Pelagic-benthic coupling on the shelf of the northern Bering and Chukchi Seas. I. Food supply source and benthic bio-mass

Abstract

The shelf waters of the northern Bering and Chukchi Seas are ice-covered for 7 mo of the year, but despite thls harsh environment, they are characterized by high benthic biomass. Coupling between water column primary production and the benthos was investigated in summers 1984 to 1986 by measurements of sediment characteristics in relation to those of the water column. Low surface sediment C/N ratios (5.8 to 7.6) suggested a higher quality, nitrogen-rich marine carbon supply to the benthos in the highly productive (ca 250 to 300 g C m-' yr-') Bering Shelf-Anadyr Water (BSAW) compared to lower quality, higher C/N ratios (7 7 to 14 0) in sediment under the less productive (ca 50 g C m-' yr-l) Alaska Coastal Water (ACW). Stable carbon isotope ratios suggested a manne origin for organic matter in BSAW compared to a mixture of manne and terrestrial input in ACW. Mean benthic biomass was significantly different between water locations, with mean benthic biomass decreasing from 20.2 g C m-* under BSAW to 6.3 g C m-2 under ACW Summer benthic biomass remained seasonally constant for the 3 yr. Benthic communities underlying BSAW received a high quality marine food supply on a regular basis interannually, while those in ACW received an interannually variable amount of temgenous organic matter in addition to marine organic matter. We conclude that the quality and quantity of organic carbon deposited to the benthos directly influence benthic biomass.

Remote sensing of size structure of phytoplankton communities using optical properties of the Chukchi and Bering Sea shelf region

“…BSW flows between AW and ACW. Its water density is very similar to that of AW, so they become well mixed when they pass through the Bering Strait (Grebmeier et al, 1988). This mixed water, called Bering Shelf-Anadyr Water (BSAW) (Grebmeier et al, 1988) supplies nutrient-rich water to the southern Chukchi Sea.…”

Algal pigments in Southern Ocean abyssal foraminiferans indicate pelagobenthic coupling

“…Many factors affect the sinking particles and the largest part of the phytoplankton production is re-mineralized on its way down to the abyssal depths (Dayton et al, 1994;Grebmeier et al, 1988). It is estimated that only 0.01-1% remain after passage through the water column (Gooday, 2003).…”

“…The quality and quantity of this input, the pelago-benthic coupling, will determine the structure and function of the communities (Dayton et al, 1994;Epping, 2013;Fabiano et al, 1997;Gooday, 2002;Graf, 1989;Graf et al, 1995;Grebmeier et al, 1988;Grebmeier and Barry, 1991;Hughes et al, 2007;Schnack-Schiel and Isla, 2005;Smith et al, 2006Smith et al, , 2013. This input occurs as sinking of particles produced at the surface (Asper et al, 1992;Fabiano et al, 1997).…”

The Barents and Chukchi Seas: Comparison of two Arctic shelf ecosystems

“…In shallow water, there is less opportunity for material to be consumed by zooplankton before it reaches the bottom (Grebmeier et al, 1988(Grebmeier et al, , 2006a, and there is less opportunity for material to decompose as it sinks. Secondly, in shallow water, such as at Hannah and Harold shoals in the Chukchi Sea, phytoplankton becomes directly available for benthos, especially filter feeders.…”