July 8 2022 โ Scientists have known the Gulf of Maine is warming rapidly, but new research suggests itโs also getting saltier, more acidic and increasingly stratified โ raising concerns for its fish stocks.
The dramatic shifts in the gulfโs biochemistry are raising questions about the future of a region that has historically produced some of the worldโs richest fish stocks โ from cod to lobsters โ and has built billion-dollar industries around them.
โWe found that primary productivity, the rate at which the phytoplankton is fixing carbon in the ocean, has dropped to about a third of what it was in the early 2000s,โ Barney Balch, a biological oceanographer and senior researcher at the Bigelow Laboratory for Ocean Sciences, told UPI. โThat really raised alarm bells with us.โ
According to Balch, decreases in primary productivity โ the carbon fixing โ may affect life in the gulf from phytoplankton all the way up the food chain, including fish that humans eat.
For more than 20 years, Balch and his research partners have been helping NASA calibrate and validate ocean surface temperature data collected by the agencyโs polar-orbit satellites.
Many researchers have pointed to the Gulf of Maine as one of the worldโs most rapidly warming bodies of water, but Balchโs paper, published this month in the Journal of Geophysical Research: Biogeosciences, is one of first to showcase the full scope of the gulfโs regime change.
While itโs not yet clear how these changes will impact the regionโs ecosystems, data collected by Balchโs team suggest the base of the marine food web in the gulf is in the midst of a transformation.
Over the last 30 years, warming has mostly proven a boon to lobsters in the Gulf of Maine, especially in places, like the Penobscot Bay and the Bay of Fundy, that were historically on the chillier side of a lobsterโs comfort zone.
And though Balch isnโt privy to the data being collected by Wahle and his research partners, he says itโs not a stretch to hypothesize that declines in diatoms, a primary source of nutrients for copepods, are likely to have ripple effects up the food chain โ ripple effects that will ultimately impact the lobsters and some number of other fisheries.