A Spatially Explicit Model of the Antarctic Krill Fishery Off the South Shetland Islands

Abstract

We show the development of a spatially explicit ecosystem model for the Euphausia superba fishery in the South Shetland Islands area (Antarctic Peninsula). We generated a virtual ecosystem, using a spatial automaton-geographic information system technique, to study management scenarios. We used literature data to generate the advection field, the initial krill biomass, and the distribution and size of penguin colonies in the area. Parameters for the fishing fleet were extracted from analysis of Chilean krill-fishing vessels. The model assumes that krill are passive current drifters and that penguin foraging occurs in areas close to their colonies. We analyzed the effect that a simulated 20-vessel fishing fleet would have on the availability of prey, considering the krill flux due to advection. The results show that it would be reasonable to manage the krill fishery in the South Shetland Islands as an interconnected set of ecotrophic modules, allocating the fleet downstream from the main penguin foraging sector.

Interannual spatial variability of krill (Euphausia superba) influences seabird foraging behavior near Elephant Island, Antarctica

“…Krill is an important resource for birds, and is also a resource targeted by commercial fisheries (May et al. , 1979; Everson and Goss, 1991; Mangel, 1994; Marin and Delgado, 2001). Successful management and conservation of resources requires description of spatial pattern and predicting how organisms respond to it (Cairns, 1992; Mangel, 1994; Furness and Camphuysen, 1997; Reid et al.…”

“…, 2004c). Potential impacts on krill‐dependent predators through commercial harvesting of krill should be addressed by incorporating the foraging demand of predators (Mangel, 1994; Mangel and Switzer, 1998; Marin and Delgado, 2001). Based on our study, we urge that future modeling work emphasize the impact of krill patchiness in relation to predator foraging demand.…”

“…Changes in the spatial distribution of krill may have significant impacts on foraging and reproductive success of krill‐dependent predators (Agnew and Phegan, 1995; Marin and Delgado, 2001). During the predator’s breeding season, the adult animals depend on locating sufficient amounts of krill to support the energetic needs of themselves and their offspring.…”

Spatial association between hotspots of baleen whales and demographic patterns of Antarctic krill Euphausia superba suggests size-dependent predation

“…The spatial structure of whale foraging grounds near the SSI has significant implications for management of the Antarctic krill fishery (Marin & Delgado 2001, Jones & Ramm 2004) and conservation of baleen whales (Mori & Butterworth 2004, Kaschner et al 2006. The krill fishery is managed by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR).…”

“…Despite their ecological importance, past exploitation, and dominant role in the ecosystem, rather little is known about the foraging habitats of each species of baleen whale near the South Shetland Islands, Antarctica ( Fig. 1), a region known for its elevated krill biomass (Laws 1977, Siegel 1988, Loeb et al 1997, Reilly et al 2004, Reiss et al 2008, active krill fishery (Marin & Delgado 2001, Jones & Ramm 2004, and historical whaling (Mackintosh 1965, Laws 1977. Whales are often associated with krill (Reid et al 2000, Murase et al 2002, Friedlaender et al 2006, and there is evidence that whales exhibit preferences for ABSTRACT: We examined the spatial association between baleen whales and their principal prey, Antarctic krill Euphausia superba near the South Shetland Islands (Antarctic Peninsula) using data collected by the US Antarctic Marine Living Resources (AMLR) program during January surveys from 2003 through 2007.…”