Stepping stones towards Antarctica: Switch to southern spawning grounds explains an abrupt range shift in krill
Poleward range shifts are a global-scale response to warming, but these vary greatly among taxa and are hard to predict for individual species, localized regions or over shorter (years to decadal) timescales. Moving poleward might be easier in the Arctic than in the Southern Ocean, where evidence fo...
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ftwilliammarycol:oai:scholarworks.wm.edu:vimsarticles-3241 2023-06-11T04:07:01+02:00 Stepping stones towards Antarctica: Switch to southern spawning grounds explains an abrupt range shift in krill Atkinson, Angus Hill, Simeon L. (.) Steinberg, Deborah K. 2022-01-01T08:00:00Z application/pdf https://scholarworks.wm.edu/vimsarticles/2240 https://doi.org/10.1111/gcb.16009 https://scholarworks.wm.edu/context/vimsarticles/article/3241/viewcontent/Global_Change_Biology___2021___Atkinson.pdf unknown W&M ScholarWorks https://scholarworks.wm.edu/vimsarticles/2240 doi: DOI:10.1111/gcb.16009 https://scholarworks.wm.edu/context/vimsarticles/article/3241/viewcontent/Global_Change_Biology___2021___Atkinson.pdf http://creativecommons.org/licenses/by/4.0/ VIMS Articles abrupt community shift Antarctic krill ecosystem shift euphausiid management marine protected areas range shift recruitment spawning Biological Sciences Peer-Reviewed Articles Marine Biology text 2022 ftwilliammarycol https://doi.org/10.1111/gcb.16009</p>10.1111/gcb.16009 2023-05-04T17:50:52Z Poleward range shifts are a global-scale response to warming, but these vary greatly among taxa and are hard to predict for individual species, localized regions or over shorter (years to decadal) timescales. Moving poleward might be easier in the Arctic than in the Southern Ocean, where evidence for range shifts is sparse and contradictory. Here, we compiled a database of larval Antarctic krill, Euphausia superba and, together with an adult database, it showed how their range shift is out of step with the pace of warming. During a 70-year period of rapid warming (1920s–1990s), distribution centres of both larvae and adults in the SW Atlantic sector remained fixed, despite warming by 0.5–1.0°C and losing sea ice. This was followed by a hiatus in surface warming and ice loss, yet during this period the distributions of krill life stages shifted greatly, by ~1000 km, to the south-west. Understanding the mechanism of such step changes is essential, since they herald system reorganizations that are hard to predict with current modelling approaches. We propose that the abrupt shift was driven by climatic controls acting on localized recruitment hotspots, superimposed on thermal niche conservatism. During the warming hiatus, the Southern Annular Mode index continued to become increasingly positive and, likely through reduced feeding success for larvae, this led to a precipitous decline in recruitment from the main reproduction hotspot along the southern Scotia Arc. This cut replenishment to the northern portion of the krill stock, as evidenced by declining density and swarm frequency. Concomitantly, a new, southern reproduction area developed after the 1990s, reinforcing the range shift despite the lack of surface warming. New spawning hotspots may provide the stepping stones needed for range shifts into polar regions, so planning of climate-ready marine protected areas should include these key areas of future habitat. Text Antarc* Antarctic Antarctic Krill Antarctica Arctic Euphausia superba Sea ice Southern Ocean Stepping Stones W&M ScholarWorks Antarctic Arctic Southern Ocean Stepping Stones ENVELOPE(-63.992,-63.992,-64.786,-64.786) |
institution |
Open Polar |
collection |
W&M ScholarWorks |
op_collection_id |
ftwilliammarycol |
language |
unknown |
topic |
abrupt community shift Antarctic krill ecosystem shift euphausiid management marine protected areas range shift recruitment spawning Biological Sciences Peer-Reviewed Articles Marine Biology |
spellingShingle |
abrupt community shift Antarctic krill ecosystem shift euphausiid management marine protected areas range shift recruitment spawning Biological Sciences Peer-Reviewed Articles Marine Biology Atkinson, Angus Hill, Simeon L. (.) Steinberg, Deborah K. Stepping stones towards Antarctica: Switch to southern spawning grounds explains an abrupt range shift in krill |
