Cusk (Brosme brosme)
Photo: NOAA Northeast Region
Did You Know?
- Cusk is the only fish in its genus Brosme.
ESA Species of Concern - Atlantic-Gulf of Maine
|up to 20 pounds (9 kg)|
|up to 3 feet (1 m)|
|light grey with hints of brown to a dull reddish brown that transitions to a dirty white on the belly, a single chin "barbel" and single dorsal fin|
|about 15 years|
|crustaceans, fishes, and echinoderms|
|solitary animals, sometimes found in small groups; they spawn in spring to early summer|
The cusk is a very unique species of fish and the only one in its taxonomic genus of Brosme. Cusk can be up to 3 feet (1 m) in length and weigh up to 20 pounds (9 kg). They are characterized by a single chin "barbel" and single dorsal fin. Their upper body ranges in color from a light grey with hints of brown to a dull reddish brown that transitions to a dirty white on the belly.
Cusk are relatively slow-growing and late-maturing. Fifty percent of fish mature at approximately 1.5 feet (.5 m) in length when they are about 5 to 6 years old. Females generally mature later than males. The maximum age of this species is believed to be greater than 14 years.
Cusk spawn in spring and early summer. Eggs initially rise to the surface where hatching and larval development take place. Juveniles move to the bottom at 2 inches (5 cm) in length and become sedentary and solitary.
The cusk diet consists primarily of various species of crustaceans, fishes, and echinoderms. Cusk are solitary or occur in small groups.
A declining population trend has been evident since the late 1960s. All abundance indices remained at or close to record-low levels from 1985 through 2002. NOAA's Northeast Fisheries Science Center biomass index for cusk was near zero in 1998. In the early 1970s, individual fish weight averaged 7 lbs (3 kg) but declined by 50% to 1.5 kg (3 lbs) through the late 1990s. Landings and survey indices have dropped considerably from 1984 to 2004. The ratio of landings to biomass estimates has been increasing since 1986, which implies increased exploitation over time.
The catch per unit effort from 1970-2001, or just over 3 cusk generations, declined by about 90% while population estimates for cusk greater than 20 inches (0.5 m) in the same time frame showed a 96% decline (Committee on the Status of Endangered Wildlife in Canada (COSEWIC 2003).
- Commercial fishing is the primary factor for the decline in cusk abundance. Fisheries use four principal gears to catch cusk:
- line trawl
- otter trawl
- gill net
- "bycatch" in longline fisheries directed at Atlantic halibut, cod, haddock and pollock also threaten cusk
|Notice of Initiation of a Status Review under the Endangered Species Act (ESA)||72 FR 10710||03/09/2007|
Updated: January 21, 2015