Description: Exploitation of Southern Ocean marine resources began more than 200 years ago with the massive hunt for seals and whales. In the 1960s/70s, fisheries for finfish and krill entered Southern Ocean waters. Within a few years many fish populations were heavily overfished and dramatically depleted, and some of these stocks still did not recover. Today, fish stocks and fisheries activities are managed and monitored by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) which was established in 1982 to ensure sustainable exploitation and protection of the delicate marine ecosystem. Current target species include Mackerel icefish (Champsocephalus gunnari), Patagonian as well as Antarctic toothfish (Dissostichus eleginoides and D. mawsoni) and Antarctic krill (Euphausia superba). Most of these species are vulnerable to overfishing due to slow growth, late age at maturity, and rather low fecundity. This vulnerability might increase, as Southern Ocean living communities are currently also faced with alterations of their environment due to climate change, such as increasing water temperatures and decreasing sea ice. Species, including the ones targetted by fisheries, are well-adapted to their particular environmental conditions and are believed to be highly sensitive to changes because of their cold-adapted physiology, their life history traits, and their direct or indirect dependence on sea ice. The species will be exposed to several stressors at the same time, and fishing pressure, direct abiotic forcing and changes mediated via the food web might act synergistically and result in significant population declines. In particular the strongly sea ice-dependent Antarctic krill, a key species in the food web, might be adversely affected. Fish species seems to have low tolerance towards higher water temperatures and may thus, in the long run, be replaced by lower latitude species.

Description: The global population is growing and the demand for food and energy is steadily increasing. Coastal space all over the world becomes increasingly limited and near-shore resources are often already heavily exploited. The use of offshore regions may provide new opportunities, but also involves major challenges such as the development of designs and technologies suitable for offshore condition. The floating TROPOS ‘Green & Blue’ modular multi-use platform concept introduced in this chapter is especially designed for offshore conditions and provides solutions for the problems and obstacles involved in “moving offshore”. The Green & Blue platform concept integrates fish and algae aquaculture with a wind farm. The floating multi-use approach allows for platform operation in deep waters and the promotion of synergies such as joint logistics, shared infrastructure and services, thereby making the use of offshore resources viable and profitable.

Description: Pleuragramma antarctica is the dominant forage fish of the coastal Antarctic, exhibiting a circumantarctic distribution and a well documented abundance in all shelf environments, from the high Antarctic Weddell and Ross Sea systems, to the milder waters of the western Antarctic Peninsula (WAP) shelf. Rapid regional warming on the WAP has produced a dichotomy in annual weather patterns between the high Antarctic systems and the WAP, resulting in swiftly rising midwinter air temperatures and fewer sea ice days during the annual winter cycle on the WAP, and little change in the Ross and Weddell Seas. The WAP shelf thus provides a model system for examining the potential effects of climate warming on an important Antarctic species. Pleuragramma’s life history is characterized by slow growth, late maturity, a high reproductive investment and an association with coastal sea ice for spawning and larval development. All those features will allow the species to weather episodic annual failures in recruitment, but not long term change. Most effects of the increasing temperature associated with climate change will be indirect ones, as temperatures will not increase to the point where they are physiologically life-threatening in the short term. A recent survey of Pleuragramma distribution on the WAP shelf revealed a large break in its historical distribution in shelf waters, suggesting a collapse in the local population of silverfish there. The break occurred in the area that has been most heavily impacted by rapid regional warming: the northern mid-shelf including Anvers and Renaud Island. It may be that the multi-faceted effects of climate change are already at work in its local disappearance.