topic_facet |
abrupt community shift Antarctic krill ecosystem shift euphausiid management marine protected areas range shift recruitment spawning Biological Sciences Peer-Reviewed Articles Marine Biology |
description |
Poleward range shifts are a global-scale response to warming, but these vary greatly among taxa and are hard to predict for individual species, localized regions or over shorter (years to decadal) timescales. Moving poleward might be easier in the Arctic than in the Southern Ocean, where evidence for range shifts is sparse and contradictory. Here, we compiled a database of larval Antarctic krill, Euphausia superba and, together with an adult database, it showed how their range shift is out of step with the pace of warming. During a 70-year period of rapid warming (1920s–1990s), distribution centres of both larvae and adults in the SW Atlantic sector remained fixed, despite warming by 0.5–1.0°C and losing sea ice. This was followed by a hiatus in surface warming and ice loss, yet during this period the distributions of krill life stages shifted greatly, by ~1000 km, to the south-west. Understanding the mechanism of such step changes is essential, since they herald system reorganizations that are hard to predict with current modelling approaches. We propose that the abrupt shift was driven by climatic controls acting on localized recruitment hotspots, superimposed on thermal niche conservatism. During the warming hiatus, the Southern Annular Mode index continued to become increasingly positive and, likely through reduced feeding success for larvae, this led to a precipitous decline in recruitment from the main reproduction hotspot along the southern Scotia Arc. This cut replenishment to the northern portion of the krill stock, as evidenced by declining density and swarm frequency. Concomitantly, a new, southern reproduction area developed after the 1990s, reinforcing the range shift despite the lack of surface warming. New spawning hotspots may provide the stepping stones needed for range shifts into polar regions, so planning of climate-ready marine protected areas should include these key areas of future habitat. |
format |
Text |
author |
Atkinson, Angus Hill, Simeon L. (.) Steinberg, Deborah K. |
author_facet |
Atkinson, Angus Hill, Simeon L. (.) Steinberg, Deborah K. |
author_sort |
Atkinson, Angus |
title |
Stepping stones towards Antarctica: Switch to southern spawning grounds explains an abrupt range shift in krill |
title_short |
Stepping stones towards Antarctica: Switch to southern spawning grounds explains an abrupt range shift in krill |
title_full |
Stepping stones towards Antarctica: Switch to southern spawning grounds explains an abrupt range shift in krill |
title_fullStr |
Stepping stones towards Antarctica: Switch to southern spawning grounds explains an abrupt range shift in krill |
title_full_unstemmed |
Stepping stones towards Antarctica: Switch to southern spawning grounds explains an abrupt range shift in krill |
title_sort |
stepping stones towards antarctica: switch to southern spawning grounds explains an abrupt range shift in krill |
publisher |
W&M ScholarWorks |
publishDate |
2022 |
url |
https://scholarworks.wm.edu/vimsarticles/2240 https://doi.org/10.1111/gcb.16009 https://scholarworks.wm.edu/context/vimsarticles/article/3241/viewcontent/Global_Change_Biology___2021___Atkinson.pdf |
long_lat |
ENVELOPE(-63.992,-63.992,-64.786,-64.786) |
geographic |
Antarctic Arctic Southern Ocean Stepping Stones |
geographic_facet |
Antarctic Arctic Southern Ocean Stepping Stones |
genre |
Antarc* Antarctic Antarctic Krill Antarctica Arctic Euphausia superba Sea ice Southern Ocean Stepping Stones |
genre_facet |
Antarc* Antarctic Antarctic Krill Antarctica Arctic Euphausia superba Sea ice Southern Ocean Stepping Stones |
op_source |
VIMS Articles |
op_relation |
https://scholarworks.wm.edu/vimsarticles/2240 doi: DOI:10.1111/gcb.16009 https://scholarworks.wm.edu/context/vimsarticles/article/3241/viewcontent/Global_Change_Biology___2021___Atkinson.pdf |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1111/gcb.16009</p>10.1111/gcb.16009 |
_version_ |
1768379441866604544 |