River Threats - Apple Snails

The River Authority
Aug 14, 2020

An ecosystem is an interconnected community of living things, such as plants, animals, and microbes, and the nonliving environment such as air, climate, water, and minerals that surrounds it. The San Antonio River Authority (River Authority) is proactive when it comes to protecting our natural resources and staff has been hard at work to address invasive species as part of our commitment to safe, clean, and enjoyable creeks and rivers. 

Most recently, the San Antonio River has faced a new threat to its ecosystem. River Authority biologists first responded to the observation of apple snails along the Museum Reach section of the San Antonio River Walk in October 2019. Learn more about this non-native species and what the River Authority is doing to address its presence.  

What are Apple Snails?

Cluster of Apple Snail eggs found along the San Antonio River.

Giant Applesnails (Pomacea maculata) are native to South America and highly destructive invasive species throughout Texas. As such, they are on the Texas Parks and Wildlife (TPWD) Invasive, Prohibited, and Exotic Species list

The snails are voracious eaters of aquatic plants that take away foodstuff and habitat from the river's native species. Typically sold at pet shops, it is assumed the snails outgrew their aquariums and were released into the river.

How is the River Authority addressing this invasive species?

The scheduled river draining in January 2020 by the City of San Antonio provided River Authority crews an opportunity to remove many snails and egg cases. The bright pink egg cases hold thousands of eggs!

To date, River Authority staff have been out in kayaks and have removed nearly 100 adult apple snails and well over 1,000 egg cases. Staff routinely maintains the Museum Reach and the King William section of the San Antonio River Walk to continue to monitor new findings.

What can you do?

River Authority staff removes Apple Snail egg clusters along the San Antonio River

Please remember, never dump your aquarium into the river or any other freshwater or saltwater body. You can also report any sighting of egg cases or adult snails by calling toll free at (866) 345-7272 or contact us through our website. Your help with reporting this invasive species will assist our Environmental Sciences Team to further study and remove the presence of this non-native species along our creeks and rivers. Finally, we will soon be training volunteers to help us track and remove apple snail egg cases. If you're interested in helping us manage this invasive species or participating in any of our other volunteer service projects or educational trainings, please sign up and join the River Warriors.

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