The Impact of Changing Sea Ice and Hydrographic Conditions on Biological Communities in the Northern Bering and Chukchi Seas

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The Impact of Changing Sea Ice and Hydrographic Conditions on Biological Communities in the Northern Bering and Chukchi Seas Jacqueline M. Grebmeier 1, Lee W. Cooper 1, and Karen E.

1 The Impact of Changing Sea Ice and Hydrographic Conditions on Biological Communities in the Northern Bering and Chukchi Seas Jacqueline M. Grebmeier 1, Lee W. Cooper 1, and Karen E. Frey 2 1 University of Maryland Center for Environmental Science Chesapeake Biological Laboratory, Solomons, Maryland USA 2 Graduate School of Geography, Clark University, Massachusetts USA Ecosystem Studies of Sub-Arctic Seas (ESSAS) Open Science Meeting (OSM) May 24, 2011, 1100 Marriott Hotel Seattle, Washington, USA

and retreat and increased ocean temperatures and

indicate these changes are driving shifts in

that may signal ecosystem reorganization

composition and range extensions of benthic

2 INTRODUCTION Arctic Pacific sector is experiencing changes in seasonal sea ice extent and retreat and increased ocean temperatures and freshwater content Emerging observations indicate these changes are driving shifts in marine species composition and carbon cycling that may signal ecosystem reorganization Biological observations include changing composition and range extensions of benthic fauna as prey coincident with more northern migration of marine mammals into Pacific Arctic

3 Sea ice extent (2009) and surface sea water temperatures ( ) in Pacific region Minimum ice extent rd lowest sea ice extent on record

4 Seasonal water mass structure in the Pacific sector C3O Seawater Temperature Slice in July 2008 NORTH PACIFIC ARCTIC [Tom Weingartner and Seth Danielson] [Eddy Carmack/IOS]

5 Earlier spring sea ice retreat, later fall ice formation ~ 2000s vs. 1980s and 1990s 2000s vs. 1980s and 1990s

6 South to north pelagic to benthic ecosystem transition in the Bering Sea Scenario 1. Open Water Blooms D Z F south Scenario 2. Marginal Ice Edge Blooms D Z F north February March April May June Key - Diatoms, Zooplankton, Flagellates [Graphic courtesy of Brad Moran and Mike Lomas-BEST program]

Arctic, Subarctic and Bering Sea: dominant copepods All sketches

Copepods Arctic Ocean Canada Basin Calanus hyperboreus C.

7 Arctic, Subarctic and Bering Sea: dominant copepods All sketches drawn at same magnification; all scale bars represent 1mm Arctic Copepods Arctic Ocean Canada Basin Calanus hyperboreus C. glacialis Metridia longa Chukchi Sea Beaufort Sea Shelf Copepods Pseudocalanus sp. Oithona sp. Russia Bering Sea Copepods Alaska Bering Sea Basin Neocalanus cristatus N. flemingeri Calanus marshallae [courtesy Sharon Smith]

8 Decadal sediment community oxygen consumption indicate spatial patterns of organic carbon deposition to the sediments [Grebmeier in prep. ARMS 2011]

9 Decadal distribution of Total Organic Carbon content as indicator current speed and deposition zones higher TOC associated with silt & clay content, indicative of sediment deposition zones, slower currents [Grebmeier in prep. AMS 2011]

10 Rich benthic communities on the western side of the Bering/Chukchi Sea system [Grebmeier in prep. ARMS 2011]

11 Dominant infaunal taxa includes bivalves, amphipods, polychaetes and sipunculids [Grebmeier in prep. ARMS 2011]

Distributed Biological Observatory (DBO) Sites Regional hotspot loca8ons along a la8tudinal gradient will comprise the DBO sites DBO 6: Barrow Canyon DBO 5: NE Chukchi Sea DBO 4: SE Chukchi Sea DBO

12 Distributed Biological Observatory (DBO) Sites Regional hotspot loca8ons along a la8tudinal gradient will comprise the DBO sites DBO 6: Barrow Canyon DBO 5: NE Chukchi Sea DBO 4: SE Chukchi Sea DBO 3: Bering Strait DBO 2: Chirikov Basin DBO 1: N Bering Sea [modified from Grebmeier et al. 2010, EOS] DBO sites are considered to exhibit high produc8vity, biodiversity, and overall rates of change DBO sites will serve as a change detec8on array for the iden8fica8on and consistent monitoring of biophysical responses

Shifts in sea ice persistence and Chl-a concentration from 2003-2009 6 1 2 4 Based on SSM/I Sea

13 Shifts in sea ice persistence and Chl-a concentration from Based on SSM/I Sea Ice Concentra1ons and the GlobColour (SeaWiFS, MODIS, MERIS) satellite 1me series, courtesy Karen Frey

Threatened spectacled eiders keyed to sea ice and

bivalves shallow shelf system, high cascade

acidification potential dissolve bivalve shells

benthic infauna by exclusion of benthic fish and

14 Threatened spectacled eiders keyed to sea ice and specific bivalves (DBO1) feed on 3 species of bivalves shallow shelf system, high cascade potential lower to higher trophic levels ocean acidification potential dissolve bivalve shells extent & duration cold pool (<0 C) critical to benthic infauna by exclusion of benthic fish and epibenthic predators [Andrew Trites] [Grebmeier et al. 2006, Science 311]

Decline in sediment community oxygen consumption indicative of reduced carbon supply to the benthos SW St. Lawrence Island 45.

15 Decline in sediment community oxygen consumption indicative of reduced carbon supply to the benthos SW St. Lawrence Island Sediment Community Oxygen Consumption (SCOC) (mm O 2 m -2 d -1 ) SCOC (mmol O 2 /m 2/ d) Year winter spring summer fall [update from Grebmeier et al. Science 2006]

Interannual changes in the zooplankton community structure on the southeastern Bering Sea shelf and Chukchi Sea during summers of

Interannual changes in the zooplankton community structure on the southeastern Bering Sea shelf and Chukchi Sea during summers of 1991 29 22 27 Shiberia Chukchi Sea Alaska Pacific Summer Water Bering Sea