June 8, 2022 — The Gulf of Maine is growing increasingly warm and salty, due to ocean currents pushing warm water into the gulf from the Northwest Atlantic, according to a new NASA-funded study. These temperature and salinity changes have led to a substantial decrease in the productivity of phytoplankton that serve as the basis of the marine food web. Specifically, phytoplankton are about 65% less productive in the Gulf of Maine than they were two decades ago, scientists at Bigelow Laboratory for Ocean Sciences in East Boothbay, Maine, report in new results published today.
The Gulf of Maine helps fuel New England’s marine ecosystems and economy. Like plants on land, phytoplankton absorb carbon dioxide from the atmosphere and use photosynthesis to grow, and then become a food source for other organisms. Disruptions to their productivity can lead to adverse effects on the region’s fisheries and the communities that depend on them.
“Phytoplankton are at the base of the marine food web on which all of life in the ocean depends, so it’s incredibly [significant] that its productivity has decreased,” says William Balch, the Bigelow Laboratory scientist who led the study. “A drop [of] 65% will undoubtedly have an effect on the carbon flowing through the marine food web, through phytoplankton-eating zooplankton and up to fish and apex predators.”