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. "

Casault, B., Johnson, C.L., Devred, E., Clay, S., and Beazley, L. 2025. Chemical and Biological Oceanographic Conditions on the Scotian Shelf and in the Eastern Gulf of Maine during 2024. Can. Tech. Rep. Fish. Aquat. Sci. 3744: vi + 58 p. https://doi.org/10.60825/p6ad-1k52 Nutrient and plankton conditions were assessed in the context of physical conditions observed in the Maritimes Region in 2024. Nutrient depletion was widespread across the region, with Prince 5 (P5) station recording its tenth consecutive year of below-normal surface and subsurface nitrate inventories, while Cabot Strait section recorded record-low inventories for surface nitrate, silicate, and phosphate. Lower nutrient conditions likely influenced phytoplankton productivity, as chlorophyll-a measured in situ or derived from satellite remote sensing was mainly near or below normal across the region. The spring phytoplankton bloom was earlier than normal in the eastern area, near normal in the central area, and later than normal in the western area of the region. The intensity of the spring bloom was mainly normal to slightly below normal regionwide (except for Lurcher Shoal). The onset of the fall phytoplankton bloom was delayed across most areas, with the Eastern Scotian Shelf indicating a record-late onset. The intensity of the fall bloom was variable but mainly within near-normal ranges. Calanus finmarchicus abundance was near normal for the core sections, but negative and positive anomalies were recorded at the Halifax-2 (HL2) and P5 stations, respectively. Pseudocalanus spp. abundance reached record-high levels for the Halifax section, but was otherwise near normal. Mesozooplankton biomass was above normal at P5 but mainly below normal elsewhere, with record-low biomass observed at HL2. Arctic Calanus species and warm-water offshore copepods mainly remained at or below normal abundances, while warm-water shelf copepods showed near-normal abundances except for negative anomalies observed for the Halifax section and at P5.

Casault, B., Johnson, C.L., Devred, E., and Beazley, L. 2025. Chemical and Biological Oceanographic Conditions on the Scotian Shelf and in the Eastern Gulf of Maine during 2023. Can. Tech. Rep. Fish. Aquat. Sci. 3658: vi + 57 p. https://doi.org/10.60825/4d69-8120 Nutrient and plankton metrics are assessed in the context of physical conditions observed in the Maritimes region in 2023. Sub-surface (50-150 m) nitrate inventories were spatially variable across the region in 2023 but indicated a gradual return toward near-normal levels, except in the Bay of Fundy (i.e., at Prince-5) where a record-low value was observed in 2023. Bottom nitrate concentrations during summer were predominantly below normal across the region in 2023. In situ chlorophyll-a inventories were on average higher than normal in the region in 2023. Surface chlorophyll-a concentrations measured by satellite remote sensing reached record-high values in some sub-regions in 2023. The spring phytoplankton bloom timing was later than normal with a mainly lower-than-normal intensity in 2023. The fall bloom was generally earlier than normal with a higher-than-normal intensity. Diatoms abundance at Halifax-2 indicates increasing levels over the last three years. The abundance of Calanus finmarchicus was on average slightly above normal in the region in 2023, contrasting with the low abundances observed since 2011. Pseudocalanus spp. abundance was on average above normal in the region while zooplankton biomass and the abundance of Arctic Calanus species remained mainly near or below normal levels in 2023.

