The uncertainty surrounding how different species will respond to these challenges, given their varying life histories, environmental dependencies, and resiliencies, necessitates regular assessment to inform conservation and management decisions. Fisheries and climate change, coupled with related local and global drivers such as pollution and sea ice change, have the potential to produce synergistic impacts that compound the risks to Antarctic fish and squid species. Climate variability may impair the migratory response of these species to environmental change, while imposing increased pressures on recruitment. These trends are expected to result in a redistribution of species based on their tolerances to different temperature regimes. Parts of the Southern Ocean are experiencing ocean-warming, such as the West Antarctic Peninsula, while other areas, such as the Ross Sea shelf, have undergone cooling in recent years.
Fisheries currently remain the major local driver of change in Southern Ocean fish productivity, but global climate change presents an even greater challenge to assessing future changes. Uncertainty about the population dynamics of target species and ecosystem structure and function more broadly has necessitated a precautionary, ecosystem approach to managing these stocks and enabling the recovery of depleted species. In addition to krill exploitation, the comparatively high commercial value of Antarctic fish, particularly the lucrative toothfish, drives fisheries interests, which has included illegal fishing. Adaptations such as antifreeze glycoproteins, lipid-retention, extended larval phases, delayed senescence, and energy-conserving life strategies equip Antarctic fish and squid to withstand the dark winters and yearlong subzero temperatures experienced in much of the Southern Ocean. They comprise a diverse array of species uniquely adapted to the extreme habitats of the region. Fish and squid make up a significant portion of the biomass within the Southern Ocean, filling key roles in food webs from forage to mid-trophic species and top predators. Southern Ocean ecosystems are globally important and vulnerable to global drivers of change, yet they remain challenging to study. We do this by undertaking a qualitative, yet comprehensive, review of the published literature to identify their potential advantages, limitations, and their relevance to monitoring efforts. The aim of the present report is to provide a comparative assessment of commonly used pelagic sampling methods. There is thus an urgent need to synthesise and compare these methods to determine how they can best support and strengthen the empirical evidence base available for implementing marine monitoring programmes. Protocols for choosing optimal combinations of methods for a given region, taxonomic/indicator group, or habitat remain generally unavailable. drifting baited videography, environmental DNA, unmanned aerial vehicles) with various degrees of autonomy and sensory capabilities is revolutionising the way we quantify biophysical processes and observe wildlife in remote habitats. While these remain a critical component of biological and oceanographic research today, a rapidly increasing array of innovative technologies (e.g. Early pelagic studies relied heavily on capture sampling using nets. Whilst pelagic waters present fascinating opportunities for ecological investigation, their extreme horizontal, vertical and temporal patchiness, as well as the huge size range of organisms inhabiting the open ocean, also pose important methodological challenges for sampling. This can be challenging given the smorgasbord of modern survey tools currently available, most of which differ widely in costs, capabilities, mobilisation constraints, resolution, or sensitivity, and are evolving rapidly without always being critically evaluated or compared. Faced with mounting pressures to build accountability, managers and policy advisors must now more than ever make monitoring investment decisions that are both impactful and cost-effective. Increasingly stringent conservation budgets, however, are placing a strong emphasis on strategic resource allocation. Monitoring its dynamics is fundamental to understanding and reporting on how the ocean is responding to human pressures and global environmental change. Australia’s Exclusive Economic Zone (EEZ) is the third largest maritime territory in the world.
0 kommentar(er)
