New trap reduces bycatch in Africa
Scientists from the Wildlife Conservation Society and the Kenyan Marine and Fisheries Research Institute have helped build a fish trap that keeps valuable fish in while letting undersized juvenile fish and non-target species out.
By modifying conventional African basket traps with escape gaps, the marine researchers have proven that the new traps catch larger fish, allow more undersized and non-target fish to escape, increase profits, and minimise the impact of fishing on coastal reef systems. The findings, say researchers, will help fishing communities boost profits while protecting their vital marine resources.
The study was conducted in the fished reef systems near a marine park on the coast of Mombasa, Kenya. The researchers worked with an experienced trap fisher who built six basket traps - iron-framed structures with netting and a single, tube-shaped opening leading into the middle of the trap. Half of the traps were constructed with escape gaps measuring 12 inches by an inch and a half. The escape gaps were designed to allow undersized and non-target fish to exit while retaining commercially valuable adult fish.
The traps were monitored and the researchers found that the fish captured in the experimental traps were on average 31% longer and 55% heavier than fish in the regular traps without gaps.
The escape-gap traps also allowed smaller non-target fish to escape.
“These new escape gaps are a game changer for Kenya’s coastal fisheries,” said Dr. Caleb McClennen, Director for WCS’s Marine Programs. “By reducing bycatch, the new basket traps increase fish size, economic return, while limiting the bycatch that can harm entire reef systems. These innovations can also be exported to other coastal fisheries for the benefit of entire regions.”