Northern shrimp, Pandalus borealis, live in waters off the coast in both the North Atlantic, North Pacific, and Arctic Oceans. They live in soft muddy bottoms at depths of about 30 to 1,000-feet.
The northern shrimp has several feeding habits designed to make the most out of a variety of situations. It can feed on the ocean floor for random material as a scavenger, while it is also a predator on small invertebrates. It is also able to filter-feed during migrations to the water column in the night. Most shrimp do not live past the age of five.
Northern shrimp are hermaphroditic. When it matures sexually it first becomes a male but later changes its gender and turns female. This happens at different ages, due mostly due to sea temperature and other environmental conditions.
They are medium-sized shrimp with a thin body. They have a uniform pink color and no banding. Its third abdominal segment, at the bend in the abdomen, has a distinctive dorsal spine. There are also single spines on the rear margin of the third and fourth segments.
In the Pacific Ocean, northern shrimp are also called pink shrimp, northern pink shrimp, Alaska pink shrimp, or spiny shrimp. Until recently, they were considered the same species as the pink shrimp, Pandalus borealis, found in the north Atlantic. The Pacific population was reclassified as P. eous in 1992. However, some taxonomists consider the Pacific population to be a subspecies, P. borealis eous. For this reason, the scientific name P. eous has not been unanimously adopted for the Pacific population.
In the Pacific, their populations declined over the past 30 years. While harvests were high and may not have been sustainable in some areas, declines in abundance in both fished and unfished areas suggest that fishing played a limited role in the population collapse. The decline was generally attributed to a warming of the waters off the coast of Alaska. Warming is believed to have direct effects on shrimp reproduction success while also favoring production of fishes that prey on shrimp.
Northern shrimp abundance remains low over the western and central Gulf of Alaska, and the historically important trawl fisheries for northern shrimp remain closed.
The primary factors that can threaten northern shrimp populations are climate changes, ocean acidification and overfishing.
In the Northern Atlantic, the Gulf of Maine fishery targets females and is managed through an interstate agreement between the states of Maine, New Hampshire and Massachusetts, via the Atlantic States Marine Fisheries Commission. The Fishery Management Plan for Northern Shrimp was approved in 1986 and Amendment 1 in 2004.
The Northern Shrimp Technical Committee provides annual stock assessments and related information to ASMFC . Management decisions of the stock are then made annually. In the Atlantic, the fishing season is generally from December through May.
Like other arthropods, shrimps have no internal skeleton, being protected instead by an exoskeleton which must be repeatedly shed as the animal grows, similar to lobster.And like lobster, they are a favorite food in the northeast.
Global coldwater shrimp production is dominated by landings of northern shrimp, pandalus borealis, in the North Atlantic. This species accounted for about 80 percent of coldwater shrimp landings in the mid 1980s through 2000. U.S. shrimp imports have risen steadily from about 78 percent of total supply in the mid 1990s to almost 90 percent of the nearly 770 thousand metric tons in 2003.
Canada supplies roughly half of the coldwater shrimp in the United States. Atlantic shrimp have dominated landings for at least the last 15 years, accounting for 96 percent of Canadian landings between 1999 and 2003. In contrast, New England supplies only a few percent of the total U.S. supply. Approximately 75 percent of Canadian production is of northern shrimp. All sources combined, this species makes up perhaps 40 percent of the coldwater shrimp on the U.S. market.
Pacific shrimp fisheries off the U.S. and British Columbia reflect the greater diversity of coldwater species available in commercially viable abundance in the Northeast Pacific compared to the Northwest Atlantic. Shrimp fisheries occur off the entire west coast from Southern California to the Aleutians, but the target species and gears used vary between and within states.