Optical, chemical, and biological oceanographic conditions on the Scotian Shelf and in the eastern Gulf of Maine in 2019

Optical, chemical, and biological oceanographic conditions on the Scotian Shelf and in the eastern Gulf of Maine in 2019 Ocean physical conditions in the Maritimes Region in 2019 were characterized by cooler surface temperatures, continued warmer bottom temperatures and weaker stratification compared to recent years. Deep nutrient inventories were lower than normal over most of the region, with the exception of the Cabot Strait section where deep nutrients were near or higher than normal during the spring sampling and associated with record-warm water. Anomalies of surface nutrients were negative across the region, with the exception of positive anomalies observed at the deep shelf and offshore stations of the Louisbourg section. The spring phytoplankton bloom was near or slightly earlier than normal across the Scotian Shelf (SS) with near-normal duration. Peak chlorophyll a concentrations during the spring bloom occurred within a narrow time window across the SS. At Halifax-2 (HL2), the spring bloom was characterized by a high amplitude, and a rapid progression and decline. Plankton community changes persisted in 2019 with lower abundance of large phytoplankton (diatoms), mainly lower-than-normal biomass of zooplankton and abundance of Calanus finmarchicus, and higher-than-normal abundance of non-copepods. Arctic Calanus and warm-shelf copepods showed mixed abundance anomalies in 2019, reversing the pattern of 2018. Above-normal abundances of Oithona atlantica, especially at HL2, suggest a greater influence of offshore waters in recent years. Surface temperature in the Bedford Basin was near normal in 2019 with mainly cooler-than-normal temperatures from January to June and near- or slightly-above-normal temperatures from July to December. Bottom temperature and salinity were below normal in 2019 with near- or slightly-above-normal conditions at the start of the year and progressing toward cooler and fresher water from February to December. Surface and deep nitrate, phosphate and silicate were near or below normal, with surface phosphate reaching a record low in 2019. The 2018 Continuous Plankton Recorder data indicated an annual abundance of diatoms close to normal for the Eastern (ESS) and Western Scotian Shelf (WSS), while the abundance of dinoflagellates and the Phytoplankton Colour Index values were near (WSS) or above (ESS) normal. The annual abundance of Calanus CI-IV was near normal (ESS) or slightly below normal (WSS), while C. finmarchicus CV-VI levels were slightly below (ESS) or below (WSS) normal. The abundance of Calanus glacialis (ESS, WSS) and Para/Pseudocalanus and Limacina spp. (WSS) were lower than normal, while that of coccolithphore (ESS, WSS), and copepod nauplii and foraminifera (ESS) was higher than normal. " 2021-05-19 Fisheries and Oceans Canada catherine.johnson@dfo-mpo.gc.ca Nature and EnvironmentChlorophyllNutrientsPlanktonMarine biologyCoastal watersEarth sciencesSalt waterOceansWaterOceanography Figure 06 : Mixing properties at the fixed stations (English)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_6_en.pdf Figure 06 : Mixing properties at the fixed stations (French)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_6_fr.pdf Figure 08 : Optical properties at the fixed stations (English)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_8_en.pdf Figure 08 : Optical properties at the fixed stations (French)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_8_fr.pdf Figure 10 : Nitrate inventories at the fixed stations (English)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_10_en.pdf Figure 10 : Nitrate inventories at the fixed stations (French)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_10_fr.pdf Figure 11 : Maritimes region nutrients anomaly scorecard (English)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_11_en.pdf Figure 11 : Maritimes region nutrients anomaly scorecard (French)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_11_fr.pdf Figure 15 : Chlorophyll inventories at the fixed stations (English)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_15_en.pdf Figure 15 : Chlorophyll inventories at the fixed stations (French)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_15_fr.pdf Figure 16 : Microplankton abundance and community composition at the fixed stations (English)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_16_en.pdf Figure 16 : Microplankton abundance and community composition at the fixed stations (French)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_16_fr.pdf Figure 17 : Maritimes region plankton anomaly scorecard (English)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_17_en.pdf Figure 17 : Maritimes region plankton anomaly scorecard (French)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_17_fr.pdf Figure 18 : Microplankton abundance anomaly scorecard at the fixed stations (English)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_18_en.pdf Figure 18 : Microplankton abundance anomaly scorecard at the fixed stations (French)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_18_fr.pdf Figure 21: Maritimes region microplankton pigments anomaly scorecard (English)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_21_en.pdf Figure 21: Maritimes region microplankton pigments anomaly scorecard (French)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_21_fr.pdf Figure 22 : Zooplankton biomass at the fixed stations (English)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_22_en.pdf Figure 22 : Zooplankton biomass at the fixed stations (French)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_22_fr.pdf Figure 23 : Zooplankton abundance and community composition at the fixed stations (English)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_23_en.pdf Figure 23 : Zooplankton abundance and community composition at the fixed stations (French)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_23_fr.pdf Figure 24 : Calanus finmarchicus abundance and stage distribution at the fixed stations (French)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_24_fr.pdf Figure 24 : Calanus finmarchicus abundance and stage distribution at the fixed stations (English)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_24_en.pdf Figure 25: Dominant copepods abundance at Prince-5 and Halifax 2 stations (English)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_25_en.pdf Figure 25: Dominant copepods abundance at Prince-5 and Halifax 2 stations (French)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_25_fr.pdf Figure 26 : Zooplankton biomass - AZMP sections (English)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_26_en.pdf Figure 26 : Zooplankton biomass - AZMP sections (French)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_26_fr.pdf Figure 27 : Zooplankton biomass - Ecosystem trawl surveys (English)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_27_en.pdf Figure 27 : Zooplankton biomass - Ecosystem trawl surveys (French)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_27_fr.pdf Figure 28 : Calanus finmarchicus abundance - AZMP sections (English)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_28_en.pdf Figure 28 : Calanus finmarchicus abundance - AZMP sections (French)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_28_fr.pdf Figure 29 : Calanus finmarchicus abundance - Ecosystem trawl surveys (English)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_29_en.pdf Figure 29 : Calanus finmarchicus abundance - Ecosystem trawl surveys (French)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_29_fr.pdf Figure 30 : Non-copepods abundance anomaly scorecard - Scotian Shelf (English)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_30_en.pdf Figure 30 : Non-copepods abundance anomaly scorecard - Scotian Shelf (French)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_30_fr.pdf Figure 31 : Maritimes region indicator copepods groups abundance anomaly scorecard (English)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_31_en.pdf Figure 31 : Maritimes region indicator copepods groups abundance anomaly scorecard (French)PDF https://pacgis01.dfo-mpo.gc.ca/FGPPublic/Optical_Chemical_Biological_Oceanographic_Conditions_Scotian_Shelf_Eastern_Gulf_Maine_2019/pdf/CSAS_2020_071_Figure_31_fr.pdf Research DocumentHTML https://www.dfo-mpo.gc.ca/csas-sccs/Publications/ResDocs-DocRech/2020/2020_071-eng.html Research DocumentHTML https://www.dfo-mpo.gc.ca/csas-sccs/Publications/ResDocs-DocRech/2020/2020_071-fra.html

