Managing fishery development in sensitive ecosystems: identifying penguin habitat use to direct management in Antarctica

Abstract

2018. Managing fishery development in sensitive ecosystems: identifying penguin habitat use to direct management in Antarctica. Ecosphere 9(8):Abstract. In the Southern Ocean, the at-sea distributions of most predators of Antarctic krill are poorly known, primarily because tracking studies have only been undertaken on a restricted set of species, and then only at a limited number of sites. For chinstrap penguins, one of the most abundant krill predators breeding across the Antarctic Peninsula, we show that habitat models developed utilizing the distance from the colony and the bearing to the shelf-edge, adjusting for the at-sea density of Pygoscelis penguins from other colonies, can be used to predict, with a high level of confidence, the at-sea distribution of chinstrap penguins from untracked colonies during the breeding season. Comparison of predicted penguin distributions with outputs from a high-resolution oceanographic model shows that chinstrap penguins prefer nearshore habitats, over shallow bathymetry, with slow-flowing waters, but that they sometimes also travel to areas beyond the edge of the continental shelf where the faster-flowing waters of the Coastal Current or the fronts of the Antarctic Circumpolar Current occur. In the slow-moving shelf waters, large penguin colonies may lead to krill depletion during incubation and chick-rearing periods when penguins are acting as central place foragers. The habitats used by chinstrap penguins are also locations preferentially used by the commercial krill fishery, one of the last under-developed marine capture fisheries anywhere on the planet. As it develops, this fishery has the potential to compete with chinstrap penguins and other natural krill predators. Scaling our habitat models by chinstrap penguin population data demonstrates where overlap with the fishery is likely to be most important. Our results suggest that a better understanding of krill retention and krill depletion in areas used by natural predators and by the krill fishery are needed, and that risk management strategies for the fishery should include assessment of how krill movement can satisfy the demands of both natural predators and the fishery across a range of spatial and temporal scales. Such information will help regional management authorities better understand how plausible ecosystem-based management frameworks could be developed to ensure sustainable co-existence of the fishery and competing natural predators.

Long-term observations from Antarctica demonstrate that mismatched scales of fisheries management and predator-prey interaction lead to erroneous conclusions about precaution

“…However, penguins foraging from our monitoring sites overlap with the krill fishery in areas where surface currents are relatively weak (Fig. 3c, with panel c adapted from 26 ), and habitat models suggest that chinstrap penguins throughout the AP and South Orkney Islands forage in slow moving water 39 . Second, the ongoing recovery of whale populations in the Southern Ocean has the potential to impact penguin populations 21 .…”

Identification of marine Important Bird and Biodiversity Areas for penguins around the South Shetland Islands and South Orkney Islands

“…Second, we removed the “TripSplit” step (Lascelles et al., ), as identifying individual foraging trips, especially the short ones, can be virtually impossible with PTT‐Argos‐quality data for Pygoscelis penguins because of the infrequency of observed positions, especially for older datasets. Thus, instead of using different trips as independent observations, we now use all at‐sea location data for each individual bird without splitting into trips (Trathan et al., ); this increases the quality of the core areas estimated for each individual and minimizes the risk of pseudoreplication due to individual fidelity to specific foraging sites (Wakefield et al., ). Third, we evaluated a range of kernel smoothing factors ( h‐value ).…”

Translating Marine Animal Tracking Data into Conservation Policy and Management

“…Tracking data from Pygoscelis penguins have revealed predictable feeding areas and highlighted areas of potential competition with the regional fishery for Antarctic krill (Euphausia superba) at the Antarctic Peninsula and at nearby archipelagoes [14,15]. The data from Adélie penguins (Pygoscelis adeliae) were used to help create the South Orkney Islands southern shelf MPA, the first MPA designated entirely within internationally managed waters (with approximately 94,000 km 2 ), which was made a no-take MPA by CCAMLR in 2009 (example 3).…”