2024 Northeast Winter Ecosystem Monitoring Cruise Completed

Image

Cruise Summary 

Between February 16 and February 22 we visited 39 stations aboard the NOAA Ship Henry B. Bigelow. That’s 31 percent of the coverage originally planned for this winter’s Ecosystem Monitoring Survey. Ship propulsion issues delayed the cruise start by 7 days, half of our allotted cruise time. As a result, we dropped planned stations north of Stellwagen Bank and south of the Hudson River Valley, between Hudson Canyon and Cape Hatteras, North Carolina. 

To make the most of the time available once underway we altered our cruise track. We prioritized collecting depth-discrete water samples for ocean acidification monitoring, and plankton sampling around offshore wind energy lease areas. 

We sailed through the Cape Cod Canal to start sampling in the southern Gulf of Maine. We then lost another half day sampling to a strong storm system, which affected station coverage and deployments in the Great South Channel and Nantucket Shoals. Calm seas the last 3 days of the cruise allowed the science team and ship’s crew to sample portions of southern New England. We also sampled around some offshore wind energy areas, where we saw North Atlantic right whales. 

Our EcoMon cruises help researchers understand and predict changes in the Northeast shelf ecosystem and its fisheries and protected species. We collect data used to monitor the distribution and abundance of zooplankton and larval fish, water temperature and salinity, and ocean acidification. Researchers also collect observations of seabirds, marine mammals, and sea turtles.

The plankton—tiny animals and young stages of some larger ones—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, spawning, larval recruitment, fish condition, and species distributions. 

Core Sampling Summary

Plankton Collection

During this survey, we conducted “bongo” net tows at 39 stations. We attach fine-mesh nets to adjoined steel rings, causing them to resemble bongo drums when deployed. Bongo net tows collect zooplankton, larval fish, and fish eggs. Researchers will use samples from this survey to update indices of plankton abundance used in the environmental assessments. 

We conducted plankton sampling around four offshore wind lease areas: 

• Liberty Wind
• Mayflower Wind
• Sunrise Wind
• Bay State Wind

Conductivity, Temperature, and Depth Profiles

The crew deployed an instrument that can measure conductivity, temperature, and depth at all 39 stations on this survey. Seawater conducts electricity. This “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 and measured dissolved inorganic carbon, total alkalinity, pH, and nutrients at eight stations. Increases in dissolved carbon dioxide can increase acidity of the water, which can in turn affect shellfish and other sensitive organisms. The NOAA Ocean Acidification Program funded this work. It was conducted in partnership with NOAA’s Atlantic Oceanographic and Meteorological Laboratory in Miami. 

The crew also collected pteropods from the water column. Researchers examine the condition of the pteropod shells to measure the biological effects of ocean acidification. We conduct pteropod measurements in partnership with the Bermuda Institute of Ocean Science, where the measurement technique was developed by Dr. Amy Maas.

Special Collection Summary

We collaborate with other agencies and institutions, supporting research that enhances core EcoMon sampling. 

Visual Sighting

Two observers were aboard to watch for and record 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. The program is a partnership among scientists from NOAA, the U.S. Fish and Wildlife Service, the Bureau of Ocean Energy Management, and the U.S. Navy.

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. Collaborators include:

• University of Massachusetts Dartmouth
• University of Rhode Island
• Wellesley College