By Melissa Gaskill
Texas Climate News
Hurricane Harvey made landfall at Rockport, Texas, on August 25 as a Category 4 storm, bringing with it 130-mile-per-hour winds that caused massive destruction from Port Aransas to Port Lavaca. The storm then dumped 52 inches of rain on parts of Houston on August 26. After a brief refueling over the Gulf of Mexico, it inundated the Port Arthur/Beaumont area with up to 60 inches on August 30. Harvey set new records for the largest five-day rainfall over an area of 10,000 square miles and for the longest time a hurricane hitting Texas has remained a named storm after landfall.
More than 80 people died, and thousands of homes, businesses and farms were damaged or destroyed. According to the National Oceanic and Atmospheric Administration, the total cost of damage could be as high as $190 billion.
The natural world suffered as well. Some animals had no way to escape the storm or sought shelter in areas that flooded in the torrential rains. Those able to flee lost valuable habitat to Harvey’s high winds and rain. The area affected by Harvey contains multiple national wildlife refuges, state parks and Wildlife Management Areas and a number of protected areas, including Audubon Society and Nature Conservancy preserves. All experienced high winds, flooding and storm surge.
Coastal ecosystems evolved along with hurricanes but may take longer than usual to recover from a storm of Harvey’s magnitude. The limited amount of natural area affects whether and how well wildlife recovers; most animals cannot simply move to undamaged habitat because none exists.
Rich Kostecke, associate director of research and planning for The Nature Conservancy in Texas, says long-term impacts to wildlife remain mostly speculative until scientists have more time and data. Harvey affected a lot of stopover habitat for migratory birds, he points out, and distribution of species may change in response. Going forward, invasive plant species represent a potential wildlife-related concern, as invasives tend to take advantage of major disturbances.
TCN takes a look at how Harvey affected three endangered species:
Attwater’s Prairie Chicken
At least a million Attwater’s prairie chickens once lived on the coastal prairies of Texas and Louisiana. The birds disappeared from Louisiana by 1919, and in 1937 only about 8,700 remained in Texas. The species received protection under the Endangered Species Act in 1973, but with less than one percent of coastal prairies remaining, the Attwater’s prairie chicken remains one of North America’s most endangered birds.
Before the storm, the Attwater Prairie Chicken National Wildlife Refuge tracked 29 individual birds, mostly hens. Post-hurricane, staff confirmed only five of them still alive.
High winds and torrential downpours killed many of the birds, says refuge manager Terry Rossignol. In addition, prairie chickens seeking dry land in the midst of flooding likely ran into predators with the same idea, causing an indirect effect of higher-than-usual predation. The small size of the population — fewer than 100 birds left in the wild — magnifies such an effect.
Three facilities in Texas breed these birds for release at the refuge. Before the storm, a group of 20 birds had been in acclimation pens for a week in preparation for release. Staff returned those birds to the Houston zoo and released them post-Harvey, along with five others from the Caldwell Zoo in Tyler and another group from Fossil Rim Wildlife Refuge.
The hurricane also killed roughly 80 percent of a prairie chicken population on private property in Goliad County.
Every whooping crane alive today descended from 15 cranes wintering at the Aransas National Wildlife Refuge in 1941. Today, the only natural wild flock of whooping cranes migrates 2,500 miles twice a year, nesting in Wood Buffalo National Park in Canada’s Northwest Territories and wintering at Aransas NWR. The nearly-five-foot birds, tallest in North America, take their name from loud vocalizations during their elaborate courtship ritual. Pairs mate for life.
Fortunately, Harvey hit before the flock departed Canada. The birds start their fall migration in late September, arriving in Texas between the middle of October and the middle of December.
Wade Harrell, Whooping Crane recovery coordinator for the U.S. Fish and Wildlife Service at Aransas NWR, says Harvey’s storm surge peaked at 9 to 11 feet and reached a mile and a half inland. This saltwater inundated many of the refuge’s freshwater wetlands and ponds that cranes rely on for drinking water. Some ponds increased from normal levels of 0 to 2 practical salinity units to as high as 16 to 18 psu.
Rain will gradually restore normal salinity levels, but in the meantime, the birds may need alternative sources of freshwater. Cranes prefer open, prairie habitat because they can see predators coming. The refuge becomes more wooded farther inland, and using ponds in these environments puts the birds at higher risk of predation.
So far, refuge staff have not seen any effect on the cranes’ food supply. But Harvey did leave significant amounts of human debris on the refuge, including refrigerators, propane tanks, and barrels, which could pose a risk of contamination. “We don’t want to bring in heavy equipment to clean up the debris in the winter when the cranes are there,” Harrell says.
Five species of sea turtles, all threatened or endangered, occur in the Gulf of Mexico: Kemp’s ridley, green, hawksbill, loggerhead and leatherback.
Kemp’s ridleys spend most of their lives in the Gulf and nest on its beaches, mostly in Mexico. In the US, most nesting occurs in Padre Island National Seashore. Some green and loggerhead sea turtles also nest on the Texas coast, mainly at the Seashore. Juvenile greens frequent Texas waters.
Sea turtles fared pretty well in the storm, considering, says Donna Shaver, director of the Division of Sea Turtle Science and Recovery at Padre Island National Seashore.
Shaver did not document any nests lost to the hurricane, because eggs are brought into an incubation facility. When Harvey hit, nesting Kemp’s ridley females had all left the area, and all Kemp’s clutches had hatched and been released. Four clutches — three green and one loggerhead — were released just before the storm, and another clutch rode out the storm in the facility, with hatchlings released between September 28 and 30. Shaver notes that beach erosion caused by Harvey will likely heal and not affect the 2018 nesting season.
Texas saw only four “wash backs” — post-hatchlings washed back onto the beach — the week after the storm, according to Shaver. How hatchlings, juveniles, and adult sea turtles farther out in the Gulf fared is hard to say, she adds. However, Shaver has tracked adult female sea turtles since 1997 and observed some individuals riding out hurricanes. One tagged sea turtle, Kimberly, remained on the west coast of Florida during Irma apparently with no ill effect; she last checked in on Halloween.
News from Florida was not all so good: Irma destroyed more than 3,000 loggerhead nests and nearly 9,500 green nests.
Several species of sea turtle depend on coral reefs for food and shelter. Harvey washed more than 13 trillion gallons of floodwater into the Gulf of Mexico, which threatens coral reefs in the Flower Garden Banks National Marine Sanctuary, 100 miles from shore. Most coral species prefer salinity levels between 32 and 42 parts per thousand. A monitoring buoy near the Sanctuary measured a 10 percent drop in salinity, from 36 to 32 ppt, on September 28. Hurricanes also can cause physical damage to coral reefs, although the depth at the Flower Gardens provides some protection. Scientists continue to monitor the health of these reefs.
Melissa Gaskill is a Texas Climate News contributing editor. An Austin-based writer, Gaskill’s work has been published by Nature News, Scientific American, Wildflower, Texas Parks & Wildlife Magazine, Smithsonian, Men’s Journal and others. She received a bachelor’s degree in zoology from Texas A&M University and a master’s degree in journalism from the University of Texas at Austin.