We’ll admit that some crawfish fans initially were excited about news that a few examples of an Australian redclaw species had been found in the Rio GrandeValley. Some people love the little mudbugs; Rotarians in McAllen and elsewhere hold annual crawfish boils and H-E-B holds special sales every spring, and the Australian critters can reach two pounds in size.
However, researchers at the University of Texas Rio Grande Valley, which found the crawfish in a pond at a Brownsville apartment complex, have expressed concerns about the find.
Environmental experts, and many government officials, worry when they learn about non-native, also called invasive, species. Because they are foreign, many don’t have native predators or environmental controls, and can overtake an area, to the expense of native species that lose food and habitat to the invaders. Some of those native species die out if they have limited diets and can’t compete with the competition.
To be sure, non-native plants and animals have benefited us greatly. Horses, pigs and other animals were brought here from other countries; about one-fourth of all plant species in North America, including many popular food crops, originated elsewhere.
Many transplants, however, have brought trouble, and even death. Yellow fever, which reportedly killed about 9% of the new American nation in 1793 and much of the Rio GrandeValley’s population a century later, is believed to have been brought here by mosquitoes that came here aboard freight ships from the Caribbean.
Former U.S. Forest Service director Dale Bosworth once estimated that invasive species cost this country more than $138 billion every year in total economic damages, control and eradication costs. Foreign insects and mites area said to cost farmers more than $15 billion a year in lost crops and pest control efforts. The U.S. National invasive Species Council — yes, there’s an entire government agency dedicated to it — holds invasive species responsible for significant levels of unemployment, damaged items, power outages, environmental degradation, increased rates and intensity of natural disasters, disease epidemics and lost lives.
We’ve seen the effects of natural invaders in the Valley. A big part of Gov. Greg Abbott’s illegal immigration control program is the control of carrizo cane, a reed that has overtaken the banks of the Rio Grande. It can grow 4 inches a day and impedes border officials’ enforcement efforts, and costs state government about $4 million per year. Within the river hydrilla proliferates, choking off other plants; it has been blamed for several deaths of people who have become entangled in the creeping plant when they’ve entered the river.
Like hydrilla, the Australian crawfish is thought to have dumped into our waters by a resident cleaning out an aquarium. Most popular tropical fish are native to Asia and South America, and releasing them into the wild might seem benign but can wreak havoc on local ecosystems.
Could there be a market for 2-pound crawfish? Who knows? But if there is, it’s best to address such a market through importation or farming, and not risk hurting local species in our open waters.
