2023 Northeast Spring Ecosystem Monitoring Cruise Completed
The research team completed all of the planned stations from Cape Hatteras, North Carolina, to Georges Bank and through the Gulf of Maine. They also collected data in wind energy lease areas.
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Our ecosystem monitoring cruises help researchers understand and predict changes in the Northeast shelf ecosystem and its fisheries. Our core sampling provides data that help us understand ocean acidification as well as changes in:
- Distribution and abundance of zooplankton and larval fish
- Temperature
- Salinity
Researchers also record observations of seabirds, marine mammals, and sea turtles. Egg data collected are important for managing Atlantic mackerel in U.S. and Canadian waters.
We sampled 222 stations from June 8 to 28, 2023. We completed 100 percent of our planned research activities and collected supplemental data, thanks to a full complement of 21 sea days, great weather, and efficient crew and command. Making the most of our time at sea, we conducted three supplemental sampling efforts to aid several of our science center's projects.
The plankton we gather provide information about the food chain supporting fisheries and marine mammals. Scientists use our larval fish and egg samples to learn more about fish stock spawning and help estimate stock abundance. By measuring physical and chemical conditions like temperature and salinity, we can describe:
- Ecosystem productivity
- Fish spawning
- Larval recruitment
- Species distribution
![A map of the North Atlantic Ocean off of Cape Cod, Massachusetts, Maine, and Nova Scotia. Blue dots along a blue line show two tracks, one closer to Maine and one off the coast of Massachusetts.]()
Station layout and proposed track line for the northern part of the 2023 Ecomon survey. Credit: NOAA Fisheries, Office of Marine and Aviation Operations/Shelley Rofrits
Core Sampling Summary
Plankton Collection
During this survey, we conducted “bongo” net tows at 195 different stations. We attached fine-mesh nets to adjoined aluminum rings, creating a sampling device that resembles bongo drums when deployed. Bongo net tows collect zooplankton, larval fish, and fish eggs. Researchers will use samples from this survey to update an index of Atlantic mackerel egg abundance used in the stock assessment for this species.
We conducted three supplemental sampling efforts to aid ongoing projects in our science center. We collected plankton and hydrographic data in the central Gulf of Maine to help evaluate the effect of an earlier strong crossover event of water from the Scotian Shelf to the Northeast Channel and Georges Bank regions. Scientists will use these data in the State of the Ecosystem reports and right whale foraging studies.
We also completed cross-shelf transects through two warmcore eddies offshore of Great South Channel and Nantucket Shoals. We collected plankton samples, hydrographic data, and water samples for nutrient, chlorophyll, and dissolved inorganic carbon analyses. All will be used to explore the location and directions of cross-shelf exchange from the slope waters to the shelf and the potential impacts to the ecosystem, including habitat use by squid, bluefin tuna, and baleen whales.
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Finally, we sampled fixed plankton stations in wind energy lease areas near Nantucket Shoals multiple times across different tidal stages. We will examine plankton communities in relation to current data collected with the ship’s Acoustic Doppler Current Profiler to look at pre-construction patterns among zooplankton and tidal currents. Data will directly help the science center's efforts to understand the impacts of wind energy development in the region.
Conductivity, Temperature, and Depth Profiles
The crew deployed instruments that can measure conductivity, temperature, and depth at all 222 stations on this survey. Seawater conducts electricity. Conductivity varies with the amount of dissolved salts in the ocean, and scientists use it to estimate the salinity of seawater. The combination of temperature and salinity at various depths helps define marine habitat boundaries, track ocean circulation, and monitor changes in climate. This can help explain changes in marine species distribution and productivity.
Ocean Acidification Monitoring
To monitor marine carbon cycling and ocean acidification, scientists collected water samples at 52 stations and measured:
- Dissolved inorganic carbon
- Total alkalinity
- pH
- Nutrient concentrations
Increases in dissolved carbon dioxide can increase the acidity of the water, which can affect shellfish and other sensitive organisms. The NOAA Ocean Acidification Program funded this work. We conducted it in partnership with NOAA’s Atlantic Oceanographic and Meteorological Laboratory in Miami, Florida.
The crew also collected pteropods—tiny planktonic snails—from the water column. Researchers will examine the condition of the pteropod shells to measure the biological effects of ocean acidification. We expanded our plankton net tows to include the chemistry stations in the Mid-Atlantic Bight to facilitate pteropod sampling alongside carbonate chemistry measurements. We also took supplemental surface carbonate chemistry samples at any plankton station where we saw pteropods.
We conduct pteropod measurements in partnership with the Bermuda Institute of Ocean Science, where the measurement technique that we use was developed by Dr. Amy Maas.
Special Collection Summary
We collaborate with other agencies and institutions that support research which enhances our core sampling.
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Visual Sighting
Two trained observers watched for and recorded data on seabirds, marine mammals, and sea turtles we encountered along the cruise track. This is part of the Atlantic Marine Assessment Program for Protected Species.
Phytoplankton Monitoring
We deployed an imaging flow cytobot to image and count phytoplankton cells from surface waters throughout the ship’s transit. This work is part of a National Science Foundation project led by Woods Hole Oceanographic Institution in collaboration with NOAA Fisheries. The imaging flow cytobot was especially useful in documenting a large dinoflagellate bloom that occurred over a large swath of the survey area.
Ocean Temperature and Current Tracking
We deployed two buoys from the NOAA Global Drifter Program while working on the northeast part of Georges Bank (track drifter buoys #5301663 and 5301666). The buoys have been continuously transmitting their positions and water temperatures and those data are available for free to students and researchers on the NOAA AOML interactive map of the global drifter array.
Satellite Imagery and Water Column Radiometry
On days when skies were clear, we lowered a submersible light sensor into the water to measure subsurface light levels while a satellite was passing over in the middle of the day. These measurements will provide ground-truthing data for scientists to evaluate the algorithms used by satellites to determine sea-surface temperatures.
Community and Primary Production
We used plankton nets to collect subsamples of plankton for stable isotope analysis for an ongoing collaborative study with the University of Rhode Island. This project is examining the spatial distribution of plankton carbon and nitrogen isotopes in the offshore samples and comparing them with results obtained from samples taken from Narragansett Bay and Block Island Sound.
A researcher from our Narragansett Laboratory took subsamples of plankton to determine their energy content. These samples will help determine if different preservation methods—storing in formaldehyde or drying—can affect the energy determination analyses.
Outreach
We hosted two college students on this cruise, one from Endicott College and one from the University of New England. The students participated in all aspects of the data and sample collection. We sent updates and photos of their experiences to their academic advisors for inclusion in their college transcripts.