Summer diet of Weddell Seals (Leptonychotes weddelli) in the eastern and southern Weddell Sea, Antarctica

Abstract

Summary. Stomach and intestine samples from 21 adultWeddell seals were used to study the diet of these seals from the eastern and southern Weddell Sea coast from January to February 1983 and 1985. Fish and Woyciechowski 1981). Quantitative data on food intake as well as data on size of dominant prey organisms taken by individual Weddell seals are sparse and urgently required for different areas and seasons, before more realistic assessments of food consumption can be made.This study is the first report on the summer diet of Weddell seals along the high Antarctic Weddell Sea coast. The eastern and southern parts of this area are characterized by both shallow and deep water zones with grounded or floating ice shelf masses and permanent eroding ice edges. During summer, when the fast ice cover breaks off close to the ice shelf edge, the resting sites of Weddell seals become reduced and the animals are compelled to occupy drifting floes or concentrate in the inlets, where remaining multiyear sea ice provides a permanent habitat. Due to the almost open waters, the hunting range and success of Weddell seals is not influenced by tile availability of breathing holes and tide cracks, but probably more by the distribution of sea ice and the distribution and abundance of dominant prey organisms along the ice shelf barrier during the short summer.

Fine-scale three-dimensional spatial use by diving, lactating female Weddell seals Leptonychotes weddellii

“…The seals also take large Dissostichus mawsoni from deep in the water column (Davis et al 1999). Elsewhere in Antarctica, Weddell seals feed on a range of prey including pelagic P. antarcticum, Trematomus spp., decapod crustaceans and cephalopods (Clarke & MacLeod Plotz 1986, Plotz et al 1991, Green et al 1995. The diet varies spatially and temporally (Green & Burton 1987), suggesting that the seals are opportunistic feeders exploiting a large range of prey and habitats.…”

Cephalopod remains in scats of Weddell seals (Leptonychotes weddellii) at Cape Shirreff, South Shetland Islands, Antarctica

“…Bertram 1940;Dearborn 1965;Davis et al 1982;Testa et al 1985;Plötz 1986;Casaux et al 2006Casaux et al , 2009. Despite the low number of scats collected from only 1 month a long time ago at Cape Shirreff, the order Octopoda accounted for 100 % of the cephalopod component.…”

“…The ability to dive below 700 m allows Weddell seals to forage in both benthic and pelagic habitats over the Antarctic continental shelf (Testa 1994;Lake et al 2003). The diet of Weddell seals has been studied in East Antarctica (Green and Burton 1987;Green et al 1995;Lake et al 2003), the Antarctic Peninsula (Casaux et al 2006;Daneri et al 2012), the Weddell Sea (Plötz 1986;Plötz et al 1991), the Ross Sea (Dearborn 1965;Calhaem and Christoffel 1969;Davis et al 1982;Castellini et al 1984;Testa et al 1985;Green and Burton 1987;Burns et al 1998) and the South Shetland Islands (Lipinski and Woyciechowski 1981;Clarke and MacLeod 1982;Cassaux et al 1997). The diet has been reported to consist of nototheniid fishes, cephalopods, prawns and other small invertebrates.…”

Capital Expenditure and Income (Foraging) during Pinniped Lactation: The Example of the Weddell Seal (Leptonychotes weddellii)

“…Classically, the diet of the Weddell seal has been examined by stomach content analysis (Bertram, 1940;Dearborn, 1965;Plötz, 1986;Plötz et al, 1991), but lethal methods are no longer employed, and gastric lavage of adults requires extensive restraint or chemical immobilization. Scat analysis can provide information on those prey that have identifi able indigestible parts (Burns et al, 1998;Lake et al, 2003) or even residual prey DNA (Casper et al, 2007) in the scats.…”