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Cold Regime interannual variability of primary and secondary producer community composition in the southeastern Bering Sea.

Stauffer BA, Miksis-Olds J, Goes JI - PLoS ONE (2015)

Bottom Line: Hydrographic conditions in 2012 were significantly different than in 2009, 2010, and 2011, driven largely by increased ice extent and thickness, later ice retreat, and earlier stratification of the water column.There was a high degree of variability in the relationships between different classes of secondary producers and hydrographic conditions, evidence of significant intra-consumer interactions, and trade-offs between different consumer size classes in each year.Overall, primary producers and secondary producers were more tightly coupled to each other and to hydrographic conditions in the coldest year compared to the warmer years.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology and Paleo Environment, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, 10964, United States of America.

ABSTRACT
Variability of hydrographic conditions and primary and secondary productivity between cold and warm climatic regimes in the Bering Sea has been the subject of much study in recent years, while interannual variability within a single regime and across multiple trophic levels has been less well-documented. Measurements from an instrumented mooring on the southeastern shelf of the Bering Sea were analyzed for the spring-to-summer transitions within the cold regime years of 2009-2012 to investigate the interannual variability of hydrographic conditions, primary producer biomass, and acoustically-derived secondary producer and consumer abundance and community structure. Hydrographic conditions in 2012 were significantly different than in 2009, 2010, and 2011, driven largely by increased ice extent and thickness, later ice retreat, and earlier stratification of the water column. Primary producer biomass was more tightly coupled to hydrographic conditions in 2012 than in 2009 or 2011, and shallow and mid-column phytoplankton blooms tended to occur independent of one another. There was a high degree of variability in the relationships between different classes of secondary producers and hydrographic conditions, evidence of significant intra-consumer interactions, and trade-offs between different consumer size classes in each year. Phytoplankton blooms stimulated different populations of secondary producers in each year, and summer consumer populations appeared to determine dominant populations in the subsequent spring. Overall, primary producers and secondary producers were more tightly coupled to each other and to hydrographic conditions in the coldest year compared to the warmer years. The highly variable nature of the interactions between the atmospherically-driven hydrographic environment, primary and secondary producers, and within food webs underscores the need to revisit how climatic regimes within the Bering Sea are defined and predicted to function given changing climate scenarios.

No MeSH data available.


Related in: MedlinePlus

M2 data from March through August 2011.(a) ice extent (%, black boxes) and thickness (blue triangles); (b) shallow (dark blue) and deep (cyan) temperature (° C); (c) shallow (red) and deep (magenta) salinity; (d) stratification (Δσ); (e) shallow (light green) and mid-column (dark green) Chl a fluorescence (μg L-1); (f) total scattering volume (Sv); (g) percent composition of classes of scatterers, including SmCrust (black), MdCrust (blue), LgCrust (red), WkReson (green), StReson (cyan), and Unclass (magenta).
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pone.0131246.g006: M2 data from March through August 2011.(a) ice extent (%, black boxes) and thickness (blue triangles); (b) shallow (dark blue) and deep (cyan) temperature (° C); (c) shallow (red) and deep (magenta) salinity; (d) stratification (Δσ); (e) shallow (light green) and mid-column (dark green) Chl a fluorescence (μg L-1); (f) total scattering volume (Sv); (g) percent composition of classes of scatterers, including SmCrust (black), MdCrust (blue), LgCrust (red), WkReson (green), StReson (cyan), and Unclass (magenta).

Mentions: Ice was present until mid-May in 2011 (Fig 6A) as well, following a 4-day mid-winter ice retreat in February. This mid-winter ice retreat was accompanied by slight surface warming to a 7-day mean temperature of -0.7° C during the retreat (data not shown), followed by cooling to -0.8° C upon the return of ice. An initial increase in stratification began in early April 2011 (Fig 6D), likely a result of decreased salinity at shallow depths during that time (Fig 6C). However, stratification did not increase again until early June (Fig 6D) with increasing and decreasing temperature (Fig 6B) and salinity (Fig 6C), respectively, at shallow depths. Shallow and mid-column Chl a began to increase in late March and reached local maxima (11.8 μg L-1 and 13.2 μg L-1, respectively) within one day of each other in mid-April, approximately one month before ice retreat. (Fig 6E). Chl a decreased following these peaks until mid-May when smaller-scale increases in shallow Chl a (7.2 μg L-1) and mid-column Chl a (8.9 μg L-1) were observed, still 34 days before ice retreat. Shallow Chl a reached 18.5 μg L-1 in early June 2011, 20 days after ice retreat, while a later increase in mid-column Chl a to 6.0 μg L-1 in early June 2011 was less distinct.


