Freeze hurts, but not to dire degree
The winter storm that swept across Texas and took power, water and lives last month also hit the state's coastal fisheries.
Fish kills due to the freeze were reported along the entire Texas coast. Mark Fisher, the Texas Parks and Wildlife Department's coastal fisheries science director, said it was the most severe fish-killing event since 1989.
The freeze of 1983 and the twin freezes of February and December 1989 marred coastal fisheries and changed the way they were managed for years to come. The early assessment indicates this recent Arctic blast was not as destructive to fish populations as the 1980s freezes.
“Those three events in the '80s, those were the benchmarks and they were devastating. They were a lot worse,” said Fisher.
“The one thing we had going for us in this event was that we went into it with relatively warm water temperature. It was upper 60s to 70s in most areas, so we had a nice little buffer. Plus, we didn't get to the really cold air until several days later. So, we had a relatively gradual cooldown.”
Fish kills were widespread, but the Upper Coast appears to have fared far better than areas farther south. The kills at Galveston and Sabine Lake appear to be minor and limited to isolated incidents, such as on Keith Lake and neighborhood canals on Tiki Island and Jamaica Beach.
The major impacts have been observed from Matagorda southward.
Among the hardest hit “hotspots” is Pringle Lake, which lies between Matagorda Bay and San Antonio Bay and consistently has fish kills during freezes due to its shallow water. The Land Cut on the Laguna Madre also was afflicted. Matagorda Bay, San Antonio Bay, Aransas Bay, Corpus Christi Bay and the Upper and Lower Laguna Madre all had areas that sustained significant mortalities of multiple species.
Coastwide, most of the deaths consisted of baitfish, including mullet, menhaden, spot, silver perch (yellowtail) and other forage species. Subtropical fish like snook and gray snapper, species that are less tolerant to cold water temperatures, suffered heavy casualties. Fisher was surprised by some loss of tarpon, a migratory species, that were reported. Apparently, a few stragglers did not make it out in time.
Flounder, a cold-hardy fish, were largely unaffected. The freeze hit speckled trout harder than redfish, which are more resistant to the cold.
“We're seeing more trout than reds,” Fisher said.
Fisher said that speckled trout have a few biological advantages that can help with recovery. Speckled trout are incredibly resilient and can spawn millions of eggs over an elongated timeframe. The species spawn from April through October. Hatcheries, too, like Sea Center Texas in Lake Jackson and the CCA Marine Development Center in Corpus Christi, are set to ramp up speckled trout production to assist with the rebound of one of Texas anglers' most beloved fish.
The actual dead fish, too, as smelly and unsightly as they may be, will play a role in restoring Texas' bays.
“What we have is all of these decaying fish releasing nutrients into the water and that's going to fuel an amazing regrowth in the spring. I like to say it's akin to a forest fire effect,” Fisher said.
The full extent of the freeze's impacts on finfish populations and the effect of the baitfish kills on the ecosystem will be ascertained through an ongoing process. TPWD will gather information from anglers at boat ramps with creel surveys. Gill net surveys will help tell the tale of how adult redfish and speckled trout survived the storm. Bag seine and trawl net surveys will give a representation of reproduction efforts. All of this data collection will help clarify the picture through the spring and into the summer and will determine if regulatory changes are needed to restore the fishery.
Fisher said that most fish populations were at a level of abundance that could sustain this sort of event.
No species epitomizes that notion more than the green sea turtle.
There were 11,591 coldstunned sea turtles reported along the Texas coast due to the recent freeze, according to the Sea Turtle Stranding and Salvage Network. And that count is still ongoing. That number more than triples Texas' total from the winter of 2017-18 and is more than double the previous record of 4,613 turtles in Florida in 2010.
Green sea turtle populations have been growing and expanding their range with the help of conservation efforts, milder winters and mandated turtleexcluder devices in shrimp trawlers.
Turtles were in need of rescue during the freeze because they become lethargic and are unable to swim when water temperatures drop below 50 degrees.
Inland fisheries also were affected by the freeze, but not as severely and not to the detriment of freshwater sport fish.
“Fortunately, impacts to inland, freshwater fisheries have likely been minimal, especially when compared to impacts observed along the coast,” said Craig Bonds, TPWD'S inland fisheries division director.
Most freshwater species can survive cold weather events, but lakes in the northern portion of the state were more susceptible to threadfin shad die-offs, including Lake Texoma, Lavon Lake and Lake Graham. Those shad populations should recover quickly during the spring spawn.
Non-native tilapia die-offs have also been reported in South Texas.
Inland waterbodies also benefited, with the freeze purging invasive aquatic species such as giant salvinia and water hyacinth.
“In 2018, with a much shorter duration of extreme cold, we estimate that giant salvinia coverage was reduced by as much as 98 percent,” said Monica Mcgarrity, senior scientist for aquatic invasive species management in TPWD'S inland fisheries division.
Mcgarrity notes that the freeze cutting down these aquatic invasives is likely a temporary reprieve, and that the salvinia weevils used to help control the spread also were killed by the cold.
“While this may reduce the infestation levels for 2021, giant salvinia grows and expands rapidly, and since 2018, we've seen the giant salvinia regain a foothold and expand, even spreading to new lakes,” Mcgarrity said, adding that water hyacinth can overwinter seeds in lake sediment and sprout when spring comes.
Like the assessment of coastal fisheries, it will be the weeks and months ahead that determine the full extent of the freeze's impacts on the ecosystem.
Texas Outdoor Family: Hands-on basics of camping for those with little or no experience with tent, gear provided, Palmetto State Park. $75 for family of up to six. Call 512-3898903 or email tofsp@tpwd.texas.gov.
MARCH 24-25
Texas Parks & Wildlife Commission: Regular meeting, 9 a.m.-5 p.m., TPWD headquarters, 4200 Smith School Road, Austin. Click on tpwd.texas.gov.
MARCH 24
Texas Parks & Wildlife Department: Deadline for public comment on proposed changes to freshwater and saltwater fishing regulations including changes to length and bag limits for blue and channel catfish statewide and at specific locations and clarifying red snapper bag limits when fishing in Texas and federal waters. Click on tpwd.texas.gov/ business/feedback/public_comment.
MARCH 26-28
San Antonio Boat & Outdoor Expo: Latest models of RVS, bay and offshore boats, personal watercraft, kayak and wakesurfing; gear; seminars; fishing tank; Expo Hall, AT&T Center grounds. Call 512-481-1777 or click on sanantonioboatshow.com.
APRIL 1
Texas Parks & Wildlife Department: Deadline for registration for the Great Texas Birding Classic, which runs from April 15-May 15. Click on tpwd.texas.gov/events/great-texasbirding-classic.
APRIL 8
Cibolo Nature Center & Farm: Native Hill Country Plants for Birds, online workshop 6-7:30 p.m. $5. To register, click on cibolo.org/calendar.
APRIL 10-11
Texas Outdoor Family: Hands-on basics of camping for those with little or no experience with tent, gear provided, Pedernales Falls State Park. $75 for family of up to six. Call 512389-8903 or email tofsp@tpwd.texas.gov.
APRIL 15
Cibolo Nature Center & Farm: Virtual Birding by Ear Workshop, 6-8 p.m. $5. For more information, contact Laurie Brown, 830-388-7680 or laurie@cibolo.org. To register, click on cibolo.org/calendar.
Have an item for the calendar? Email John Goodspeed at john@johngoodspeed.com .