A huge net, weighed down by heavy chains, swiftly sweeps across the ocean floor, scooping up everything in its path. 

This type of fishing, called bottom trawling, was illuminated in a new documentary, Ocean with David Attenborough. 

Bottom trawling is known for indiscriminately gathering all sorts of marine species, as well as damaging the sea floor. 

But with the practice producing around a quarter of the world’s wild-caught seafood, are there ways to make it more sustainable?