SAN ANTONIO — People who stroll the San Antonio River in the Pearl area can’t help but notice the eye-popping pink egg sacks that cling to the sides of the river channel.
Biologists say the brightly colored thumb-sized blobs are evidence that a South American stowaway is gaining a foothold in our river.
The egg sacks are the beginning stages of an invasion by apple snails.
State wildlife officials say they are Pomacea Maculata, an invasive species that has no known predators in the San Antonio River basin.
Because nothing eats them, biologists say they are free to reproduce at will, and take over territory and resources that rightfully belong to native species.
While the egg sacks begin their life journey above the water line, the mature animals live in the water and biologists say they can grow to be the size of an apple, eating their way through native vegetation and damaging the river bed and banks with burrowing behavior.
River Authority biologists have been fighting to remove the invasive spiral-shelled creatures for a couple of years, but they say the job is so big, they are now recruiting volunteers.
They want anglers and those who kayak to come to the river with eyes wide open.
They are offering training for volunteers to properly remove the pests from the river.
They call the volunteer effort the River Warrior program.
Shaun Donovan, with SARA, said “Their origins here in our basin are likely people’s aquariums and they drop them into the river and it’s a really bad idea to have any non-native in the system. At best, it’s a benign impact but at worst they can start out-competing or they can start taking resources from our native species.”
Donovan said anyone who likes to spend time on the river is welcome to help with the job of removing the snails, but training is essential.
“The best thing to do if you want to help us with the apple snails is to get in contact with our education group and sign up with the River Warriors,” Donovan said.
Donovan said while simply handling the creatures may not be dangerous, they can carry disease.
“Do not eat these apple snails at all. It’s not a good idea because they can potentially carry a parasite,” Donovan said.
Donovan said the rat lung worm parasite hasn’t been found in Texas yet, but it has been identified in snails as close as Louisiana.
Donovan said beyond safety concerns, it is a violation of state game laws to possess adult snails without a proper permit.
“We can handle them because we have a permit through the state to handle invasive and exotic species, but we encourage you, if you do see an apple snail report it to us. We’re happy to help out as much as we can but we encourage you, do not pick up the adults at all,” Donovan said.
While the adults are especially problematic, Donovan said disposing of the egg sacks found on river banks is much simpler.
Donovan said “You can dispose of the egg cases, without being part of the permit. Get that training and fully understand what the expectations are and the best way to mitigate the issue.”
Donovan said this river-wide problem will take a coordinated approach to solve.
“It’s definitely a problem it’s going to take a community to solve and it’s always great for people to come out and utilize the natural resources that we have and be responsible,” Donovan said.