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

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 2014'. 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: The Atlantic Zone Monitoring Program (AZMP) derives its information on the marine environment and ecosystem from data collected at a network of sampling locations (fixed point, high frequency sampling stations, cross-shelf sections, ecosystem trawl surveys) in each Fisheries and Oceans Canada region (DFO; Québec, Gulf, Maritimes, and Newfoundland) sampled at a frequency of twice-monthly to once annually. This report provides an assessment of the distribution and variability of nutrients and plankton on the Scotian Shelf and in the eastern Gulf of Maine, focusing on conditions in 2014. Surface and deep ocean temperatures were warmer than average overall in the DFO Maritimes Region in 2014, especially in the slope waters and western Scotian Shelf in the second half of the year. Stratification was higher than average at an annual scale, but stratification anomalies were variable at sub-annual scales at the fixed stations and deep mixing events were observed at Halifax-2 in late winter and spring. Although annual average anomalies of surface- and deep-layer nitrate were near normal in most areas, there was substantial sub-annual variability in nitrate anomalies, particularly for deep-layer nitrate at Halifax-2. Scotian Shelf spring phytoplankton bloom magnitudes observed by remote sensing were low, while summer-fall blooms were higher than average in several areas. Spring blooms at the fixed stations were unusually deep, and therefore their magnitude would not have been accurately represented in satellite ocean colour observations. Both zooplankton biomass and Calanus finmarchicus abundance were lower than average overall in 2014. The abundance of Arctic Calanus species, an indicator of cold water on the Scotian Shelf, was lower than average in 2014, while the abundance of warm offshore species was higher than average on the central and western Scotian Shelf. Higher than average occurrence of thaliaceans (mainly salps) was observed, perhaps related to strong sub-annual variability. Ocean conditions in the DFO Maritimes Region have been characterized by strong sub-annual and mesoscale variability in 2013 and 2014, in addition to warmer temperatures, and interannual variability has been strong during the AZMP period since 1999. It is important to evaluate not only how the ecosystem responds to changes in mean conditions but also the response to changes in sub-annual to interannual variability. Continuous Plankton Recorder (CPR) sampling showed that in 2013 abundances of Calanus I-IV and C. finmarchicus V-VI returned to normal or relatively high levels from the historically low levels seen in 2012 across the Scotian Shelf. C. glacialis, C. hyperboreus and Oithona spp. were at near normal levels shelf-wide. Anomalies for three indices of phytoplankton abundance were below or close to normal on the Eastern Scotian Shelf (ESS) but above or close to normal on the Western Scotian Shelf (WSS). Many zooplankton taxa also exhibited contrasting patterns for the annual average abundance on the ESS versus the WSS. http://www.dfo-mpo.gc.ca/csas-sccs/Publications/ResDocs-DocRech/2016/2016_003-eng.html

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 2013'. 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: Ocean conditions were unusually warm and stratified on the Scotian Shelf in 2012, and the plankton response to the physical environment in 2012 set the initial conditions for the plankton in 2013. In particular, zooplankton biomass and the abundance of the two dominant herbivorous copepod species, Calanus finmarchicus and Pseudocalanus spp., were low, and there appeared to be a shift to a smaller-size phytoplankton community on the Scotian Shelf. In 2013, annual average temperature anomalies were still positive in the Maritimes Region, but less so than in 2012, and temperature and stratification anomalies were marked by strong sub-annual and mesoscale variability. Variability in the physical environment was reflected in nutrient and plankton conditions. Annual average deep-water and winter surface nitrate inventories were similar to average overall, but surface nitrate was higher than average. The magnitude of the spring bloom chlorophyll peak was above average on the Eastern Scotian Shelf (ESS) and below average on the Western Scotian Shelf (WSS) and in the eastern Gulf of Maine, but summer-fall blooms were above average in all areas. Zooplankton biomass and abundance were lower than average on the eastern transects, but anomalies were mixed on the Central Scotian Shelf, ESS and Bay of Fundy. The abundance of Pseudocalanus spp. was higher than average in the central and western part of the region. Although C. finmarchicus abundance was variable and lower than average overall, it was high on the WSS and in the eastern Gulf of Maine during the summer ecosystem trawl survey and higher than average at the Halifax-2 station and in Emerald Basin in autumn, suggesting a return to more typical abundances in the western part of the region at the end of 2013. Similar to the broader Scotian Shelf, the 2013 Bedford Basin annual average temperature was warmer than normal but not as warm as 2012. Small phytoplankton were more abundant than average in Bedford Basin and large phytoplankton less abundant. An initial evaluation of relationships among annual anomalies of physical variables, nitrate, spring bloom metrics and zooplankton at Halifax-2 from 1999 to 2013 identified bloom duration and enhanced upwelling as important correlates of zooplankton biomass and dominant copepod abundance at an annual scale. Continuous Plankton Recorder sampling showed that observations of phytoplankton bloom dynamics and abundance of C. finmarchicus at Halifax-2 in 2012 were representative of shelf-wide patterns. http://www.dfo-mpo.gc.ca/csas-sccs/Publications/ResDocs-DocRech/2014/2014_104-eng.html

