2002 ARCSS All-Hands Workshop

Benthic Community Composition and Biomass Distribution: Viral, Bacterial, and Infaunal Associations from the Gulf of Alaska to the Canadian Archipelago

Arianne L. Balsom¹, Jacqueline M. Grebmeier², Lee W. Cooper³, Steven W. Wilhelm^4
1Ecology and Evolutionary Biology, University of Tennessee, 10515 Research Dr, Suite 100, Knoxville, TN, 37996, USA, Phone 865-974-6160, Merrow1@aol.com
²Ecology and Evolutionary Biology, University of Tennessee, 10515 Research Dr, Suite 100, Knoxville, TN, 37996, USA, Phone 865-974-6160, jgrebmei@utk.edu
³Ecology and Evolutionary Biology, University of Tennessee, 10515 Research Dr, Suite 100, Knoxville, TN, 37996, USA, Phone 865-974-6160, lcooper1@utk.edu
⁴Microbiology, University of Tennessee, M409 Walters Life Sciences, Knoxville, TN, 37996, USA, wilhelm@utk.edu

As part of a US-Canada scientific collaboration during the St. Roch II Voyage of Rediscovery in 2000, benthic sediment and water column samples were taken along the continental shelf from the Gulf of Alaska, the Bering, Chukchi and Beaufort Seas, and within the Canadian Archipelago (C.A.) as east as Spence Bay, Nunavut.

Bivalves in the southern stations dominated infaunal biomass. Yoldia sp. in the Gulf of Alaska, Nuculana radiata, Nucula bellot, and M. calcarea in the Bering Strait regions. Ampeliscid amphipods dominated northern Bering Strait stations. Sternaspid polychaetes and ampeliscid amphipods were dominant in the Beaufort Sea samples and entering the C.A. At Hat Island in the C.A., bivalves again dominated, particularly the families Astartidae and Hiatellidae. A siliceous sponge dominated the most northeasterly station, near Spence Bay. Benthic biomass ranged from 57.80 gC/m² in the southern Chukchi Sea to 0.16 gC/m² in the C.A. Infaunal "hot spots" were observed at Hat Island (43.77 gC/m²) and Whale Bluff (21.76 gC/m²) in the C.A., comparable to many of the Bering Strait biomass measurements.

Water column virus-like particles (VLP) ranged from 2.25x10¹¹ L^-1 in the Gulf of Alaska to 5.64x10⁹ L^-1 in the C.A.; bacterial counts ranged from 1.32x10⁹ L^-1 in the Gulf of Alaska to 4.57x10⁷ L^-1 in the C.A. Integrated water column VLP and bacterial distributions correlated most significantly with integrated chlorophyll a; discrete water column VLP and bacterial distribution correlated most significantly with chlorophyll a and temperature, but also with other water column characteristics.

Sediment bacterial counts ranged from 3.18x10⁸ per gram dry weight in the Bering Sea to 1.74x10⁶ per gram dry weight in the C.A. VLP counts ranged from 1.08x10⁹ per gram dry weight in the St Lawrence Island region of the Bering Sea to 2.12x10⁷ in the Archipelago, however at one C.A. station the VLP was observed at 1.22x10⁹ per gram dry weight.

The high VLP and bacterial abundances in sediments associated with water column abundances and high infaunal benthic biomass suggest that biomass accumulation in the sediments may be more influenced by potential sediment microbial reprocessing than previously discussed.

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