Another common method employed by commercial fishermen in the northeastern United States is called “gillnetting,” where a net is spread out over a certain portion of the seafloor to target particular types of groundfish. Gillnets are made of vertical panels of netting and use strategically placed weights to make the structure suspend and hold open while in the water. Often, bait is used to draw fish to these nets or they are placed in areas where schools of fish will attempt to pass through the net. As fish swim into these nets, they become stuck partway through the mesh around their gills and cannot back out — hence the name “gillnet.” The mesh size, twine length, and overall net length and depth of gillnets are closely regulated to limit by-catch of unintended species when fishing.

Gillnets are commonly used by commercial fishermen in oceans and lakes throughout the world. Many salmon fisheries employ this method and have become successful in their low instances of catching non-target species. Here off the coast of New England, gillnets are used to target round fish such as cod, haddock, and pollock, as well as some pelagic species. To target these and other related species, many local fishermen use set gillnets, where the gear is set out in open water and anchored, using floats and weights to suspend the net vertically in the water. The net is then marked with buoys and left for a short, set period of time before it is hauled back to collect the catch. The vessels used to set these nets are specially equipped to set out the nets in a precise and accurate manner.

From a quality standpoint, gillnets must be hauled on a regular schedule to ensure that the catch is not left too long in the water where it can quickly deteriorate. Many of the independent fishing operations that use gillnets in New England are small-scale, and therefore haul their nets in short intervals, ensuring that the quality of the fish is maintained and that they are landed as close to being caught as possible.

Although gillnets have grown increasingly selective with advancements in technology and strict regulations, by-catch of unintended species remains an issue. Marine mammals and turtles can become easily ensnared in gillnets, and as a result, our local fishermen are working closely with regulators to ensure that as few unintended catches occur as possible. Regulations governing the placement, mesh size, and overall size of these nets helps to keep by-catch numbers down. Also, local fishermen have undertaken additional measures, such as purchasing and installing special “pingers” on their nets that make a noise designed to keep certain species of dolphins and whales from coming too close to gillnets.

For more information on gillnets and their use in Northeast Fisheries, please visit the following link:
http://www.fao.org/fishery/geartype/219/en