Optical, chemical, and biological oceanographic conditions on the Scotian Shelf and in the eastern Gulf of Maine in 2012

Optical, chemical, and biological oceanographic conditions on the Scotian Shelf and in the eastern Gulf of Maine in 2012 This entry provides access to the figures and data tables that feature in the CSAS Research Document titled 'Optical, chemical, and biological oceanographic conditions on the Scotian Shelf and in the eastern Gulf of Maine in 2012'. Please consult the meta-data text file that accompanies the zip file download for the figure on the data usage policy and appropriate citation. The meta-data file also provides field descriptors and any other information that may be useful in interpreting the data provided in relation to the accompanying imagery. Abstract: In 2012, anomalously warm ocean temperatures throughout the water column on the Scotian Shelf and eastern Gulf of Maine influenced the chemical and biological conditions of the region. Stratification was higher than average on the Scotian Shelf. At the Halifax-2 fixed station, upper water column (0-50 m) nitrate was lower than normal throughout 2012, while deep water (50-150 m) nitrate concentrations were much higher than normal, suggesting that stratification may have inhibited nutrient mixing into the upper water column. Deep water nitrate concentrations were also higher than average throughout most of the region. Spring bloom initiation timing at Halifax-2 was about average, and the bloom was average in magnitude but short in duration, but winter chlorophyll concentrations were higher than average. Satellite ocean color observations also indicated high winter chlorophyll concentrations and early and/or short spring bloom timing across much of the Scotian Shelf. Although chlorophyll concentrations were about average following the spring bloom at Halifax-2, light attenuation was high, cell abundances were low, and diatoms and dinoflagellates were less relatively abundant and flagellates and ciliates more relatively abundant than normal, suggesting a shift to a smaller-sized phytoplankton community, possibly including higher than average concentrations of picoplankton. At the Prince-5 fixed station, the seasonal chlorophyll cycle was similar to normal, but chlorophyll values were higher than average in July and August, when chain forming diatoms (July) and dinoflagellates (August) were abundant. Satellite ocean colour indicated higher than average surface chlorophyll across the eastern Gulf of Maine in August and September. Zooplankton biomass was very low at Halifax-2 throughout 2012, and it was also low on all shelf sections in fall. At Prince-5, zooplankton biomass was mostly low in the first half of the year but rebounded in the fall. At both fixed stations,Calanus finmarchicus abundances were low everywhere throughout 2012. C. finmarchicus production was likely impacted by its low abundance at the end of 2011 and high temperatures experienced by the dormant stock during the fall and winter of 2011/2012. At Halifax-2, a short phytoplankton bloom and low diatom abundance may have also contributed to low abundances of C. finmarchicus and Pseudocalanus spp. during 2012. Transient high abundances of small-particle-feeding zooplankton taxa (appendicularians, salps, pteropods) were observed both on the Scotian Shelf and at Prince-5. Cold-associated immigrant species (Arctic Calanus) were less abundant and warm offshore species generally more abundant than average in 2012, consistent with warmer temperatures and model estimates of changes in circulation. Overall, lower trophic level changes in 2012 suggest poor feeding conditions for planktivores on the Scotian Shelf, but the late summer-early fall bloom in the eastern Gulf of Maine and Bay of Fundy may have been favorable for some higher trophic level species. http://www.dfo-mpo.gc.ca/csas-sccs/Publications/ResDocs-DocRech/2013/2013_070-eng.html 2017-12-12 Fisheries and Oceans Canada catherine.johnson@dfo-mpo.gc.ca Form DescriptorsNature and EnvironmentScience and TechnologyPlanktonChlorophyllNutrientsEarth sciencesOceanographyWaterEnvironmental sciencesSalt waterCoastal watersOceansMarine biology Fig 06 : Mixing properties at the fixed stationsZIP http://www.meds-sdmm.dfo-mpo.gc.ca/isdm-gdsi/azmp-pmza/document-data-donnees-documents/data/CSAS_2013_070_fig_6.zip Fig 07 : Optical properties at the fixed stationsZIP http://www.meds-sdmm.dfo-mpo.gc.ca/isdm-gdsi/azmp-pmza/document-data-donnees-documents/data/CSAS_2013_070_fig_7.zip Fig 09 : Nitrate inventories at the fixed stationsZIP http://www.meds-sdmm.dfo-mpo.gc.ca/isdm-gdsi/azmp-pmza/document-data-donnees-documents/data/CSAS_2013_070_fig_9.zip Fig 10 : Maritimes region chemical and biological environment anomaly scorecardZIP http://www.meds-sdmm.dfo-mpo.gc.ca/isdm-gdsi/azmp-pmza/document-data-donnees-documents/data/CSAS_2013_070_fig_10.zip Fig 13 : Chlorophyll inventories at the fixed stationsZIP http://www.meds-sdmm.dfo-mpo.gc.ca/isdm-gdsi/azmp-pmza/document-data-donnees-documents/data/CSAS_2013_070_fig_13.zip Fig 14 : Spring phytoplankton bloom magnitude, timing and durationZIP http://www.meds-sdmm.dfo-mpo.gc.ca/isdm-gdsi/azmp-pmza/document-data-donnees-documents/data/CSAS_2013_070_fig_14.zip Fig 15 : Microplankton abundance and community composition at the fixed stationsZIP http://www.meds-sdmm.dfo-mpo.gc.ca/isdm-gdsi/azmp-pmza/document-data-donnees-documents/data/CSAS_2013_070_fig_15.zip Fig 17 : Zooplankton biomass at the fixed stationsZIP http://www.meds-sdmm.dfo-mpo.gc.ca/isdm-gdsi/azmp-pmza/document-data-donnees-documents/data/CSAS_2013_070_fig_17.zip Fig 18 : Zooplankton abundance and community composition at the fixed stationsZIP http://www.meds-sdmm.dfo-mpo.gc.ca/isdm-gdsi/azmp-pmza/document-data-donnees-documents/data/CSAS_2013_070_fig_18.zip Fig 19 : Calanus finmarchicus abundance and stage distribution at the fixed stationsZIP http://www.meds-sdmm.dfo-mpo.gc.ca/isdm-gdsi/azmp-pmza/document-data-donnees-documents/data/CSAS_2013_070_fig_19.zip Fig 20 : Dominant copepods abundanceZIP http://www.meds-sdmm.dfo-mpo.gc.ca/isdm-gdsi/azmp-pmza/document-data-donnees-documents/data/CSAS_2013_070_fig_20.zip Fig 21 : Immigrant copepods groups abundance anomaly scorecardZIP http://www.meds-sdmm.dfo-mpo.gc.ca/isdm-gdsi/azmp-pmza/document-data-donnees-documents/data/CSAS_2013_070_fig_21.zip Fig 22a : Zooplankton biomass - AZMP sectionsZIP http://www.meds-sdmm.dfo-mpo.gc.ca/isdm-gdsi/azmp-pmza/document-data-donnees-documents/data/CSAS_2013_070_fig_22a.zip Fig 22b : Calanus finmarchicus abundance - AZMP sectionsZIP http://www.meds-sdmm.dfo-mpo.gc.ca/isdm-gdsi/azmp-pmza/document-data-donnees-documents/data/CSAS_2013_070_fig_22b.zip Fig 23a : Zooplankton biomass - Ecosystem trawl surveysZIP http://www.meds-sdmm.dfo-mpo.gc.ca/isdm-gdsi/azmp-pmza/document-data-donnees-documents/data/CSAS_2013_070_fig_23a.zip Fig 23b : Calanus finmarchicus abundance - Ecosystem trawl surveysZIP http://www.meds-sdmm.dfo-mpo.gc.ca/isdm-gdsi/azmp-pmza/document-data-donnees-documents/data/CSAS_2013_070_fig_23b.zip Fig 24 : Bedford Basin temperature, salinity, stratification, chlorophyll, picoeukaryotes abundance and Synechococcus abundance anomaly time seriesZIP http://www.meds-sdmm.dfo-mpo.gc.ca/isdm-gdsi/azmp-pmza/document-data-donnees-documents/data/CSAS_2013_070_fig_24.zip

