BAR HARBOR — Scientists this winter will revive a long-running survey of plankton in the Gulf of Maine. Plankton, drifting microscopic sea organisms, are food for endangered North American right whales and other marine species.
The Gulf of Maine plankton survey was originally performed from 1961–2017. It is returning under a new agreement between the National Oceanic and Atmospheric Administration’s (NOAA) Northeast Fisheries Science Center, the Marine Biological Association in Plymouth, England, and the Massachusetts-based Woods Hole Oceanographic Institution.
“Many marine species are shifting their distributions as ocean waters warm,” said Chris Melrose, a research oceanographer at the Northeast Fisheries Science Center’s laboratory in Narragansett, R.I. “Because plankton are an important food source for many species, including the endangered North Atlantic right whale, knowing about changes in the plankton helps us to understand other changes we see in the ecosystem.”
Melrose, who is NOAA representative on the agreement, said continuing the survey “is essential to understanding the impact of climate change to marine ecosystems.”
The survey will use a continuous plankton recorder (CPR), a sampling device that is roughly 3 feet long, towed by so-called “ships of opportunity,” such as merchant vessels. The Marine Biological Association manages merchant vessel-based plankton surveys around the world. Under the agreement, the association will continue the Gulf of Maine survey through 2024.
While sampling, the recorder stays at a depth of roughly 33 feet and collects plankton over long distances. The samples are later analyzed in a lab. The technique has not changed since 1958, meaning data can be easily compared to previous years.
“The value of sampling in an area accumulates each subsequent year, building a dataset of evidence and insight that we can use to understand recent changes in the marine ecosystem of the Gulf of Maine,” said David Johns, head of the CPR Survey at the Marine Biological Association. “We can compare our new dataset with the historical time series and start to put these changes into context in a warming world.”
The CPR Survey this year included more than 7 million nautical miles of tows. The monthly plankton sampling effort was focused in the Northeast and Northwest Atlantic and on the northwest European shelf.
Funding for the Gulf of Maine survey effort is through the NOAA Cooperative Institute for the North Atlantic Region, hosted by the Woods Hole Oceanographic Institution.
Data from the 2014 to 2017 tows in the Gulf of Maine were recently made publicly available through funding from the LenFest Ocean Program.
The resumed Gulf of Maine survey will add to plankton samples collected on two other Northwest Atlantic CPR Survey routes. The first route runs from Nova Scotia to Cape May, N.J. The second extends from Iceland to Newfoundland.
Data also is collected in other regional sampling efforts, including an ecosystem monitoring program conducted numerous times during the year along the Northeast U.S. Continental Shelf.
Data from the Gulf of Maine survey have been analyzed by the Gulf of Maine Research Institute.
“The Gulf of Maine is changing quickly and the CPR is our best tool for seeing the impact on the base of the food web,” said Andy Pershing, chief scientific officer at the Gulf of Maine Research Institute. “This view is essential for understanding how climate change will impact commercial species like cod, herring and haddock, and protected species like right whales.”