Fish these Lafitte hotspots in March, and your arm will feel like you just spent six hours on your Bowflex.
Television viewers from the 1970s will easily remember the irate words, “It’s not nice to fool Mother Nature,” followed by a peal of thunder and a bolt of lightning. That was a matronly, daisy-bedecked Mother Nature’s (played by Dena Dietrich) response to being informed that the Chiffon margarine she just tasted was indeed margarine and not butter.Humans have tried fooling Mother Nature probably as far back as when the first caveman fashioned a cudgel to go hunting for supper. Modern humans, convinced of their mastery of nature have extended the notion of fooling Mother Nature to benevolently “helping her out.”
Hunters and fishermen treasure healthy (read large) stocks of fish and wildlife. Confident both that modern Mother Nature has one arm tied behind her back and that science and technology can mass-produce anything, a lot of well-intended sportsmen have placed great faith in the curative powers of stocking fish.
Logic only dictates that when fish are pumped into one end of a system, more fish will come out of the other end. Right?
One of the situations that would seem to scream for human help is in the aftermath of a catastrophic environmental event, such as a hurricane. Cyclonic storms such as Hurricanes Andrew in 1992, Georges in 1998, Katrina and Rita in 2005 and Gustav in 2008 left massive kills of freshwater fish in their wakes.
What seem to be millions of rotting fish floating on the surface of putrid water the color of ink are enough to make any caring angler question if the resource can recover without help. Yet case study after case study shows that it does and, in fact, fish numbers in recovery often surge past what they were before the catastrophe — without restrictive changes in creel or minimum size limits, without harvest closures and without stocking.
A recently released post-Hurricane Rita report by Louisiana Department of Wildlife and Fisheries (LDWF) biologists Bobby Reed, Eric Shanks, Paul Smith and Joe West clearly shows how resilient fisheries resources can be.
On Sept. 24, 2005, Rita roared ashore near Johnson’s Bayou in Cameron Parish with 150-mph winds. Its 20-foot storm surge caused fish kills from Vermilion Bay to Sabine Lake and as far as 60 miles inland. Salt water in the surge killed many freshwater fish quickly.
Worse, the storm killed vast amounts of freshwater plants, and churned up organic debris into the water column. In the tropical heat following the storm, the rotting vegetation quickly stripped the water of all oxygen. Drought conditions followed the storm, preventing any flushing of saline and deoxygenated waters.
The watersheds of three southwestern Louisiana rivers, the Calcasieu, the Mermentau and the Sabine, were dramatically affected. LDWF biologists began sampling both the habitat conditions and the fish populations of the three river systems by three weeks after the storm. The results were depressing.
In the Sabine River, the least affected of the three systems, oxygen levels and salinities had returned to normal by three weeks after the storm. But when they sampled the fish populations, they found zilch, zero, nada largemouth or spotted bass, not just in the fall of 2005 but even in the spring of 2006.
In the Calcasieu River, oxygen levels returned to normal at two sampling areas by week four after the storm, but not until nine weeks was it normal throughout the system. Salinities did not return to normal until 14 weeks after the storm.
Fish sampling with electrofishing (shocking) equipment in the fall of 2005 failed to produce a single fish of any species. Spring 2006 sampling produced a grand total of three fish, one largemouth bass, one bluegill and one channel catfish.
The Mermentau River had the poorest conditions. Most sampling stations had very low oxygen levels 10 weeks after the storm. The storm surge pushed higher than normal salinities as far inland as the Lacassine Refuge Headwaters. Salinities remained elevated in the Lacassine Refuge Pool until the return of rains in week 13 after the storm.
Because of the poor conditions, no fish sampling was done in the Mermentau in fall 2005. Spring 2006 sampling yielded few fish. Nothing in the bass/bluegill/crappie or minnow families was found, and even bowfin (choupique) and garfish were scarce. The numbers of fish in the Mermentau samples indicated an almost complete wipe-out. Some bass survival did occur in the Laccasine Refuge Pool, however.
No fish were stocked in the Sabine and Mermentau systems, and only a token stocking of 13,500 largemouth bass was made in the Calcasieu River. The outlook was grim to many anglers.
But a funny thing happened on the way to the morgue. The fish population recovered — with a vengeance. In the Sabine River, the number of bass caught per hour of shocking, called “catch per unit of effort,” or CPUE, had by the fall of 2006 bounced up to twice what it had been in the best years of 1997-99, well before the storm.
By fall 2007, the numbers were four times higher than what they had been in 1997-99. And not a bass had been stocked; nor had a size limit been put in place; nor had the creel limit been reduced.
Calcasieu River showed a similar pattern. By fall 2006, the CPUE of bass was more than twice the long-term average. By fall 2007, it was three times higher than the long-term average.
The Mermentau River, long challenged by water quality problems from sedimentation and
fertilizer run-off from rice fields in the watershed, did not show as clear a pattern of recovery. Still, from no bass found after the storm, populations had recovered to the long-term average by fall 2006. Then bass numbers declined to half that one year later.
Lacassine was a special case. In its report, the LDWF described the recovery of the bass population in the Lacassine Pool as “phenomenal.” By winter 2008, largemouth bass populations were five times higher than the long-term average. Some older and larger bass were in the samples, so some fish had survived the storm surge, but most of the numbers were post-storm fish.
The report concludes, “When predators and competition are temporarily eliminated due to some catastrophic event, fisheries recruitment and growth rates exhibit vigor and plasticity. Again nature shows us that no ecological niche will remain unfilled for long.”
Does this mean that stocking should never be considered after a catastrophe?
“No,” says Gary Tilyou, LDWF Inland Fisheries Division administrator. “If an area is totally decimated and there is no way for natural repopulation by water connection, we would restock.”
When pressed, Tilyou admitted he couldn’t think of such a case in Louisiana, but maintained that it was possible.
“Nature typically contributes far more to a fish recovery than we do after a big kill,” he said. “For example, after Hurricane Andrew nature contributed this much (hands spread all the way apart), and we contributed about this much (the fingers on one hand spread an inch apart). It doesn’t take many brood fish to repopulate an area.
“In most cases, we do not need to restock after natural disasters, no matter how bad it looks on the surface. People see what died and is floating on the surface. We (LDWF) evaluate what survived, not just what died.”
What survives dictates the need for stocking, not what dies, he explained.
“A lot of people misunderstand stocking,” Tilyou said. “They think stocking will cure something not caused by a lack of fish. Stocking on top of an existing population is worthless because (habitat) conditions determine the carrying capacity. If fishing is poor in an area, it’s probably due to a habitat problem.”
After Hurricane Gustav caused a large fish kill in the Atchafalaya Basin in 2008, concerned sportsmen discussed what to do to restore the Basin’s bass population. The heroic-sounding statement, “Doing nothing is not an option,” was tossed around a good bit. Yet science tells us that doing nothing sometimes is not only an option, but is the best option.
Jerald Horst is a retired Louisiana State University fisheries biologist. He is currently active as an outdoor writer, occasionally reaching back into his former profession to do interpretive articles on fisheries issues.
