Northern or cold-water shrimp is one of the most abundant shrimp species found in the North Atlantic and Pacific. They are live in soft, muddy substrate on the ocean floor. To grow, they must periodically shed their outer shells in a process known as molting whereby they crawl out of their old shells and their bodies absorb water to increase in size before the new soft shell begins to harden.
Northern shrimp have a hard outer shell and jointed legs, and can grow up to 16 cm long. They have large, bulbous eyes and breathe through their gills. The bright pink shell covering the head and body has a long, curved, sword-like structure called a rostrum that is covered in numerous spikes. Northern shrimp are sweet and delicate, and are often served in sushi restaurants as ebi.
In the northwest Atlantic, northern shrimp mate in late summer and fall. Once fertilized, the eggs remain attached to a female's abdomen until the following spring. A female usually carries around 1,700 eggs. After incubating for seven to eight months, the eggs hatch in April or May in the form of larvae. The larvae feed on plankton as they drift near the top of the water column. After a few months, they begin to spend more time near the bottom and start to look more like adults. Most shrimp reach male sexual maturity during the second or third year of life. In the winter of their fourth or fifth year, northern shrimp will transition from a male form to a female form. The ovaries will ripen the following summer and mating takes place in the fall. They can live up to eight years.
This fishery uses a large cone-shaped net that is dragged along the seafloor to catch fish. As the net is towed at low speed, hydrodynamic forces push two "otter boards" outwards opening the mouth of the net and capturing fish in its path.