Ocean physical conditions in the Maritimes Region in 2019 were characterized by cooler surface temperatures, continued warmer bottom temperatures and weaker stratification compared to recent years. Deep nutrient inventories were lower than normal over most of the region, with the exception of the Cabot Strait section where deep nutrients were near or higher than normal during the spring sampling and associated with record-warm water. Anomalies of surface nutrients were negative across the region, with the exception of positive anomalies observed at the deep shelf and offshore stations of the Louisbourg section. The spring phytoplankton bloom was near or slightly earlier than normal across the Scotian Shelf (SS) with near-normal duration. Peak chlorophyll a concentrations during the spring bloom occurred within a narrow time window across the SS. At Halifax-2 (HL2), the spring bloom was characterized by a high amplitude, and a rapid progression and decline. Plankton community changes persisted in 2019 with lower abundance of large phytoplankton (diatoms), mainly lower-than-normal biomass of zooplankton and abundance of Calanus finmarchicus, and higher-than-normal abundance of non-copepods. Arctic Calanus and warm-shelf copepods showed mixed abundance anomalies in 2019, reversing the pattern of 2018. Above-normal abundances of Oithona atlantica, especially at HL2, suggest a greater influence of offshore waters in recent years. Surface temperature in the Bedford Basin was near normal in 2019 with mainly cooler-than-normal temperatures from January to June and near- or slightly-above-normal temperatures from July to December. Bottom temperature and salinity were below normal in 2019 with near- or slightly-above-normal conditions at the start of the year and progressing toward cooler and fresher water from February to December. Surface and deep nitrate, phosphate and silicate were near or below normal, with surface phosphate reaching a record low in 2019. The 2018 Continuous Plankton Recorder data indicated an annual abundance of diatoms close to normal for the Eastern (ESS) and Western Scotian Shelf (WSS), while the abundance of dinoflagellates and the Phytoplankton Colour Index values were near (WSS) or above (ESS) normal. The annual abundance of Calanus CI-IV was near normal (ESS) or slightly below normal (WSS), while C. finmarchicus CV-VI levels were slightly below (ESS) or below (WSS) normal. The abundance of Calanus glacialis (ESS, WSS) and Para/Pseudocalanus and Limacina spp. (WSS) were lower than normal, while that of coccolithphore (ESS, WSS), and copepod nauplii and foraminifera (ESS) was higher than normal. "

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Geographic Information

Spatial Feature

Contact Information

Delivery Point: Bedford Institute of Oceanography, 1 Challenger Drive, PO Box 1006

City: Dartmouth

Administrative Area: Nova Scotia

Postal Code: B2Y 4A2

Country: Canada

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

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