Image credit: Wikimedia Commons
Tilapia—a fast-growing, highly palatable, fish native to Africa—has become a favorite among sustainability-minded diners. Indeed, when sourced from U.S. fish farms, the Monterey Bay Aquarium gives it a "best choice" rating.
But tilapia's hardiness, its versatility, its ability to grow quickly with little protein—the very things that make it so successful in aquaculture—mean that it is a dangerous invasive species when allowed to escape into new ecosystems.The newest region to struggle with invasive tilapia's insidious durability is the Fijian Islands. There, researchers have found a marked decline in the presence of native fish species. Particularly effected are various species of goby—a fish that matures in freshwater streams before moving into a saltwater habitat.
Researchers believe that the tilapia, now thriving in the rivers of some islands, eat the larvae and juvenile fish of the gobies before they have a chance to migrate from the streams. A survey found that streams with tilapia contained 11 fewer native species on average than those without.
Dr. Caleb McClennen, director of the Wildlife Conservation Society's Marine Program which led the study, explained that:
Protecting marine and aquatic biodiversity takes more than managing isolated rivers or coral reefs...a holistic conservation approach is needed, one that incorporates freshwater systems, the surrounding forest cover, coastal estuaries and seaward coral reefs. As aquaculture continues to develop worldwide, best practices must include precautionary measures to keep farmed species out of the surrounding natural environment.
This is certainly one issue in which consumers can help make a difference. By making ocean-friendly seafood choices at the market and demanding sustainable options at restaurants, you can help support responsible aquaculture.
Read more about invasive species:
The Iron Curtain Stopped Invasive Species
The World's Most Lovable Invasive Species
Eating Aliens: Are Invasive Species Ethical Food?
Read more about sustainable seafood:
8 Sustainable Sources of Farmed Fish & Seafood
Snowcamp Aquaponics: DIY Fish Farming with Zero Experience
How to: Choose your Fish Wisely