Fish
Marbled Rockcod
Notothenia rossii · also called marbled notothen
Once the primary target of the earliest large-scale Southern Ocean fishery, a marbled rockcod’s population around South Georgia collapsed by more than 99 percent within a few short years, a decline so severe the species still has not recovered decades later.
Overview
The marbled rockcod, Notothenia rossii, is a Vulnerable fish native to ocean and polar habitat around South Georgia and other subantarctic islands of the Southern Ocean. Its history as the primary target of the earliest Antarctic commercial fishery, its catastrophic population collapse, and its slow ongoing recovery make it one of the more cautionary fish species found anywhere in Antarctic waters.
A fishery’s first casualty
Long before krill or toothfish fisheries developed, the marbled rockcod was the first Southern Ocean fish species exploited at industrial scale, a pressure so intense around South Georgia that populations there have never come close to recovering even decades later.
Status
Vulnerable, with populations around South Georgia remaining far below historical levels after a collapse of over 99 percent, and little recovery documented despite decades of reduced fishing pressure.
Marbled Rockcod: common questions
Why was the marbled rockcod so heavily fished?
This species was the primary target of the earliest large-scale Southern Ocean commercial fishery, heavily exploited around South Georgia beginning in the late 1960s before other Antarctic fisheries developed.
How badly did the marbled rockcod population decline?
This species experienced a population collapse of over 99 percent around South Georgia following intense early fishing pressure, one of the most severe documented declines of any Southern Ocean fish species.
Has the marbled rockcod recovered since fishing pressure eased?
No, this species has still not recovered to anything near its historical abundance around South Georgia, despite decades having passed since large-scale commercial fishing for the species ceased.
Where do young marbled rockcod live?
Juveniles of this species shelter and feed among coastal kelp beds before moving to deeper water as adults, a habitat shift shared with some other notothenioid fish species.