Aquatic Species at Risk – North Pacific Spiny Dogfish

Description
Habitat
Threats
Further Information
Scientific Information

Description
North Pacific spiny dogfish (Squalus suckleyi) is an easily identifiable small shark, with spines in front of both dorsal fins. Its colouration is typically grey-brown with irregular white spots on its sides and back. After the longest gestation of any known vertebrate (18-24 months), an average of six pups are born live in the winter. Females mature at approximately 35 years and the generation time is estimated at 51 years.

Image Credit: Jennifer Stone

Habitat
Spiny dogfish are found on the continental shelf, from the intertidal zone to the shelf slope, in temperate and boreal waters. Waters off British Columbia comprise a large portion of the core range of spiny dogfish in the northeast Pacific with concentrations in the Strait of Georgia, west coast Vancouver Island, and in Hecate Strait. Research has shown some size and sex segregation, which may reflect habitat preferences; as well, there is a seasonal shift in distribution thought to be driven by temperature preference. Habitat is not believed to be a direct factor driving population trends.

Threats
Globally and in Canada, overfishing is considered the only imminent threat to spiny dogfish at a population level. Life history characteristics of long gestation, slow growth rate, late age of maturity, slow population growth-rate in ideal conditions, low fecundity, long lifespan, and sex- and size-segregated aggregations make the spiny dogfish highly susceptible to overfishing.

Further Information:
The spiny dogfish plays an important role in both natural and human systems. This species has been killed for more varied purposes than any other fish in Canada. Its body oils have been used for industrial lubricants, lighting fuel, and vitamin A, and its flesh for fertilizer, food and fishmeal; its fins have entered the international shark fin trade; and it has been the subject of directed eradication programs due to its ‘nuisance’ factor in commercial fisheries.

For more information, please visit the Pacific Region SARA Consultation website or the SARA Registry.

Scientific Information:

Scientific name: Squalus suckleyi
SARA Status: None
COSEWIC Status: Special Concern (November 2011)