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Recent Trends in Eastern Bering Sea Zooplankton: Data and Confessions. J.M. Napp 1 , P.J. Stabeno 2 , D.V. Holliday 3 and G.L. Hunt, Jr. 4. 1 NOAA – Fisheries, Alaska Fisheries Science Center 2 NOAA – Research, Pacific Marine Environmental Laboratory
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Recent Trends in Eastern Bering Sea Zooplankton: Data and Confessions J.M. Napp1, P.J. Stabeno2, D.V. Holliday3 and G.L. Hunt, Jr.4 1NOAA – Fisheries, Alaska Fisheries Science Center 2NOAA – Research, Pacific Marine Environmental Laboratory 3University of Massachusetts, Dartmouth, School for Marine Science and Technology, and University of Rhode Island, Graduate School of Oceanography 4School of Aquatic and Fishery Sciences, University of Washington
Value of Zooplankton Times Series • Establishes “baseline” conditions. • Demonstrates lower trophic level responses to perturbations. • Provides insight and understanding into natural cycles or stochastic environmental forcing. • Provides insight and connectivity to fisheries recruitment and the productivity of upper trophic levels.
Time Series of the Northeast Pacific, Warm / Less Productive Cool / Most Productive Mackas, Batten, and Trudel (2007) Prog. Oceanogr.
Eastern Bering Sea, T/S Oshoro maru Napp and Yamaguchi, unpubl.
AFSC – RACE Groundfish Survey Zooplankton Sampling 2006, Leg 2 2008, Legs 1, 2 & 3 2007, Legs 1 & 2
Recent Trends in C. marshallae Coyle et al. “Zooplankton species composition on the southeastern Bering Sea shelf during summer…”
Spatial Variability in T/S Oshoro maru Sampling 1966 1998 1993 Napp et al., (2002) Deep-Sea Res., II
Temporal Aliasing in Sampling Biomass (mg m-3) Date
Acoustically-Determined Zooplankton Biomass @ M2 2006 2006 Biovolume (mm3 m-3) 2007 2007
Conclusions BEST-BSIERP Ecosystem Partnership • Total zooplankton biomass appears to be “recovering” from the recent warm period. • The abundance of Calanus marshallae over the middle shelf is an important contributor to that biomass, and it is also increasing. • Present time series need to be strengthened, expanded and further tested for potential aliasing. • Retrospective analysis of T/S Oshoro maru species data. • Comparability among shipboard acoustics, moored acoustics, net samples. • Eastern Bering Sea zooplankton data are an excellent candidate metric for an aggregate index to explain ecosystem productivity. http://bsierp.nprb.org
Acknowledgements BEST-BSIERP Ecosystem Partnership • Funding from NPRB (regular and BSIERP) and NOAA’s NPCREP Programs. • Mooring group at PMEL. • AFSC RACE Bering Sea Groundfish Assessment Group. http://bsierp.nprb.org
Time Series of the Northeast Pacific, II Mackas, Batten, and Trudel (2007) Prog. Oceanogr.
134 C. marshallae m-3 33 C. marshallae m-3 51 C. marshallae m-3