This entry provides access to the figures and data tables that feature in the CSAS Research Document titled 'Optical, chemical, and biological oceanographic conditions on the Scotian Shelf and in the eastern Gulf of Maine in 2012'. Please consult the meta-data text file that accompanies the zip file download for the figure on the data usage policy and appropriate citation. The meta-data file also provides field descriptors and any other information that may be useful in interpreting the data provided in relation to the accompanying imagery. Abstract: In 2012, anomalously warm ocean temperatures throughout the water column on the Scotian Shelf and eastern Gulf of Maine influenced the chemical and biological conditions of the region. Stratification was higher than average on the Scotian Shelf. At the Halifax-2 fixed station, upper water column (0-50 m) nitrate was lower than normal throughout 2012, while deep water (50-150 m) nitrate concentrations were much higher than normal, suggesting that stratification may have inhibited nutrient mixing into the upper water column. Deep water nitrate concentrations were also higher than average throughout most of the region. Spring bloom initiation timing at Halifax-2 was about average, and the bloom was average in magnitude but short in duration, but winter chlorophyll concentrations were higher than average. Satellite ocean color observations also indicated high winter chlorophyll concentrations and early and/or short spring bloom timing across much of the Scotian Shelf. Although chlorophyll concentrations were about average following the spring bloom at Halifax-2, light attenuation was high, cell abundances were low, and diatoms and dinoflagellates were less relatively abundant and flagellates and ciliates more relatively abundant than normal, suggesting a shift to a smaller-sized phytoplankton community, possibly including higher than average concentrations of picoplankton. At the Prince-5 fixed station, the seasonal chlorophyll cycle was similar to normal, but chlorophyll values were higher than average in July and August, when chain forming diatoms (July) and dinoflagellates (August) were abundant. Satellite ocean colour indicated higher than average surface chlorophyll across the eastern Gulf of Maine in August and September. Zooplankton biomass was very low at Halifax-2 throughout 2012, and it was also low on all shelf sections in fall. At Prince-5, zooplankton biomass was mostly low in the first half of the year but rebounded in the fall. At both fixed stations,Calanus finmarchicus abundances were low everywhere throughout 2012. C. finmarchicus production was likely impacted by its low abundance at the end of 2011 and high temperatures experienced by the dormant stock during the fall and winter of 2011/2012. At Halifax-2, a short phytoplankton bloom and low diatom abundance may have also contributed to low abundances of C. finmarchicus and Pseudocalanus spp. during 2012. Transient high abundances of small-particle-feeding zooplankton taxa (appendicularians, salps, pteropods) were observed both on the Scotian Shelf and at Prince-5. Cold-associated immigrant species (Arctic Calanus) were less abundant and warm offshore species generally more abundant than average in 2012, consistent with warmer temperatures and model estimates of changes in circulation. Overall, lower trophic level changes in 2012 suggest poor feeding conditions for planktivores on the Scotian Shelf, but the late summer-early fall bloom in the eastern Gulf of Maine and Bay of Fundy may have been favorable for some higher trophic level species. http://www.dfo-mpo.gc.ca/csas-sccs/Publications/ResDocs-DocRech/2013/2013_070-eng.html

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City: Dartmouth

Administrative Area: Nova Scotia

Country: Canada

Electronic Mail Address: catherine.johnson@dfo-mpo.gc.ca

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