Spring 2025 Northeast Ecosystem Monitoring Survey Completed

Ecosystem Monitoring Survey Mission

The Northeast Fisheries Science Center’s Ecosystem Monitoring Cruise, or EcoMon, helps understand and predict changes in the Northeast shelf ecosystem throughout the year. These changes influence the productivity of fisheries. EcoMon’s comprehensive shelf-wide ecosystem data (hydrography, ocean chemistry, plankton) and analyses support everything from fisheries stock assessments to research on the North Atlantic right whale.

EcoMon maintains a record of ocean measurements going back more than 40 years. The survey typically collects data in:

• Mid-Atlantic Bight
• Southern New England
• Georges Bank
• Gulf of Maine

Its ocean measurements help understand and predict changes in the shelf ecosystem that affect fisheries productivity and management.

Dates and Location

The spring 2025 Ecosystem Monitoring Survey sailed from May 27–June 6 out of Newport, Rhode Island, aboard the NOAA Ship Henry B. Bigelow. The survey was shortened to accommodate the HabCam survey. Scientists prioritized sampling in areas important to the Atlantic mackerel egg index, data that is crucial for stock assessment.

Spring Ecosystem Monitoring Survey Overview

Despite the shortened schedule, scientists were able to sample 86 out of 167 planned stations, completing about 51 percent of the planned research activities. We sampled most of the stations offshore of Southern Massachusetts to New Jersey. Scientists sampled about half of the planned stations between New Jersey and North Carolina and in the Gulf of Maine. They dropped the majority of the offshore stations on Georges Bank and in Canadian waters.

Core Sampling on the Ecosystem Monitoring Survey

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Core sampling data from EcoMon Surveys help us understand changes in:

• Distribution and abundance of zooplankton and larval fish
• Water temperature
• Salinity
• Ocean Chemistry

Scientists conducted 86 bongo net tows during the survey to study the foundation of the marine food web—fish larvae, crab larvae, copepods, and small jellyfish. Scientists use the larval fish and egg samples to learn more about fish stock spawning and help estimate stock abundance. Seven of the stations where they collected plankton samples were within wind energy development areas. This will help scientists better understand how marine development affects plankton abundance. In addition, they collected 13 water samples for environmental DNA analysis in tandem with bongo net samples.

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The science team also collected physical oceanography data by deploying a conductivity, temperature, and depth instrument at 111 stations.

Scientists from NOAA Fisheries mounted a dynamic above-water radiance and irradiance collector hyperspectral radiometer on the forward mast of the NOAA Ship Bigelow. They used this tool to collect optical measurements for satellite remote sensing calibration.

Ocean Chemistry

The science team collected water samples for carbon analysis at 23 stations to support ongoing research on marine carbon cycling and ocean acidification. Additionally, they collected pteropod (planktonic snail) samples at 19 stations. They will use these to study the effects of ocean carbonate chemistry on shell-building organisms at the base of the food web, which help sustain fisheries.

Marine Mammals, Birds, and Sea Turtle Observations

Trained observers spent a total of 51.5 hours documenting marine mammal, seabird, and sea turtle sightings over 45 visual transects. These observations are used to track migration patterns and determine how animals find food and habitat during their journeys.

They documented oceanic birds including Wilson’s storm petrel, Parasitic jaegers and marine mammals including dolphins and fin, humpback, and minke whales. Jameson Chace, a Salve Regina University professor who specializes in ornithology, participated in the survey.

Special Collections and Partners

The Ecosystem Monitoring Survey is collaborative—in addition to NOAA scientists, partners aboard the spring survey included scientists from five other institutions:

• Woods Hole Oceanographic Institution
• University of Rhode Island
• University of Connecticut
• College of the Holy Cross
• Salve Regina University

During the spring survey, three optical instruments counted phytoplankton for 1,750 nautical miles. Scientists from the University of Rhode Island and Woods Hole Oceanographic Institution deployed Imaging FlowCytobots. Similar to automated underwater microscopes, these capture high resolution images of phytoplankton and measure the chlorophyll fluorescence and light scattering associated with each image. The data they collect helps scientists study changes in phytoplankton communities over time.

University of Rhode Island scientists, with NASA funding, deployed a flow cytometer to study phytoplankton smaller than those measured by the Imaging Flowcytobot. They also deployed a radiometer to observe how phytoplankton change the optical properties of seawater. This information will help improve the use of satellite-based ocean color measurements to study phytoplankton from space.

Scientists from the University of Connecticut collected water samples to study monomethylmercury, a neurotoxin that bioaccumulates in marine food webs, in phytoplankton.

The physical and chemical conditions that EcoMon measures help scientists understand:

• Ecosystem productivity
• Fish spawning
• Larval recruitment
• Species distribution

Data Collection and Use

You can view the Ecosystem Monitoring Survey’s long term plankton abundance and distribution data, conductivity, temperature, and depth data, and ocean chemistry data.