Winter preconditioning determines feeding ecology of Euphausia superba in the Antarctic Peninsula

2015 ◽  
Vol 519 ◽  
pp. 89-101 ◽  
Author(s):  
CS Reiss ◽  
J Walsh ◽  
ME Goebel
Keyword(s):  
Antarctic Peninsula ◽  
Feeding Ecology ◽  
Euphausia Superba ◽  
The Antarctic

Length and age at maturity of Antarctic krill

1994 ◽  
Vol 6 (4) ◽  
pp. 479-482 ◽  
Author(s):  
V. Siegel ◽  
V. Loeb
Keyword(s):  
Antarctic Peninsula ◽  
Sexual Maturity ◽  
Antarctic Krill ◽  
Euphausia Superba ◽  
Knife Edge ◽  
Age At Maturity ◽  
Growth Season ◽  
The Third ◽  
Age Class ◽  
The Antarctic

Data from several summer research cruises in the Antarctic Peninsula region were analysed to calculate length (L50) and age at maturity for the Antarctic krill, Euphausia superba. Length at maturity L50 is defined as the length at which 50% of the krill stock attains sexual maturity. L50 values of 34.65–35.91 mm for female krill are the best estimates for the peak spawning season. Males attain sexual maturity later at L50 values of 43.35–43.71 mm. Length at maturity and length at first spawning are identical for krill. Comparisons with mean length-at-age data show that females mature in the third growth season (age class 2+), while males reach maturity in the fourth year (age class 3+). Both sexes show ‘knife-edge maturity’.

Fishing down the food web of the Antarctic continental shelf and slope

Polar Record ◽  
2013 ◽  
Vol 50 (1) ◽  
pp. 92-107 ◽  
Author(s):  
David G. Ainley ◽  
Daniel Pauly
Keyword(s):  
Southern Ocean ◽  
Food Web ◽  
Antarctic Peninsula ◽  
Continental Margin ◽  
Marine Mammals ◽  
Marine Ecosystem ◽  
Euphausia Superba ◽  
The Commons ◽  
By Catch ◽  
The Antarctic

ABSTRACTThe history of biotic exploitation for the continental margin (shelf and slope) of the Antarctic Large Marine Ecosystem (LME) is reviewed, with emphasis on the period from 1970 to 2010. In the Antarctic Peninsula portion, marine mammals were decimated by the 1970s and groundfish by the early 1980s. Fishing for Antarctic krill Euphausia superba began upon the demise of groundfish and now is the only fishing that remains in this region. Surveys show that cetacean and most groundfish stocks remain severely depressed, harvest of which is now prohibited by the International Whaling Commission and the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). On the other hand, krill fishing in this region is underway and in recent years has contributed up to 72% of the Southern Ocean catch, depending on fishing conditions and the CCAMLR conservation measures in force. Elsewhere along the Antarctic continental margin, marine mammals were also severely depleted by the 1970s, followed directly by relatively low-level fisheries for krill that continued until the early 1990s. Recently in these areas, where fin-fishing is still allowed, fisheries for Antarctic toothfish Dissostichus mawsoni have been initiated, with one of this fish's main prey, grenadiers Macrourus spp., being taken significantly as by-catch. Continental margin fishing currently accounts for ~25% of the total toothfish catch of the Southern Ocean. Fishing along the Antarctic continental margin, especially the Antarctic Peninsula region, is a clear case of both the tragedy of the commons and ‘fishing down the food web’.

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