TY - JOUR
T1 - Long-term (1993-2013) changes in macrozooplankton off the western antarctic peninsula
AU - Steinberg, Deborah K.
AU - Ruck, Kate E.
AU - Gleiber, Miram R.
AU - Garzio, Lori M.
AU - Cope, Joseph S.
AU - Bernard, Kim S.
AU - Stammerjohn, Sharon E.
AU - Schofield, Oscar M.E.
AU - Quetin, Langdon B.
AU - Ross, Robin M.
N1 - Funding Information:
We thank the Captain, officers, and crew of the MV Polar Duke and ARSV Laurence M. Gould , and Raytheon Polar Services and Lockheed Martin personnel for their scientific and logistical support. We are grateful to the many student volunteers that assisted during the PAL LTER cruises and in the laboratory. We thank Doug Martinson and Rich Iannuzzi for consult on sea surface temperature data, Grace Saba for advice with climate index analyses, Josh Stone for assistance with figure preparation, and Hugh Ducklow for helpful discussions and his leadership of the PAL LTER. We also thank B. Prezelin, M. Vernet and R. Smith for historical PP and Chl a data used in our analyses. This research was supported by the National Science Foundation Antarctic Organisms and Ecosystems Program ( OPP-0823101 ). This is contribution number 3450 from the Virginia Institute of Marine Science.
Publisher Copyright:
© 2015 Elsevier Ltd.
PY - 2015/7/1
Y1 - 2015/7/1
N2 - The Western Antarctic Peninsula (WAP) is one of the most rapidly warming regions on Earth, and where a high apex predator biomass is supported in large part by macrozooplankton. We examined trends in summer (January-February) abundance of major taxa of macrozooplankton along the WAP over two decades (1993-2013) and their relationship with environmental parameters (sea ice, atmospheric climate indices, sea surface temperature, and phytoplankton biomass and productivity). Macrozooplankton were collected from the top 120. m of the water column in a mid-Peninsula study region divided into latitudinal (North, South, and Far South) and cross-shelf (coastal, shelf, slope) sub-regions. Trends for krill species included a 5-year cycle in abundance peaks (positive anomalies) for Euphausia superba, but no directional long-term trend, and an increase in Thysanoessa macrura in the North; variability in both species was strongly influenced by primary production 2-years prior. E. crystallorophias abundance was best explained by the Southern Annular Mode (SAM) and Multivariate El Niño Southern Oscillation Index (MEI), and was more abundant in higher ice conditions. The salp Salpa thompsoni and thecosome pteropod Limacina helicina cycled between negative and positive anomalies in the North, but showed increasing positive anomalies in the South over time. Variation in salp and pteropod abundance was best explained by SAM and the MEI, respectively, and both species were more abundant in lower ice conditions. There was a long-term increase in some carnivorous gelatinous zooplankton (polychaete worm Tomopteris spp.) and amphipods. Abundance of Pseudosagitta spp. chaetognaths was closely related to SAM, with higher abundance tied to lower ice conditions. Long-term changes and sub-decadal cycles of WAP macrozooplankton community composition may affect energy transfer to higher trophic levels, and alter biogeochemical cycling in this seasonally productive and sensitive polar ecosystem.
AB - The Western Antarctic Peninsula (WAP) is one of the most rapidly warming regions on Earth, and where a high apex predator biomass is supported in large part by macrozooplankton. We examined trends in summer (January-February) abundance of major taxa of macrozooplankton along the WAP over two decades (1993-2013) and their relationship with environmental parameters (sea ice, atmospheric climate indices, sea surface temperature, and phytoplankton biomass and productivity). Macrozooplankton were collected from the top 120. m of the water column in a mid-Peninsula study region divided into latitudinal (North, South, and Far South) and cross-shelf (coastal, shelf, slope) sub-regions. Trends for krill species included a 5-year cycle in abundance peaks (positive anomalies) for Euphausia superba, but no directional long-term trend, and an increase in Thysanoessa macrura in the North; variability in both species was strongly influenced by primary production 2-years prior. E. crystallorophias abundance was best explained by the Southern Annular Mode (SAM) and Multivariate El Niño Southern Oscillation Index (MEI), and was more abundant in higher ice conditions. The salp Salpa thompsoni and thecosome pteropod Limacina helicina cycled between negative and positive anomalies in the North, but showed increasing positive anomalies in the South over time. Variation in salp and pteropod abundance was best explained by SAM and the MEI, respectively, and both species were more abundant in lower ice conditions. There was a long-term increase in some carnivorous gelatinous zooplankton (polychaete worm Tomopteris spp.) and amphipods. Abundance of Pseudosagitta spp. chaetognaths was closely related to SAM, with higher abundance tied to lower ice conditions. Long-term changes and sub-decadal cycles of WAP macrozooplankton community composition may affect energy transfer to higher trophic levels, and alter biogeochemical cycling in this seasonally productive and sensitive polar ecosystem.
KW - Climate
KW - Krill
KW - Sea ice
KW - Southern ocean
KW - Zooplankton
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UR - http://www.scopus.com/inward/citedby.url?scp=84926685633&partnerID=8YFLogxK
U2 - 10.1016/j.dsr.2015.02.009
DO - 10.1016/j.dsr.2015.02.009
M3 - Article
AN - SCOPUS:84926685633
SN - 0967-0637
VL - 101
SP - 54
EP - 70
JO - Deep-Sea Research Part I: Oceanographic Research Papers
JF - Deep-Sea Research Part I: Oceanographic Research Papers
ER -