Untangling the Threads: A Deep Dive into Trawl Ropes and Nets

Trawl Ropes and Nets: Innovations in Optical Ropes and Nets for Fisheries

A Brief History of Bottom Trawling

Bottom trawling is a fishing method that involves dragging heavy nets along the seafloor behind boats. This practice has been used commercially since the late 19th century and involves deploying massive nets, sometimes over a mile wide, that are towed along the ocean bottom. Ropes connect the nets to heavy discs, or "tickler chains," that are dragged along the seafloor to stir up fish and crustaceans from their hiding places so they can be caught in the nets.

Unseen Damage to Seafloor Habitats

While trawling efficiently catches target species like cod and shrimp, the heavy gear also damages fragile seafloor ecosystems in the process. Coral reefs, sponges, and other structures that provide shelter and habitats for many ocean species are vulnerable to being crushed or uprooted by tickler chains and nets. Habitat destruction harms biodiversity by reducing suitable living spaces for plants and animals. Ghost fishing also occurs when trawl ropes and nets continue to ensnare creatures long after a trawl.

Bycatch and Discard Impacts on Wildlife

In addition to altering benthic habitats, trawl fishing has substantial bycatch where non-target species are also caught in nets. Dolphins, sea turtles, sharks, seabirds and other at-risk animals may drown or become injured after being hauled aboard trawlers. Regions with high ecosystem protection recognize the threats to endangered wildlife and have enacted regulations on net and rope materials, tow times, and exclusion devices to allow escapes of protected species. However, large quantities of bycatch are still discarded at sea, dead or dying, as a result of bottom trawling globally each year.

Gear Contamination of Seafloors

derelict fishing gear, which gets lost or intentionally discarded during fishing operations, can continue impacting ocean habitats. Ghost fishing refers to when trawl ropes or nets still line