Oceanography of the eastern Bering Sea ice‐edge zone in spring1

Alexander, Vera; Niebauer, H. J.

doi:10.4319/lo.1981.26.6.1111

Cited by 183 publications

(85 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Unfortunately, the salinity stratification is difficult to infer using satellite or reanalysis data. However, Alexander and Niebauer (1981) showed that the development of both salinity and thermal stratification induces water column stability, which generally triggers the ice-edge phytoplankton bloom in the Bering Sea. Thus, OHC was used as a proxy of the development of the surface mixed layer.…”

Section: Influence Of Tsr On Phytoplankton Size Composition During MImentioning

confidence: 99%

Influence of timing of sea ice retreat on phytoplankton size during marginal ice zone bloom period on the Chukchi and Bering shelves

et al. 2016

View full text Add to dashboard Cite

Abstract. The size structure and biomass of a phytoplankton community during the spring bloom period can affect the energy use of higher-trophic-level organisms through the predator-prey body size relationships. The timing of the sea ice retreat (TSR) also plays a crucial role in the seasonally ice-covered marine ecosystem, because it is tightly coupled with the timing of the spring bloom. Thus, it is important to monitor the temporal and spatial distributions of a phytoplankton community size structure. Prior to this study, an ocean colour algorithm was developed to derive phytoplankton size index F L , which is defined as the ratio of chlorophyll a (chl a) derived from cells larger than 5 µm to the total chl a, using satellite remote sensing for the Chukchi and Bering shelves. Using this method, we analysed the pixel-bypixel relationships between F L during the marginal ice zone (MIZ) bloom period and TSR over the period of 1998-2013. The influences of the TSR on the sea surface temperature (SST) and changes in ocean heat content ( OHC) during the MIZ bloom period were also investigated. A significant negative relationship between F L and the TSR was widely found in the shelf region during the MIZ bloom season. However, we found a significant positive (negative) relationship between the SST ( OHC) and TSR. Specifically, an earlier sea ice retreat was associated with the dominance of larger phytoplankton during a colder and weakly stratified MIZ bloom season, suggesting that the duration of the nitrate supply, which is important for the growth of large-sized phytoplankton in this region (i.e. diatoms), can change according to the TSR. In addition, under-ice phytoplankton blooms are likely to occur in years with late ice retreat, because sufficient light for phytoplankton growth can pass through the ice and penetrate into the water columns as a result of an increase in solar radiation toward the summer solstice. Moreover, we found that both the length of the ice-free season and the annual median of F L positively correlated with the annual net primary production (APP). Thus, both the phytoplankton community composition and growing season are important for the APP in the study area. Our findings showed a quantitative relationship between the interannual variability of F L , the TSR, and the APP, which suggested that satellite remote sensing of the phytoplankton community size structure is suitable to document the impact of a recent rapid sea ice loss on the ecosystem of the study region.

show abstract

Section: Influence Of Tsr On Phytoplankton Size Composition During MImentioning

confidence: 99%

Influence of timing of sea ice retreat on phytoplankton size during marginal ice zone bloom period on the Chukchi and Bering shelves

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Ice remains there longer there than in the southeastern Bering Sea, and shows less interannual variation . Thus, it might be expected that most phytoplankton production there would be associated with the melting of the sea ice and would occur in cold water as described by Alexander and Niebauer (1981) and Niebauer, Alexander & Henrichs, 1990, 1995. These conditions might be expected to result in slower growth and a lesser production of zooplankton, and thus a bottom-up limitation of fish recruitment compared to farther south on the shelf.…”

Section: The Oscillating Control Hypothesismentioning

confidence: 99%

“…Studies of springtime primary production in the mid1970s emphasized the importance of ice-associated blooms that occurred in cold water (-1°C) (e.g. Alexander & Niebauer, 1981;Niebauer, Alexander & Henrichs, 1990), whereas those working in the late 1970s and early 1980s emphasized the importance of open water blooms that occurred in comparably warm water (2°-5°C) (e.g. Sambroto et al, 1986;Walsh & McRoy, 1986).…”

