Marine life, temperatures warm back up
Friday afternoon, as the water temperature in Texas’ bays rebounded from the dramatic plunge it took over a four-day stretch of freezing weather arriving with the new year, a boat piloted by Texas game wardens hauled a load of fin-flapping green sea turtles into the open Gulf near Port O’Connor and released them into the warming waters.
At the same time, Texas coastal fisheries crews were surveying the waters of the San Antonio Bay system where, the day before, state fisheries staffers had documented a scattering of dead fish — a couple of hundred or so speckled trout, redfish and sheepshead — along the Matagorda Island shoreline between Pass Cavallo and Pringle Lake.
Up and down the Texas coast, from Sabine Pass to Port Isabel, state and federal fisheries staff, game wardens and volunteers were busy dealing with and assessing the effects on marine life from the unusual, days-long bout of freezing and near-freezing temperatures that gripped the state.
Some of those effects were fairly easily seen and quantifiable, as with the green sea turtles.
Some, such as just how many coastal finfish the freezing temperatures claimed, remain to surface — literally. Green sea turtles stunned
The load of live green sea turtles Texas Parks and Wildlife Department game wardens released back into the Gulf just ahead of the weekend were among the more than 1,000 of the reptiles collected from frigid bay waters earlier in the week. The turtles, almost all of them juvenile green sea turtles, had been found floating or washed ashore, victims of the wintery weather.
The cold-blooded reptiles, evolved to live in tropical or semi-tropical water, suffer hypothermic distress when the water temperature drops below 50 degrees. The turtles’ bodies begin shutting down, their heart rate and circulation slows and they become lethargic and unable to swim. If exposed long enough to such cold water, the turtles go into shock and respiratory distress that can prove fatal.
On New Year’s Day, a cooperative effort was launched to collect as many cold-stunned sea turtles from Texas bays as possible, transport them to rehabilitation centers along the coast and keep the reptiles warm and fed until they recover their strength and the water temperature warms enough that they can be released.
That cooperative partnership, which included law enforcement and coastal fisheries divisions of Texas Parks and Wildlife Department, U.S. Fish and Wildlife Service, National Parks Service, NOAA, the Texas Sea Turtle Stranding and Salvage Network and citizen volunteers, retrieved an estimated 1,500 cold-stunned sea turtles from Texas bays.
Those turtles were transported to rehabilitation centers set up at a variety of state, federal and private sites that included the Texas State Aquarium in Corpus Christi, TPWD’s Sea Center Texas in Lake Jackson, the CCA/CCL Marine Development Center in Flour Bluff and NOAA/NMFS’s Sea Turtle Facility in Galveston.
Most of the cold-stunned turtles were found in the shallow waters of the Upper and Lower Laguna Madre, from Corpus Christi to Port Isabel.
Texas game wardens collected and transported to rehab centers approximately 500 turtles, with about 270 picked up by wardens working in the lower Laguna Madre, Col. Grahame Jones, director of TPWD’s law enforcement division, said Friday. But cold-stunned sea turtles were reported in every bay system except Sabine Lake. Wardens working in East Matagorda Bay picked up 151 cold-stunned sea turtles, with one boat rescuing 84 of the reptiles, Jones said.
TPWD coastal fishers crews rescued and transported more than 250 cold-stunned turtles, including about two-dozen found in the Galveston Bay system.
Rough estimates are that 70 to 80 percent of the turtles encountered by rescue crews were alive when found, with almost all of those expected to survive. But scores of sea turtles perished.
While the loss of turtles and the scale of the cold-stunning event is unsettling, the occurrence offers a measure of positive news for Texas’ coastal marine systems: It illustrates how the state’s green sea turtle population is increasing and extending its range.