Cold Regime interannual variability of primary and secondary producer community composition in the southeastern Bering Sea.

Stauffer BA, Miksis-Olds J, Goes JI - PLoS ONE (2015)

M2 data from March through August 2011.(a) ice extent (%, black boxes) and thickness (blue triangles); (b) shallow (dark blue) and deep (cyan) temperature (° C); (c) shallow (red) and deep (magenta) salinity; (d) stratification (Δσ); (e) shallow (light green) and mid-column (dark green) Chl a fluorescence (μg L-1); (f) total scattering volume (Sv); (g) percent composition of classes of scatterers, including SmCrust (black), MdCrust (blue), LgCrust (red), WkReson (green), StReson (cyan), and Unclass (magenta).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4482406&req=5

pone.0131246.g006: M2 data from March through August 2011.(a) ice extent (%, black boxes) and thickness (blue triangles); (b) shallow (dark blue) and deep (cyan) temperature (° C); (c) shallow (red) and deep (magenta) salinity; (d) stratification (Δσ); (e) shallow (light green) and mid-column (dark green) Chl a fluorescence (μg L-1); (f) total scattering volume (Sv); (g) percent composition of classes of scatterers, including SmCrust (black), MdCrust (blue), LgCrust (red), WkReson (green), StReson (cyan), and Unclass (magenta).
Mentions: Ice was present until mid-May in 2011 (Fig 6A) as well, following a 4-day mid-winter ice retreat in February. This mid-winter ice retreat was accompanied by slight surface warming to a 7-day mean temperature of -0.7° C during the retreat (data not shown), followed by cooling to -0.8° C upon the return of ice. An initial increase in stratification began in early April 2011 (Fig 6D), likely a result of decreased salinity at shallow depths during that time (Fig 6C). However, stratification did not increase again until early June (Fig 6D) with increasing and decreasing temperature (Fig 6B) and salinity (Fig 6C), respectively, at shallow depths. Shallow and mid-column Chl a began to increase in late March and reached local maxima (11.8 μg L-1 and 13.2 μg L-1, respectively) within one day of each other in mid-April, approximately one month before ice retreat. (Fig 6E). Chl a decreased following these peaks until mid-May when smaller-scale increases in shallow Chl a (7.2 μg L-1) and mid-column Chl a (8.9 μg L-1) were observed, still 34 days before ice retreat. Shallow Chl a reached 18.5 μg L-1 in early June 2011, 20 days after ice retreat, while a later increase in mid-column Chl a to 6.0 μg L-1 in early June 2011 was less distinct.

Bottom Line: Hydrographic conditions in 2012 were significantly different than in 2009, 2010, and 2011, driven largely by increased ice extent and thickness, later ice retreat, and earlier stratification of the water column.There was a high degree of variability in the relationships between different classes of secondary producers and hydrographic conditions, evidence of significant intra-consumer interactions, and trade-offs between different consumer size classes in each year.Overall, primary producers and secondary producers were more tightly coupled to each other and to hydrographic conditions in the coldest year compared to the warmer years.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology and Paleo Environment, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, 10964, United States of America.

ABSTRACT
Variability of hydrographic conditions and primary and secondary productivity between cold and warm climatic regimes in the Bering Sea has been the subject of much study in recent years, while interannual variability within a single regime and across multiple trophic levels has been less well-documented. Measurements from an instrumented mooring on the southeastern shelf of the Bering Sea were analyzed for the spring-to-summer transitions within the cold regime years of 2009-2012 to investigate the interannual variability of hydrographic conditions, primary producer biomass, and acoustically-derived secondary producer and consumer abundance and community structure. Hydrographic conditions in 2012 were significantly different than in 2009, 2010, and 2011, driven largely by increased ice extent and thickness, later ice retreat, and earlier stratification of the water column. Primary producer biomass was more tightly coupled to hydrographic conditions in 2012 than in 2009 or 2011, and shallow and mid-column phytoplankton blooms tended to occur independent of one another. There was a high degree of variability in the relationships between different classes of secondary producers and hydrographic conditions, evidence of significant intra-consumer interactions, and trade-offs between different consumer size classes in each year. Phytoplankton blooms stimulated different populations of secondary producers in each year, and summer consumer populations appeared to determine dominant populations in the subsequent spring. Overall, primary producers and secondary producers were more tightly coupled to each other and to hydrographic conditions in the coldest year compared to the warmer years. The highly variable nature of the interactions between the atmospherically-driven hydrographic environment, primary and secondary producers, and within food webs underscores the need to revisit how climatic regimes within the Bering Sea are defined and predicted to function given changing climate scenarios.

No MeSH data available.


Related in: MedlinePlus