A delayed start, good coverage of planned stations in the northern survey area, dropped stations in the south.
Teacher-at-sea Tonya Prentice (foreground) and Knauss Fellow Karen Beatty (background) washing down plankton sampling nets after a deployment. Credit: NOAA Fisheries/Chris Melrose.
Our ecosystem monitoring cruises help researchers understand and predict changes in the Northeast shelf ecosystem and its fisheries throughout the year. 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.
We sampled 111 of 162 planned stations from August 12 to 23 aboard the NOAA Ship Henry B. Bigelow. Sailing was delayed from the originally scheduled departure on August 9 so the vessel could replace an essential crew member on short notice. We completed 68.5 percent of our planned research activities. We dropped stations from New Jersey to North Carolina owing to delayed sailing, and focused on stations in the Gulf of Maine, Georges Bank, and Southern New England.
Chart showing location of planned and completed stations by type and completion rates by area for the Summer 2024 Ecosystem Monitoring Survey. Credit: NOAA Fisheries
Core Sampling Summary
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.
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Conductivity, Temperature, and Depth Profiles
The crew deployed instruments that can measure conductivity, temperature, and depth at all 111 stations. 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 24 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.
Comparative Plankton Sampling
We conducted paired sampling using EcoMon bongo tows and Division of Fisheries Ocean, Canada’s Atlantic Zone Monitoring Program ring net to compare samples collected using each program’s gear.
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NOAA Fisheries, 17 September 2024. Full article.
