February 21, 2020 — For fisheries managers around the world, trawl gear is an efficient way to sample species inhabiting the sea floor or the benthic column above. Depending on the size of the net, grid surveys will capture enough of the animals in the area at the time to compile data used in abundance models that go into stock assessments. Unless the fish swim out of the net before it is hauled. Or unless the sea bottom is rocky or pinnacled.
In those areas, longline gear can help fill in the blind spots for regional surveys. Longline gear can be lain across rock piles, and retrieved without destroying the gear itself. It differs from a trawl net in several ways: the longline has baited hooks distributed evenly across its length, it is stationary, anchored to the sea floor with location buoys at the sea surface at each end, and it can be deployed by smaller vessels.