This dataset contains raw sampling data beginning in 1989 for a long-term environmental and seagrass monitoring station in Laguna Madre (“LM-151”). This project served to understand environmental drivers of long-term changes in seagrass condition within the Upper Laguna Madre, Texas. Environmental parameters measured within the water column include water depth, dissolved oxygen concentration, underwater light level, pH, salinity, Secchi depth (turbidity), water temperature, total suspended solids, and dissolved inorganic nitrogen and ammonium. Seagrass biological parameters measured are above/belowground biomass and shoot density. Typical seagrass species represented within the data include Halodule wrightii (shoal grass) and Syringodium filiforme (manatee grass). Sampling was dependent on funding/resource availability and local weather conditions, therefore temporal gaps in data may exist. Data are provided in CSV format.

Mean 2014 to 2023 winter surface conditions in the Estuary and Gulf of St. Lawrence. The survey has been taking place every year in March. Surface conditions are described by temperature, salinity and nutrient concentration (mmol/m3) interpolated on a 10km x 10km grid. Purpose Since many years, the Department of Fisheries and Oceans Canada (DFO) has been conducting annual surveys, at different periods of the year, in the Estuary and Gulf of St. Lawrence, each having many objectives including assessment of environmental conditions. However, these surveys, carried out on vessels, did not cover the winter period. Since 1996, a regional monitoring program, conducted by Maurice-Lamontagne Institute scientists, is taking place in order to fill this gap. The annual helicopter survey is undertaken in the beginning of March to evaluate physical oceanographic conditions of waters up to 200 m and surface water nutrient contains. These surveys are usually sampled from a Canadian Coast Guard helicopter but from an icebreaker in 2016 and 2017. Data from regional monitoring programs are combined with the ones from the Atlantic Zone Monitoring Program (AZMP) to produce annual reports (physical, biological and a Zonal Scientific Advice) which are available at the Canadian Science Advisory Secretariat (CSAS), (http://www.dfo-mpo.gc.ca/csas-sccs/index-eng.htm). Galbraith, P.S., Chassé, J., Caverhill, C., Nicot, P., Gilbert, D., Pettigrew, B., Lefaivre, D., Brickman, D., Devine, L., and Lafleur, C. 2017. Physical Oceanographic Conditions in the Gulf of St. Lawrence in 2016. DFO Can. Sci. Advis. Sec. Res. Doc. 2017/044. v + 91 p. Devine, L., Scarratt, M., Plourde, S., Galbraith, P.S., Michaud, S., and Lehoux, C. 2017. Chemical and Biological Oceanographic Conditions in the Estuary and Gulf of St. Lawrence during 2015. DFO Can. Sci. Advis. Sec. Res. Doc. 2017/034. v + 48 pp. Additional Information Water sampling for nutrient analysis is done from Niskin bottles according to AZMP sampling protocol: Mitchell, M. R., Harrison, G., Pauley, K., Gagné, A., Maillet, G., and Strain, P. 2002. Atlantic Zonal Monitoring Program sampling protocol. Can. Tech. Rep. Hydrogr. Ocean Sci. 223: iv + 23 pp. Nitrate titration is carried out according to the following method ((nitrite + nitrate) – nitrite): Nitrite + nitrate: Armstrong, FAJ, CR Stearns, JDH Strickland (1967) The measurement of upwelling and subsequent biological processes by means of the Technicon Autoanalyzer and associated equipment. Deep-Sea Res 14(3) 381-389. Nitrite: American Public Health Assoc. (1971) Standard Methods for the examination of water and wastewater. 13th edition, pp. 240-243, Washington D.C. Phosphate: Murphy, J, JP Riley (1962) A modified single solution method for the determination of phosphate in natural waters. Anal Chim. Acta 27 : 30. Silicate: Strickland, JDH, TR Parsons (1972) A Practical Handbook of Seawater Analysis, second edition. Fish Res Board Can, Bulletin 167, 310 pp. The surface water temperature and salinity are determined from CTD profiles.