Over the past weeks, as Texas rivers bloated to overflowing with churning runoff from May’s record-setting rains poured into the state’s reservoirs, swelling some lakes to more than twice the size they’d been just a month or so before, Todd Engeling has thought of a saying common among managers of freshwater fisheries.
“There an old adage that’s been around for a long time among fisheries biologists: ‘Stock on a rise, and advertise,’?” Engeling, fish hatchery program director for Texas Parks and Wildlife Department’s inland fisheries division, said. “When you have conditions like we’re seeing – lake levels rising and covering all that shoreline vegetation – that’s going to improve survival of fish you stock as well as survival of the natural spawn. It means fishing’s going to get good.”
If the adage proves prescient, a lot of Texas lakes are going to see a flush of improved fishing over coming years as freshwater fish hatched in 2015 become part of the fishery. And on some Texas waters, a good number of the fish anglers catch a year or two or five years or more down the road will have direct ties to work done this spring by Engeling and other staff in TPWD’s inland fisheries hatcheries branch.
Over the past weeks, inland fisheries crews have stocked more than 7.5 million fish – most of them fingerlings, all produced in the state’s four operating freshwater fish hatcheries – into dozens of waters across the state. Included in that number are 3.4 million Florida-strain largemouth bass, 2.2 million striped bass and 1.4 million striped/white bass hybrids as well as 40,000 bluegill and about 117,000 Guadalupe bass.
The agency plans to begin stocking millions of channel catfish into public waters during July, Engeling said.
Production and timing of the release of those hatchery-produced fish are coordinated to mimic the natural chronology of particular species – when released, hatchery-produced fingerlings of most species are about the same size as their reservoir-native relatives produced through natural spawns.
With striped bass and hybrid bass – fish not native to Texas and, in the case of all hybrid bass and most striped bass, incapable of natural reproduction in Texas water – the fishes’ release is timed to get the young fish in the water when forage, water temperature and other conditions are most conductive to their survival and growth. Hybrid bass fisheries and all but a couple of striped bass fisheries in Texas are put-and-take fisheries, wholly dependent on hatchery stockings to support the fishery.
Odds of those young hatchery-produced fish and the ones produced in natural spawns on Texas lakes surviving look much brighter today than they did before the rains fell.
In many reservoirs, particularly in the western half of the state, almost a decade of drought had shriveled the lakes. Those dropping water levels greatly reduced littoral habitat – shallow waters holding aquatic vegetation and other cover – crucial to survival and growth of many fish, including largemouth bass, crappie, sunfish and many of the forage species on which they feed.
Dropping water levels and reduced flow of nutrients into reservoirs as river flows dwindled also reduced the amount of open-water habitat used by hybrid bass, striped bass and threadfin shad, the main forage for hybrid and striped bass.
Under those poor habitat conditions, spawning success was poor and survival of those young fish low.
Also, in some reservoirs and rivers, particularly on the upper Brazos, Colorado, Red and Pecos rivers, drought caused waters to turn increasingly salty, triggering outbreaks of golden algae, a toxic-to-fish microorganism that thrives in saline waters.
Stocking hatchery-produced fish into deteriorating fisheries where survival of the fingerlings would have been low was suspended.
The drought also significantly affected TPWD’s hatchery operations. Because of the drought, the agency’s Dundee Fish Hatchery near Wichita Falls has been off-line for three years. Kemp Lake, the public reservoir providing the water used by the hatchery, shrank to a quarter of normal capacity. Concerns about water quality and the need to use Kemp’s limited resources to supply water to nearby residents forced TPWD to suspend operations at the Dundee hatchery.
“That really hurt our ability to produce fish,” Engeling said. “With Dundee closed, we lost about 30 percent of our production capacity.”
Engeling said he has hopes the Dundee Hatchery can be back into at least limited production perhaps as soon as later this year, thanks to the same May rains that left much of Texas awash in water. Lake Kemp’s water level jumped 11 feet over the past month, expanded in size from less than 5,000 acres three months ago to more than 8,400 acres this past week, and holds a little more than 60 percent of its capacity.
Like Lake Kemp, almost all of Texas’ 500-plus public reservoirs have seen their water levels significantly rise over the past month, with some lakes seeing spectacular expansions.
Lake Travis on the Colorado River upstream from Austin saw its water level jump more than 45 feet in the past month, with the lake’s surface growing from 9,200 acres to 16,300 acres.
A month ago, Lake Medina, on the Medina River south of San Antonio, was 85 feet low, held only 4.5 percent of its normal capacity and covered only 780 acres. The lake level rose 65 feet in the past month, increasing the lake’s surface acreage to more than 4,400 acres.
Dozens of reservoirs in the eastern half of the state are far over their normal levels. Lake Texoma on the Red River is 22 feet above it’s “full” mark. Most lakes in north-central Texas are at or far above full. Lake Somerville on the Brazos River drainage near Brenham is 18 foot above full. Sam Rayburn Reservoir is almost 10 feet above “full.”
“A number of lakes that really need it caught water,” Engeling said. “That’s going to really help.”
All that rising water has inundated grass, brush, trees and other vegetation, providing young fish with cover from predators. The influx of nutrients from the flooding river will boost phytoplankton and zooplankton production, fueling the base of the food chain. And as drowned terrestrial vegetation deteriorates, it will release more nutrients into the food web, sustaining increased productivity for months or even years. Spawning success, survival of young fish and growth rates significantly increase.
Fisheries biologists term this explosion of productivity, similar to what’s seen when a reservoir is originally filled, the “new lake effect.”
“You’re going to see this ‘new lake effect’ on a lot of reservoirs,” Engeling said.
And Engeling is going to get a lot more stocking requests from TPWD inland fisheries biologists for the relatively limited number of fish the state’s inland hatcheries produce.
“We’ve always had to prioritize our stockings. Over the past few years, with the drought, some lakes haven’t been on the stocking list because it didn’t make sense to stock fish when we knew survival would be very low,” he said. “But with this rain, I’ve already got people on lakes that were suffering and finally caught a lot of water – like Medina – calling and asking, ‘Can we get some fish?’
“I anticipate that next year some of those lakes will get a lot of attention,” he said.
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