Northern Shrimp | Oceana Canada

Canadian Marine Life Encyclopedia

Northern Shrimp

Pandalus borealis

Also known as

Northern prawn, deepwater prawn, pink shrimp

Distribution

Northwest Atlantic and northeast Pacific Ocean

Écosystèmes/habitats

Soft bottoms with features that provide protection

Feeding Habits

Foraging omnivore

Conservation Status

Not listed

Taxonomie

Subphylum Crustacea (crabs, shrimps, and relatives); Family Penaeidae (prawns)

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Northern shrimp, also commonly known as northern prawn, are a sequential hermaphrodite. This is a term used for animals that start their life as one sex and change to the other later in life. In the case of northern shrimp, they are born as males and become females at around four or five years of age. This type of hermaphroditism is common in many other species of fish and gastropods (like snails and slugs). The common clownfish, like Nemo from the movie Finding Nemo, is another species that exhibits sequential hermaphroditism. 

Northern shrimp are a medium-sized shrimp. They are a pinkish red colour with no banding, unlike striped shrimp which are also found in Canada. They are slender and have a smooth body surface that is made up of a thin, hard outer shell, called an exoskeleton, which they periodically moult, or shed, in order to grow. They have several small spines on their rear abdominal segments, as well as on their rostrum, which is a horn-like projection that sticks out between their eyes. On average Northern shrimp grow to be about 5-10 cetimetres in length; however they have been known to grow as large as 15-16 centimetres long. 

Northern shrimp breed in the fall and reach sexual maturity as males at around age two. The male will grasp onto a female and transfer a packet of sperm to the underside of her abdomen. The female will then release eggs, which become fertilized as they pass over the sperm packet and onto the hair-like structures on the underside of her legs. The eggs remain attached throughout the winter as they develop and are protected by the overhanging abdominal plates of the female. When the eggs are ready to hatch in the spring and early summer, the female will fan water under her abdomen using her legs, which releases the larvae.  Between 2,000 and 4,000 newly hatched larvae will be released by the female, which will swim throughout the water column for the majority of their first summer. At the end of the summer, after they have moulted their exoskeleton several times, they will settle to the ocean floor to begin their juvenile stage. At about two years of age, they will moult again and become sexually mature males. After breeding for at least one or two years as males, they will gradually transform permanently into females, typically during their fourth summer. Northern shrimp will typically live to around six years of age, however they are thought to live longer than eight years in the most northern parts of their range. 

Fished in both the Pacific and the Atlantic oceans, the commercial fishery for northern shrimp in the Atlantic began in the 1960s and 1970s, although the trawl fishery did not expand to its full potential until it was able to overcome bycatch (incidental catch) of groundfish by introducing the Nordmore grate in the early 1990s. The Nordmore grate fits into the opening of a trawl and only allows small species, like shrimp, to fit between the rungs of the grate into the net, while larger species, like groundfish and sea turtles, are excluded and directed toward an escape opening in the net. Today, Canada leads the way globally with exports of cold water shrimp, exporting more than any other country in the world. Shrimp is Canada’s fourth most valuable seafood export. Northern shrimp is by far the most abundant species of shrimp, at least in Atlantic Canada, with about 97 per cent of the commercial fishery in the region represented by Northern shrimp. 

In the Pacific Ocean, the catch of northern shrimp in the Pacific prawn and shrimp fishery is negligible, with higher catches of spot prawn, smooth pink shrimp and sidestripe shrimp observed in the region. The inshore fishery operates from spring to fall, while the offshore fishery operates all year long. The fishery is highly regulated and managed in a fairly sustainable manner, taking into account scientific information on population size when establishing Total Allowable Catches (TACs). 

Northern shrimp caught by trawl in Eastern Canada is listed as sustainable by some certifications but there is concern about the use of bottom trawling and its impact on habitat. Northern shrimp caught by trap in eastern Canada, on the other hand, is listed as sustainable by all seafood certifications and is widely accepted as a sustainable seafood option. 

Northern shrimp have not been assessed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), and therefore have not been listed under the Species at Risk Act (SARA). However, under Fisheries and Oceans Canada’s Precautionary Approach Framework, most populations are assessed as healthy. The only exceptions are the populations off the north coast of Newfoundland and in the Hawke channel (Shrimp Fishing Area (SFA) 6), which has been assessed as cautious, and the population in the Hudson Strait, which lacks sufficient data to be properly assessed so it is listed as unknown. Current estimates show that the majority of Northern shrimp populations in eastern Canada have declined slightly over the past few years, although they are still considered to be in a stable condition.