Prevent farmed fish escapes

What’s the issue? When aquaculture farms are connected to natural water bodies, some of the stock can escape. In some cases, escapees impact wild populations by competing with them for food, habitat and spawning partners.

Understanding the issue

Farmed fish differ from their wild cousins

Sometimes fish or shrimp on aquaculture farms manage to escape from the nets or pens and make their way into local waterways.  Occasionally, large-scale escapes—thousands of fish at a time—occur following storms or predator attacks on net pens. When this many fish escape at once, or some escape consistently, they can have a significant impact on the local ecosystem.

Sometimes, fish are farmed in areas they are not native to. If they can escape and establish themselves, they may compete with native species for resources like food and habitat. Where fish are farmed in their native waters, the concern is often genetic—if escapees breed with their wild counterparts, the genetic makeup of their offspring may be less suited to surviving and thriving in the wild.

Sustainable solution

Preventing escapes

To prevent escapes, farms should be constructed to withstand the local weather and climate conditions, as well as risks like predator attacks. Farmers should also have established procedures to monitor and maintain their facilities, and in the event of an escape, response plans.

Technological advances have made it possible to raise fish—even large finfish like salmon and striped bass—on land. Large tanks provide fish with continuous water flow and some pump wastewater through treatment systems before returning it to the tank. These recirculating tanks prevent escapes of farmed species.