2021 Northeast Summer Ecosystem Monitoring Cruise Completed

September 03, 2021

The 2021 Northeast summer ecosystem monitoring survey aboard NOAA Ship Pisces completed sampling at about 85 percent of their planned stations.

Feature Story |

New England/Mid-Atlantic

A white circular frame with 12 gray bottles is suspended over the ocean water from an A-frame on the side of the ship. The image is taken from above the A-frame. It is daytime in good weather. Two crew in hard hats stand on the deck near the rail, beneath the sampling gear.

Researchers returned to sea for the second ecosystem monitoring (EcoMon) cruise of 2021. Scientists and crew aboard the NOAA Ship Pisces sampled at 149 stations. They achieved near-complete coverage of the survey area, from north of Delaware Bay through the Gulf of Maine.

Four people on deck at the rail of a ship photographed from the pier as the ship pulls away. It is daytime. They are wearing short-sleeved shirts, hard hats, and cloth face masks. — The plankton sampling team of Audy Peoples, Harvey Walsh, Quentin Nichols, and Nicole Morse (A.I.S.) prepare to depart on the NOAA Ship Pisces for the summer 2021 ecosystem monitoring cruise off the Northeastern United States. Credit: NOAA Fisheries/Jerry Prezioso

Fewer days were available for the cruise than originally planned. The scientific crew dropped all stations south of Delaware Bay at the beginning of the cruise to allow for full coverage in the north. Favorable weather and sea conditions during the entire survey allowed for supplemental stations to be added on the end of the cruise. Sample stations were added adjacent to Nantucket Shoals, near foraging North Atlantic right whales and in and around wind energy lease areas.

Zooplankton are tiny animals and very young stages of some animals that will grow larger. Samples of zooplankton provide information about the food chain supporting fisheries and marine mammals. Scientists use larval fish and egg samples to learn more about fish stock spawning and help estimate stock abundance. Measurements of physical and chemical conditions like temperature and salinity help us describe ecosystem productivity, spawning, larval recruitment, fish condition, and species distributions.

Together, the core measurements conducted by our EcoMon cruises help researchers understand and predict changes in the Northeast shelf ecosystem and its fisheries. Researchers are scheduled to sail on the next EcoMon survey in October aboard the Pisces.

Chart showing the area of planned operations off the East Coast, station locations and the type of sampling done at each during the 2021 Northeast summer ecosystem monitoring cruise. — Survey area and stations for the 2021 Northeast summer ecosystem monitoring cruise. In all, 149 stations were completed, with 28 planned stations dropped in the south and 3 in the northeast. Seawater measurements were made at all stations, plankton samples were taken at 133 stations, and chemistry samples and eDNA samples were taken at 35 stations. Credit: NOAA Fisheries

Core Sampling Summary

Plankton Collection

Core EcoMon sampling includes “bongo” net tows to collect zooplankton, larval fish, and fish eggs. These fine-mesh nets are attached to side-by-side steel rings, resembling bongo drums when deployed. During this survey, bongo net tows were conducted at 133 different stations. Samples from this survey will be used to update an index of plankton forage for the 2022 State of the Ecosystem report.

The contents of a plankton net tow with all the water drained away. The samples are spread on a flat, light colored surface. There are 6 silvery larval fish, a mass of pink material, and small, transparent jelly-like balls. — A plankton sample collected in the Gulf of Maine shows several communities, larval fish in the upper left, copepods in the center, and salps (or pelagic tunicates)— the clear jelly balls at the bottom of the image. Credit: NOAA Fisheries/Harvey Walsh

Conductivity, Temperature, and Depth Profiles

Seawater conducts electricity. The level of “conductivity” varies by depth and other oceanographic factors and is used to estimate the salinity of seawater. At all 149 stations, the crew deployed an instrument that can measure conductivity, temperature, and depth. 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 28 stations. Increases in dissolved carbon dioxide can increase acidity of the water, which can in turn affect shellfish and other organisms that are particularly sensitive to the acidity of ocean water.

Special Collection Summary

More than 200 black and white images of different kinds of phytoplankton displayed together in a collage. — Phytoplankton from the surface seawater intake are collected and imaged with the imaging flow cytobot. Seawater is pumped through the instrument, and it takes images of plankton in that water, displaying and storing the data on a laptop computer. Credit: NOAA Fisheries/Harvey Walsh

Our EcoMon program collaborates with other agencies and institutions to support research that enhances core EcoMon sampling. While COVID-19 mitigation protocols limited external participation on this survey, the summer 2021 EcoMon cruise included sampling for several ongoing projects with external partners.

Protected Species

Two observers were aboard to watch for and record data on seabirds, marine mammals, and sea turtles encountered along the cruise track. This is part of the Atlantic Marine Assessment Program for Protected Species, 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

An imaging flow cytobot was deployed aboard the ship and used to image and count phytoplankton cells continuously from surface waters during the ship’s transit. This work is part of a National Science Foundation project led by Woods Hole Oceanographic Institution with collaborators from the University of Massachusetts Dartmouth, the University of Rhode Island, Wellesley College, and NOAA Fisheries.

eDNA

Environmental DNA sampling was conducted to test the technique as a way to monitor finfish by detecting genetic material they shed in the water column.