2024 Northeast Spring Ecosystem Monitoring Cruise Completed
Sampling was expanded off the Mid-Atlantic to capture more plankton for studying ocean acidification.
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
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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 131 stations from May 25–28 and June 3–14, 2024. We lost 4.5 operational days due to an unexpected mechanical issue with the fast rescue boat. We completed 79 percent of our planned research activities. We dropped stations in the most southern and northern portions of the cruise to allow for the most efficient cruise track.
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
Core Sampling Summary
Plankton Collection
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During this survey, we conducted bongo net tows at 122 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 plankton sampling around five offshore wind lease areas:
- Liberty Wind
- Mayflower Wind
- Sunrise Wind
- Bay State Wind
- Revolution Wind
Conductivity, Temperature, and Depth Profiles
The crew deployed instruments that can measure conductivity, temperature, and depth at all 131 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 28 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; the measurement technique 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.
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.
Outreach
We hosted two college students on this cruise from the Massachusetts Maritime Academy. The students participated in all aspects of the data and sample collection.