Diamondback Terrapin in marsh habitat
Texans love turtles. It’s hard to drive by a pond in summer and ignore the basking sliders with their back legs stuck out straight like they’re impersonating Superman. It’s even harder to take a hike out west and not become enamored by the slow plod of an ornate box tutle sharing the trail with you. Texas has about 30 species of shelled reptiles. Most of them occur in freshwater habitats, a few occur in the marine environment, but just one species can only be found in the brackish waters that exist where our rivers meet the sea -- our diamond in the marsh, the diamondback terrapin.
Diamondback terrapins are unique in many ways and most of these come from their adaptation to life in estuaries, salt marshes, and bays along the coast. Obtaining freshwater to drink is always a challenge in a salty environment but terrapins are known to skim it off the surface of the water just after it rains before it mixes or to binge drink after from pools that form in the muddy marsh. Finding safe and dry nest sites can also be a challenge in a landscape where the water level fluctuates due to tides, river flows, and storms. Females are much larger than males and this is thought to be because females and males prefer different foods, in addition to the traditional body size differences between sexes because females produce the eggs.
Male Diamondback terrapin
Female Diamondback terrapin
Diamondback terrapins are among more than 1,300 Species of Greatest Conservation Need (SGCN) in Texas. The principle reasons for concern about this species are loss of estuarine habitats due to development along the coastline and by-catch mortality from active and lost blue crab traps. Fortunately, research performed over the last decade from biologists at the Texas Parks and Wildlife Department, University of Houston-Clear Lake, and Texas A&M University-Corpus Christi provide information and conservation solutions to these problems.
First, TPWD’s annual crab trap cleanup program removes thousands of derelict “ghost” crab traps from Texas estuaries each year. These abandoned traps are often lost by fishermen during storms and volunteers are encouraged to patrol the coast to remove them.
Derelict crab trap -- Rachel Rommel
Volunteers cleaning abandoned crab traps during annual clean up -- Rachel Rommel
Additionally, we are fortunate that the Texas coastline has numerous protected areas, such as National Wildlife Refuges, Wildlife Management Areas, and State Parks. These areas provide important nursery habitat for economically important fish species, help filter and clean water as it makes it way to the coast and provide buffering for coastal communities against increasingly intense storms. With additional research and an understanding of where terrapin populations are and what key habitat feature’s they are using, we can help manage this species in these protected areas.
Finally, research has shown that voluntary participation from blue crab fisherman along the coast in a by-catch reduction device program can help reduce accidental mortality of terrapins in crab traps in high density terrapin areas. Additional resources for the production of devices and investment in awareness campaigns can help increase the scope and impact of the adoption of this conservation program.
The Recovering America's Wildlife Act would provide essential funding to help the diamondback terrapin conservation and hundreds of other fish and wildlife species in Texas. You can help #RecoverWildlife by taking action using the online toolkit.