Said Snyder: “Short of reading about it somewhere, a few years from now it will be nearly impossible for us to tell there was even a flood.” But, what happens the rest of this fall and winter may also have a great impact on fish populations awaiting our enjoyment next spring and summer.

Dan Tredinnick
Press Secretary
PA Fish & Boat Commission