Interannual changes in the zooplankton community structure on the southeastern Bering Sea shelf during summers of 1994–2009

Abstract

17On the southeastern Bering Sea shelf, mesozooplankton play an important role in 18 material transfer between primary producers and fisheries resources. The biomass of 19 mesozooplankton in this region is known to vary annually, but little is known about 20 annual changes in community structure and species composition. In the present study, 21 regional and long-term changes in abundance, biomass and community structure of

Seasonal decoupling of particulate organic carbon export and net primary production in relation to sea-ice at the shelf break of the eastern Bering Sea: Implications for off-shelf carbon export

“…The observed seasonal shift in associated particle export and e ‐ratio is consistent with the revised OCH, which suggests bottom up control on age‐0 walleye pollock recruitment during cold years [ Hunt et al ., ]. Recent evidence indicates large spring phytoplankton blooms associated with the MIZ of sea‐ice retreat during cold years favor the production of large crustacean zooplankton, such as Calanus marshallae and euphausiids, a common prey of juvenile and adult pollock, while the abundance of smaller copepods is independent of the type of spring bloom [ Hunt et al ., ; Ohashi et al ., ]. Furthermore, in cold years, average energy densities in first year pollock are 33% greater in fall than during warms years, most likely attributed to abundant large zooplankton as a primary diet source [ Heintz et al ., ; Ohashi et al ., ; Siddon et al ., ].…”

Copepod dynamics across warm and cold periods in the eastern Bering Sea: Implications for walleye pollock (Gadus chalcogrammus) and the Oscillating Control Hypothesis

“…Sea ice changes have been linked to shifts in phytoplankton bloom dynamics and total system productivity (Lomas et al., ; Niebauer, Alexander, & Henrichs, , ; Sambroto, Niebauer, Goering, & Iverson, ). Zooplankton populations have also shown differences during warm and cold periods in the Bering Sea (Eisner, Napp, Mier, Pinchuk, & Andrews, ; Ohashi et al., ; Pinchuk, Coyle, Farley, & Renner, ; Volkov, ). Changes in the zooplankton community are relevant because the vast majority of fish species rely on zooplankton as prey during their early life stages when pre‐recruitment mortality is at its highest and year‐class strength is determined (Cushing, , ; Hjort, ; Houde, ).…”

“…There is general consensus that Calanus spp. abundance increases on the middle shelf during cold periods (Baier & Napp, ; Coyle, Pinchuk, Eisner, & Napp, ; Eisner et al., ; Jin, Deal, Wang, & McRoy, ; Ohashi et al., ; Smith & Vidal, ); however, one study did find that Calanus marshallae abundance increased during June at locations along the inner shelf during warm conditions (Coyle & Pinchuk, ). Other copepod taxa ( Acartia spp., Oithona spp., Magnapinna pacifica and Pseudocalanus spp.)…”

Fauna of tintinnids (Tintinnida, Ciliata) during an Arctic-Antarctic cruise, with the S/V “Croatian Tern”

“…The South eastern Bering Sea is a rich biological ecosystem that is one of the world's largest fisheries (Olson & Strom 2002). The importance of mesozooplankton in the ecology of the area was noted by Eisner et al (2013) and Ohashi et al (2013). The abundance of tintinnids in the Chuchi Sea was high but still 93% lower than the values that were recorded in the Bering Sea, with significantly different fauna, with the dominant species being Tintinnopsis beroidea and Helicostomella subulata.…”