Polarstern catches five tons of Marbled Antarctic Cod

One of Polarstern’s biggest fish catch in 24 years of research in Antarctic waters. New hope for commercial fisheries? Quite the opposite, a good catch doesn’t necessarily mean that depleted stocks have recovered.

Five tons of marbled Antarctic cod (Notothenia rossii), now that was surely a big surprise to scientists and crew alike considering that previous and subsequent hauls barely ever reaped such plentiful harvests. the last comparable catch of 5.6 tons Antarctic cod was done in november 1983 round Elefant Island. Their shimmering silver and dark blue bodies, which can grow up to 70cm, were piled on the aft deck of Polarstern. In combination with previous stock assessments, fisheries biologists onboard interpreted the catch as a sampling of a discrete, small-scale aggregation of this fish species.

There are two hypotheses to explain the observed dense aggregation: 1. krill, the main prey of marbled Antarctic cod, aggregate to form a band of dense shoals in close vicinity to its preferred habitat; and 2. certain seafloor topographies, such as canyons or cliffs may be conducive to its aggregation. The tendency to shoal made them an easy target for commercial fisheries in the past. After depletion of marbled Antarctic cod stocks the "Convention on the Conservation of Antarctic Marine Living Resources" (CCAMLR) decided to ban fishing activities. Resuming commercial fisheries could easily lead to stocks being overfished. Germany, represented by the Federal Research Centre for Fisheries, is constantly providing results to the responsible CCAMLR working group to prevent overexploitation of Antarctica’s fish stocks.

Bremerhaven, 27 December 2006

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Notes for editors: Your media contact at Alfred Wegener Institute is Dr Angelika Dummermuth (+49(0)471 4831 1742; e-mail: medien@awi.de).

The Alfred Wegener Institute for Polar and Marine Research (AWI) conducts research in the Arctic, Antarctic and in oceans of mid and high latitudes. The AWI coordinates polar research in Germany, and provides important infrastructure, such as the research icebreaker Polarstern and stations in the Arctic and Antarctic, for international science organisations. The AWI is one of 15 research centres of the 'Helmholtz-Gemeinschaft' (Helmholtz Association), the largest scientific organization in Germany.