Significant intra-annual variability in krill distribution and abundance at South Georgia as revealed by multiple acoustic surveys during 2000/01

Three separate acoustic surveys of Antarctic krill (Euphausia superba) were conducted around South Georgia in the 2000/01 season: in October 2000 (early-season); during late December/early January 2000/01 (mid-season), and in March 2001 (late-season). The surveys were the first in a newly planned fi...

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Main Authors: Brierley, Andrew Stuart, Goss, C, Grant, SA, Watkins, JL, Reid, K, Belchier, M, Everson, I, Jessop, MJ, Afanasyev, V, Robst, J
Format: Article in Journal/Newspaper
Language:English
Published: 2002
Subjects:
Online Access:https://risweb.st-andrews.ac.uk/portal/en/researchoutput/significant-intraannual-variability-in-krill-distribution-and-abundance-at-south-georgia-as-revealed-by-multiple-acoustic-surveys-during-200001(a7e24790-418b-4fe8-8afb-80ae96e4ed90).html
http://www.scopus.com/inward/record.url?scp=0346108602&partnerID=8YFLogxK
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spelling ftunstandrewcris:oai:risweb.st-andrews.ac.uk:publications/a7e24790-418b-4fe8-8afb-80ae96e4ed90 2023-05-15T13:45:52+02:00 Significant intra-annual variability in krill distribution and abundance at South Georgia as revealed by multiple acoustic surveys during 2000/01 Brierley, Andrew Stuart Goss, C Grant, SA Watkins, JL Reid, K Belchier, M Everson, I Jessop, MJ Afanasyev, V Robst, J 2002 https://risweb.st-andrews.ac.uk/portal/en/researchoutput/significant-intraannual-variability-in-krill-distribution-and-abundance-at-south-georgia-as-revealed-by-multiple-acoustic-surveys-during-200001(a7e24790-418b-4fe8-8afb-80ae96e4ed90).html http://www.scopus.com/inward/record.url?scp=0346108602&partnerID=8YFLogxK eng eng info:eu-repo/semantics/restrictedAccess Brierley , A S , Goss , C , Grant , SA , Watkins , JL , Reid , K , Belchier , M , Everson , I , Jessop , MJ , Afanasyev , V & Robst , J 2002 , ' Significant intra-annual variability in krill distribution and abundance at South Georgia as revealed by multiple acoustic surveys during 2000/01 ' , CCAMLR Science , vol. 9 , pp. 71-82 . acoustic survey variability Antarctic krill abundance South Georgia CCAMLR SEALS ARCTOCEPHALUS-GAZELLA SUB-ANTARCTIC ISLAND EUPHAUSIA-SUPERBA FISH STOCKS STRENGTH SEASON article 2002 ftunstandrewcris 2021-12-26T14:10:56Z Three separate acoustic surveys of Antarctic krill (Euphausia superba) were conducted around South Georgia in the 2000/01 season: in October 2000 (early-season); during late December/early January 2000/01 (mid-season), and in March 2001 (late-season). The surveys were the first in a newly planned five-year series of observations designed to complement and extend an existing time series regularly maintained by the British Antarctic Survey since 1996 (and on a more ad hoc basis since the early 1980s). We hoped that conducting several surveys in one season would provide information on short-term variability that could be used to set data from more restricted once-per-season 'snap-shot' cruises in a broader context. The early- and late-season surveys were associated with logistic support voyages to South Georgia and were restricted to four transects within a box to the northwest of South Georgia. The dedicated mid-season survey covered that box in more detail (twice as many transects) and, in addition, examined boxes to the north, northeast and southwest of the island. Together these surveys provided temporally and spatially extensive coverage around South Georgia. Krill density in the western box in the early-season survey was very low (3.5 g m(-2)) but rose significantly (P = 0.020) by mid-season (to 34.7 g m(-2)). In a pattern that is consistent with observations from previous years, krill density in the western box in the mid-season survey was less than that in the eastern box (80.4 g m(-2)). Analysis of transect data obtained in the western box in the mid-season survey revealed no significant difference in the mean krill density derived from only those four transects surveyed early- and late-season, or from the full eight transects. Our first occupation of a survey box off the central north coast of South Georgia in mid-season revealed a krill density of 47.2 g m(-2) that was intermediate between the eastern and western areas. The size structure of the krill in the central region also reflected a mix of those ... Article in Journal/Newspaper Antarc* Antarctic Antarctic Krill Arctocephalus gazella British Antarctic Survey Euphausia superba University of St Andrews: Research Portal Antarctic
institution Open Polar
collection University of St Andrews: Research Portal
op_collection_id ftunstandrewcris
language English
topic acoustic survey
variability
Antarctic krill
abundance
South Georgia
CCAMLR
SEALS ARCTOCEPHALUS-GAZELLA
SUB-ANTARCTIC ISLAND
EUPHAUSIA-SUPERBA
FISH STOCKS
STRENGTH
SEASON
spellingShingle acoustic survey
