The mouth of the net is designed to stay open while it is being towed. This is achieved by attaching floats to the top of the net and weights to the bottom. These components create a vertical opening, ensuring the net remains open as it moves through the water. Horizontally, the net is kept open by “doors,” which are large rectangular wooden frames attached to the towing lines on either side of the net’s mouth. These doors spread the net wide, increasing the area it can cover and allowing for a more effective capture of fish.
The far end of the otter trawl, known as the "cod end," is constructed with a mesh size that is small enough to retain fish of edible size while allowing smaller, juvenile fish to escape. This design is critical for promoting sustainable fishing practices, as it helps prevent overfishing of young fish that have not yet reached maturity.
After a period of towing, the net is hauled back to the boat. The cod end is then secured with a strap and lifted out of the water. A specialized mechanism allows the bottom end of the net to open, releasing the fish onto the deck. This efficient process minimizes handling time, reducing stress on the catch and ensuring the freshness of the fish for market.
Recent advances in trawl design and technology have focused on improving selectivity and reducing bycatch, further supporting sustainable fishing efforts. Additionally, ongoing research aims to minimize the environmental impact of trawling on seafloor habitats, balancing the demands of commercial fishing with the need for conservation.
Understanding Otter Trawls: Design, Function, and Sustainable Fishing Practices
