Colder winters could help fall flounder run
They still appear in the traditional places during autumn, especially in November just after a forreal cold front pushes off the Texas coast bringing a brisk northerly wind that drops temperature and tides, triggering travel driven by instinct and nature’s cues.
Clots of anglers with clusters of rods and reels, their bait buckets holding mud minnows or finger mullet, stream to places such as Rollover Pass, Sea Wolf Park, Galveston Channel, the tip of Bolivar Peninsula, San Luis Pass and dozens of other spots along shorelines and the flats and edges of channels and the mouths of bayous and drains in the lower reaches of bay systems along the upper and middle Texas coast.
They are drawn to these places by another gathering — a migration, really — passing unseen but certainly not unnoticed along generations-old routes beneath the cooling bay waters. Flounder — southern flounder, the instantly recognizable flatfish coveted for its firm, sweet, white flesh that turns oh-so-flaky when baked, broiled, grilled or fried — are on the move.
Not what it used to be
The fall flounder “run” — the mass migration of adult flounder from the bays to the Gulf of Mexico — is as old as the fish themselves. And the gathering of anglers bent on intercepting them has occurred for as long as humans have lived on the Texas coast.
But both are shadows of what they were barely a generation ago.
Texas’ flounder fishery, while still viable and in no immediate danger of vanishing, is struggling and has been for at least three decades. And despite recent upticks in the flounder population and a couple of years of encouragingly good years of flounder-fishing success, the situation remains one of concern among anglers and fisheries managers.
Empirical evidence of what has been a sobering decline in Texas’ flounder population is seen in the 34 years of data collected through Texas Parks and Wildlife Department’s standardized monitoring of coastal fisheries.
Between 1982 and 2008, the relative abundance of southern flounder in Texas waters declined by 50 percent. That decline applied to both the adult flounder population monitored through TPWD’s twice-annual gill-net sampling program and the number of juvenile flounder seen in the agency’s bag-seine samplings.
It also was seen in data on how many flounder Texas anglers landed per hour they spent fishing, as tracked by TPWD through its creel survey program. That number, like the numbers of adult flounder collected in gill nets and juvenile flounder in bag seines, slowly and steadily declined until, in 2010, it fell to its lowest on record.
The steady decline in flounder occurred as the same sampling programs showed long-term populations trends of other marine fish such as speckled trout, redfish and black drum were, at worst, stable or in almost all cases increasing. Some species such as redfish were exploding. And this spring’s gill net sampling saw some Texas bays record the highest catches of speckled trout since such sampling began in the 1970s.
The anomaly of flounder declining while almost all of Texas’ other inshore fish were holding their own or better appears to be connected to the flatfishes’ natural history, physiology and changes in their environment.
Flounder thrive best in cooler waters. Texas is the extreme southern edge of their range, something readily apparent in the fishes’ distribution along the Texas coast; flounder abundance is highest on the upper coast and declines down the coast. And that’s because of the fishes’ life history.
All about reproduction
The autumn migration of adult flounder from Texas bays to the Gulf of Mexico — the migration that triggers the flurry of fall flounder fishing — is tied to reproduction.
As autumn arrives, adult flounder in the bay systems begin heading toward bay/Gulf passes, moving in fits and starts along shorelines and channels. As they approach the passes, they invariably funnel into relatively small areas where they can congregate in large numbers and are extremely vulnerable to rod-and-reel anglers and, especially, to giggers who haunt shallow flats at night, spearing the fish as they rest on bottom.
Anglers can hammer these concentrated flounder. TPWD data from the 1980s through the mid2000s showed as much as 50 percent of Texas anglers’ annual flounder landings occurred during just three months — October through December. And as much as 25 percent of the annual flounder catch was taken during November alone.
The flounder that survive this gantlet move into the Gulf, often traveling dozens of miles offshore where they spend the winter, waiting for water to cool. Cold water with high salinity is crucial to flounder reproduction. The fish “free spawn,” with a female releasing eggs and males circling her, fertilizing the eggs. Those eggs and the larvae that hatch from them require high salinity (at least 30-35 parts per thousand) and cool temperatures (60 degrees or cooler) to survive.
Currents, wind and tide carry the larval flounder toward shore, where they are swept into the bays in late winter and early spring as they make their way to estuaries and, if they are very lucky, grow to adulthood in about two years and join the rest of the adults that trickle back into the bays during spring.
Water temperature key
Fisheries managers have identified poor recruitment — lack of young flounder entering the bays — as one of the factors behind the population decline. And a reason for that poor recruitment is tied to changes in water temperature in the Gulf. Over the last three decades or so, the temperature of the Gulf off Texas hasn’t gotten as low or stayed there as long as in past winters. Blame global warming or just a decades-long stretch of mild winters.
The most recent spring to see a true boom in flounder recruitment came in 1990, in the wake of the frigid winter of 1989. Since then, flounder recruitment has been on a slow, steady decline interspersed with occasional upticks, invariably following a relatively cold winter.
Faced with the declining flounder population and without the power to change the weather and order up cold winters, Texas fisheries managers addressed the issue with the only tool they had — regulations that reduce flounder harvest to increase the chances adult flounder could migrate to the Gulf and have a shot at reproducing.
Until 1988, Texas imposed no statewide bag limit on flounder. That year, it set a 20-flounder bag limit with a 12-inch minimum length for recreational anglers.
In 1996, that 20-flounder limit was halved, and two inches added to the minimum length.
In 2009, with flounder numbers still dropping and the number of coastal anglers more than doubling from the 1980s, the agency made radical changes to the flounder regulations, dropping the daily recreational bag limit to five flounder and commercial limit to 30 for 11 months of the year, but imposing a two-flounder bag limit for recreational and commercial fishers during November and banning all gigging during that month.
In 2014, the twoflounder daily limit was extended through Dec. 14, but the gigging ban was left in place only for November.
The regulations appear to have had a positive effect. At least things haven’t gotten worse.
Prospects looking up
Texas’ flounder population has stabilized over the last few years, albeit at a much lower level than in the 1980s, Tiffany Hopper, natural resources specialist with TPWD’s coastal fisheries division, told the Texas Parks and Wildlife Commission during a briefing last week.
Also, relative abundance of flounder, as gauged by gill-net surveys, has been on a slight increase since 2009, Hopper said. And catch rates for anglers have improved since bottoming out in 2010. A couple of decent years of flounder recruitment, including a good year in 2015, almost certainly played a role.
Anecdotally, Texas anglers reported a good summer of flounder fishing, and giggers in some bays had one of their best summers in recent years.
But flounder are far from being out of the woods. This spring, after the mild winter of 2015-16, saw the lowest flounder recruitment numbers from bag seine surveys since the surveys began 34 years ago.
The best thing that could happen for Texas’ flounder and flounder anglers would be for this winter to be a cold one, Hopper said.
The colder the better. shannon.tompkins@chron.com twitter.com/chronoutdoors