Southern ocean fisheries: managing harvests of marine life
Despite its inhospitality and relative remoteness, the Southern Ocean has not escaped the immediate, unrestrained and unregulated exploitation accompanying newly discovered biological resources. Historically, opportunistic harvesting of seabirds, eggs, seals and fish occurred to supplement the food of ship-based expeditions. However, from the late 1800s onwards four major phases of harvesting progressively targeted seals, whales, finfish and krill (Euphausia superba). This culminated in severe depletion of Antarctic fur seals and some whale species, and in the case of blue whales and finfish, subsequent regulation did not compensate for their near extinction, or for the decimation that resulted in further exploitation being uneconomic. While some seal populations have recovered (e.g. fur seals at South Georgia) and some whale populations (e.g. southern minke whale) may have benefited from exploitation of larger species, there is still widespread concern about the ecological consequences of unsustainable and heavy exploitation of marine life in the Southern Ocean. Many Southern Ocean species are slow-growing and long-lived. They are also slow to repopulate when numbers are depleted. For most species, very little is known about their detailed biology and life histories. These qualities and other considerable uncertainties affect management efforts aimed at ensuring the sustainable exploitation of Southern Ocean marine living resources in general, and the potentially large krill resource in particular.