Section: Biological Responses To Changes In the Marine Climatementioning

confidence: 99%

Climate change and the control of energy flow in the southeastern Bering Sea

Hunt

Stabeno

2002

Progress in Oceanography

144

View full text Add to dashboard Cite

We examine how coupling between physical and biological processes influences the production and transfer of energy to upper trophic-level species in the southeastern Bering Sea. We review time series that illustrate changes in the marine climate of the southeastern Bering Sea since the mid-1970s, particularly variability in the persistence of sea ice and the timing of its retreat. Time series (1995 -2001) from a biophysical mooring in the middle domain of the southeastern shelf support the hypothesis that retreat of the winter sea ice before mid-March (or the failure of ice to be advected into a region) results in an open water bloom in May or June in relatively warm water (Ն3°C). Conversely, when ice retreat is delayed until mid-March or later, an ice-associated bloom occurs in cold (Յ0°C) water in early spring. These variations are important because the growth and production of zooplankton and the growth and survival of larval and juvenile fish are sensitive to water temperature. The Oscillating Control Hypothesis (OCH) recently proposed by Hunt et al. (2002), predicts that control of the abundance of forage fish, and in the case of walleye pollock (Theragra chalcogramma), recruitment of large piscivorous fish, will switch from bottom-up limitation in extended periods with late ice retreat to top-down in warmer periods when ice retreat occurs before mid-March. In support of this hypothesis, we review recent data from the southeastern Bering Sea that show 2-to 13-fold changes in copepod abundance with changes in spring water temperatures of 3 to 5°C. We also provide indirect evidence that the abundance of adult pollock on the eastern Bering Sea shelf negatively affects the abundance forage fishes (including juvenile pollock) available to top predators. Although there is evidence that pollock year-class strength is positively related to temperature, we lack the time series of pollock populations in extended periods (8 -10 years) of cold-water blooms necessary to test the OCH. 

show abstract

“…These interactions, which include water-column stratification from sea-ice melt (Alexander and Niebauer, 1981), eddies, and wind-driven vertical mixing of nutrients into surface waters, provide the components necessary for high primary productivity.…”

Section: Introductionmentioning

confidence: 99%

Phytoplankton growth, microzooplankton herbivory and community structure in the southeast Bering Sea: insight into the formation and temporal persistence of an Emiliania huxleyi bloom

Olson

Strom

2002

Deep Sea Research Part II: Topical Studies in Oceanography

143

108

View full text Add to dashboard Cite

Using the seawater dilution technique, we measured phytoplankton growth and microzooplankton grazing rates within and outside of the 1999 Bering Sea coccolithophorid bloom. We found that reduced microzooplankton grazing mortality is a key component in the formation and temporal persistence of the Emiliania huxleyi bloom that continues to proliferate in the southeast Bering Sea. Total chlorophyll a (Chl a) at the study sites ranged from 0.40 to 4.45 mg C l À1 . Highest phytoplankton biomass was found within the bloom, which was a mixed assemblage of diatoms and E. huxleyi. Here, 75% of the Chl a came from cells >10 mm and was attributed primarily to the high abundance of the diatom Nitzschia spp. Nutrient-enhanced total phytoplankton growth rates averaged 0.53 d À1 across all experimental stations. Average growth rates for >10 mm and o10 mm cells were nearly equal, while microzooplankton grazing varied among stations and size fractions. Grazing on phytoplankton cells >10 mm ranged from 0.19 to 1.14 d À1 . Grazing on cells o10 mm ranged from 0.02 to 1.07 d À1 , and was significantly higher at non-bloom (avg. 0.71 d À1 ) than at bloom (avg. 0.14 d À1 ) stations. Averaged across all stations, grazing by microzooplankton accounted for 110% and 81% of phytoplankton growth for >10 and o10 mm cells, respectively. These findings contradict the paradigm that microzooplankton are constrained to diets of nanophytoplankton and strongly suggests that their grazing capability extends beyond boundaries assumed by size-based models. Dinoflagellates and oligotrich ciliates dominated the microzooplankton community. Estimates of abundance and biomass for microzooplankton >10 mm were higher than previously reported for the region, ranging from 22,000 to 227,430 cells l À1 and 18 to 164 mg C l À1 . Highest abundance and biomass occurred in the bloom and corresponded with increased abundance of the large ciliate Laboea, and the heterotrophic dinoflagellates Protoperidinium and Gyrodinium spp. Despite low grazing rates on phytoplankton o10 mm within the bloom, the abundance and biomass of small microzooplankton (o20 mm) capable of grazing E. huxleyi was relatively high at bloom stations. This body of evidence, coupled with observed high grazing rates on large phytoplankton cells, suggests the phytoplankton community composition was strongly regulated by herbivorous activity of microzooplankton. Because grazing behavior deviated from size-based model predictions and was not proportional to microzooplankton biomass, alternate mechanisms that dictate levels of grazing activity were in effect in the southeastern Bering Sea. We hypothesize that these mechanisms included morphological or chemical signaling between phytoplankton and micrograzers, which led to selective grazing pressure. r

show abstract

Oceanography of the eastern Bering Sea ice‐edge zone in spring1

Cited by 183 publications

References 10 publications

Influence of timing of sea ice retreat on phytoplankton size during marginal ice zone bloom period on the Chukchi and Bering shelves

Influence of timing of sea ice retreat on phytoplankton size during marginal ice zone bloom period on the Chukchi and Bering shelves

Climate change and the control of energy flow in the southeastern Bering Sea

Phytoplankton growth, microzooplankton herbivory and community structure in the southeast Bering Sea: insight into the formation and temporal persistence of an Emiliania huxleyi bloom

Contact Info

Product

Resources

About