A mass balance calculation was made for the floating part of Byrd Glacier, using 1978–79 ice elevation and velocity data, over the 45 km of Byrd Glacier from its grounding line to where it leaves its fjord and merges with the Ross Ice Shelf. Smoothed basal melting rates were relatively uniform over this distance and averaged 12 ± 2 m yr−1.

The marine resources of the Antarctic region are of global significance. In managing Southern Ocean marine resources, especially fisheries, the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) has adopted principles that aim: to balance harvesting and conservation; to protect the needs of dependent species, and to avoid changes that are irreversible in 20–30 years. CCAMLR has pioneered ecosystem approaches to fishery and environmental management, through the incorporation of precaution and uncertainty into its management procedures and by establishing an ecosystem monitoring programme using indicator species and processes. This pioneering application of precautionary and ecosystem approaches in the management of harvesting has met with some success, notably in applying conservative yield models for toothfish and krill stocks and in establishing strict rules for undertaking new and exploratory fisheries. However, toothfish management has been recently compromised by Illegal, Unreported and Unregulated (IUU) fishing which is driven by forces outside the Southern Ocean. Southern Ocean harvestable resources are also subject to other global forces such as environmental changes, and their management systems remain very vulnerable to rapid shifts in worldwide fishery economics, and to inadequate management in adjacent areas, particularly high seas. CCAMLR needs quickly to develop the basis of more flexible and effective management to cater for rapid shifts in capacity and demand. The complementary task, however, is to raise the management standard of other Regional Fisheries Management Organisations (RFMOs) to those of CCAMLR if global high seas marine resources are to be sustainable for the rest of this century.