variability
Antarctic krill
abundance
South Georgia
CCAMLR
SEALS ARCTOCEPHALUS-GAZELLA
SUB-ANTARCTIC ISLAND
EUPHAUSIA-SUPERBA
FISH STOCKS
STRENGTH
SEASON
Brierley, Andrew Stuart
Goss, C
Grant, SA
Watkins, JL
Reid, K
Belchier, M
Everson, I
Jessop, MJ
Afanasyev, V
Robst, J
Significant intra-annual variability in krill distribution and abundance at South Georgia as revealed by multiple acoustic surveys during 2000/01
topic_facet acoustic survey
variability
Antarctic krill
abundance
South Georgia
CCAMLR
SEALS ARCTOCEPHALUS-GAZELLA
SUB-ANTARCTIC ISLAND
EUPHAUSIA-SUPERBA
FISH STOCKS
STRENGTH
SEASON
description Three separate acoustic surveys of Antarctic krill (Euphausia superba) were conducted around South Georgia in the 2000/01 season: in October 2000 (early-season); during late December/early January 2000/01 (mid-season), and in March 2001 (late-season). The surveys were the first in a newly planned five-year series of observations designed to complement and extend an existing time series regularly maintained by the British Antarctic Survey since 1996 (and on a more ad hoc basis since the early 1980s). We hoped that conducting several surveys in one season would provide information on short-term variability that could be used to set data from more restricted once-per-season 'snap-shot' cruises in a broader context. The early- and late-season surveys were associated with logistic support voyages to South Georgia and were restricted to four transects within a box to the northwest of South Georgia. The dedicated mid-season survey covered that box in more detail (twice as many transects) and, in addition, examined boxes to the north, northeast and southwest of the island. Together these surveys provided temporally and spatially extensive coverage around South Georgia. Krill density in the western box in the early-season survey was very low (3.5 g m(-2)) but rose significantly (P = 0.020) by mid-season (to 34.7 g m(-2)). In a pattern that is consistent with observations from previous years, krill density in the western box in the mid-season survey was less than that in the eastern box (80.4 g m(-2)). Analysis of transect data obtained in the western box in the mid-season survey revealed no significant difference in the mean krill density derived from only those four transects surveyed early- and late-season, or from the full eight transects. Our first occupation of a survey box off the central north coast of South Georgia in mid-season revealed a krill density of 47.2 g m(-2) that was intermediate between the eastern and western areas. The size structure of the krill in the central region also reflected a mix of those ...
format Article in Journal/Newspaper
author Brierley, Andrew Stuart
Goss, C
Grant, SA
Watkins, JL
Reid, K
Belchier, M
Everson, I
Jessop, MJ
Afanasyev, V
Robst, J
author_facet Brierley, Andrew Stuart
Goss, C
Grant, SA
Watkins, JL
Reid, K
Belchier, M
Everson, I
Jessop, MJ
Afanasyev, V
Robst, J
author_sort Brierley, Andrew Stuart
title Significant intra-annual variability in krill distribution and abundance at South Georgia as revealed by multiple acoustic surveys during 2000/01
title_short Significant intra-annual variability in krill distribution and abundance at South Georgia as revealed by multiple acoustic surveys during 2000/01
title_full Significant intra-annual variability in krill distribution and abundance at South Georgia as revealed by multiple acoustic surveys during 2000/01
title_fullStr Significant intra-annual variability in krill distribution and abundance at South Georgia as revealed by multiple acoustic surveys during 2000/01
title_full_unstemmed Significant intra-annual variability in krill distribution and abundance at South Georgia as revealed by multiple acoustic surveys during 2000/01
title_sort significant intra-annual variability in krill distribution and abundance at south georgia as revealed by multiple acoustic surveys during 2000/01
publishDate 2002
url https://risweb.st-andrews.ac.uk/portal/en/researchoutput/significant-intraannual-variability-in-krill-distribution-and-abundance-at-south-georgia-as-revealed-by-multiple-acoustic-surveys-during-200001(a7e24790-418b-4fe8-8afb-80ae96e4ed90).html
http://www.scopus.com/inward/record.url?scp=0346108602&partnerID=8YFLogxK
geographic Antarctic
geographic_facet Antarctic
genre Antarc*
Antarctic
Antarctic Krill
Arctocephalus gazella
British Antarctic Survey
Euphausia superba
genre_facet Antarc*
Antarctic
Antarctic Krill
Arctocephalus gazella
British Antarctic Survey
Euphausia superba
op_source Brierley , A S , Goss , C , Grant , SA , Watkins , JL , Reid , K , Belchier , M , Everson , I , Jessop , MJ , Afanasyev , V & Robst , J 2002 , ' Significant intra-annual variability in krill distribution and abundance at South Georgia as revealed by multiple acoustic surveys during 2000/01 ' , CCAMLR Science , vol. 9 , pp. 71-82 .
op_rights info:eu-repo/semantics/restrictedAccess
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