Green sea turtles are native to Texas coastal waters, and once were abundant in the state. But unregulated, wholesale commercial harvest of sea turtles — a cannery was located in Rockport — during the late 1800s and early 1900s devastated the state’s green turtle population. By the 1920s, only remnant numbers survived, almost exclusively in the Lower Laguna Madre. Species shows resiliency
The turtles have made a dramatic comeback in Texas waters over the last three decades or so — the result of increased protections that include a total ban on harvest, mandatory use of turtle-excluder devices on shrimp trawls and a statewide ban on use of gill nets in coastal waters. While green sea turtles remain classified as a threatened species under federal and Texas law, their population and range significantly have increased under those protections — a point evidenced by the number of cold-stunned turtles seen along the length of Texas’ coast during last week’s siege of wintry weather.
Over coming days, as Texas bay waters temperatures rise to near seasonal averages, those hundreds of rescued turtles will be repatriated to the bays.
While the cold’s effects on sea turtles has been evident, that is not yet the case with the state’s inshore fisheries. But it should be in coming days.
The multiday cold-weather event dropped surface water temperatures in Texas bays into the low 40s and even pushed it into the high 30s in some shallow areas. Some of the fish found in Texas inshore waters — snook and gray/mangrove snapper — are extremely coldsensitive, facing fatal physiological consequences when water temperature drops below 50 degrees. Most inshore marine finfish such as speckled trout, redfish, sheepshead, black drum can’t survive extended periods in water temperatures below about 45 degrees and face almost certain fatal consequences if water temperature drops below about 40 degrees for more than a few hours.
In such cases, massive fish kills can result. Such freezetriggered mass mortality events killed tens of millions of inshore finfish during three events in the 1980s, devastating Texas’ inshore fishery and fishing for years.
Concern over the potential for a fish die-off from the extended cold weather caused TPWD fisheries officials to issue a two-day ( Jan. 2-3) prohibition on all fishing in 21 locations — channels, canals, harbors, warm-water discharges — that offered deep-water, insulated refuges to fish seeking to escape cold shallows. The move was designed to prevent plundering of the massive concentrations of vulnerable fish that could serve as seed stock to help rebuild populations should a major fish kill occur.
Coastal fisheries crews hit the water late last week to begin surveying Texas bays to gauge the cold snap’s impacts on finfish. So far, they haven’t seen a lot of dead fish.
That is what coastal fisheries officials expected. They hoped cold weather in December had given inshore fish time to acclimate and relocate to deeper water before the New Year’s blast. Plus, the frigid temperatures that hit the coast were not as severe or as long-lasting as the apocalyptic freeze events in the 1980s.
Too, any signs of a major fish kill can take days to manifest as most of the dead fish will sink to the bottom and become visible only days later when gasses created by decomposition cause the carcasses to float.
“It’s still a little early to know the magnitude of fish kills that may have occurred as a result of this freeze event,” Lance Robinson, deputy director of TPWD’s coastal fisheries division, said Friday. “We’re just beginning to see dead fish, but the numbers observed in the various kill locations number in the hundreds or less, not the thousands or tens of thousands that we’ve seen in past freeze kills.” Fish kills appear limited
Only a handful of reports of fish kills trickled in ahead of the weekend, with most of the reports indicating just a few dozen fish in isolated areas. The only reports of any consequence were of perhaps a couple of hundred trout, reds and sheepshead in Pass Cavallo/Pringle Lake area near Port O’Connor, and scattered dead gray snapper, small tarpon, mullet and other forage species in the Rockport and Port Aransas area, and a smattering of dead fish, most of them pinfish, pigfish, croaker and a few speckled trout in the Upper Laguna Madre.
In Galveston Bay, only a few scattered of handfuls of dead fish, almost all of them mullet, spadefish or other small forage species have been reported.
TPWD coastal fisheries crews will be on Texas bays daily through coming days and should have a more in-depth assessment of the cold snap’s effects by the end of the week, TPWD official’s said.
But early indications are that the state’s inshore fishery suffered only a glancing blow from what fisheries managers and Texas anglers hope was this winter’s worst stretch of cold weather.