Over the past thousand years, the Gulf of Maine went through a period of cooling. But according to a new study using data from the shells of quahogs, a type of clam with a long lifespan and a shell with incremental growth each year, researchers found that global warming has entirely reversed this trend. Scientists were able to estimate water temperatures and ocean salinity by analyzing isotopes stored in the shells.

The data revealed the long-term cooling of the Gulf of Maine resulted from volcanic activity until the late 1800s when the trend began to reverse. Over a span of 1000 years, the Gulf warmed faster during the 20th century than it had during any other 100-year period.

Why This Matters

All sectors of Maine’s economy -- energy, agriculture, forestry, fishing, and tourism -- will be impacted by climate change. While the state’s forests promise to be a valuable carbon sink, the Gulf of Maine is a special ecosystem for fish and bird migration, plankton, and the North American right whale, but its waters are warming faster than 99% of the world’s oceans. Maine is beginning to lose its subarctic characteristics and could see between 1.1 and 1.8 feet of sea level rise by 2050. Meanwhile, ocean acidification will affect aquaculture projects, especially those involving marine organisms that produce calcium carbonate to build shells, such as oysters, scallops, clams, mussels, and sea urchins.

As Maine’s Climate Council put it, “Warming winters reduce snowpack and change snowmelt, river, and lake ice-out dates, causing ripple effects through Maine’s biodiversity, agriculture, inland lakes and streams, and winter-based recreation.”

Lobsters In Peril

Warming waters in the Gulf of Maine also spell trouble for Maine’s iconic lobster industry. Increasingly warming ocean water is killing the zooplankton population, which lobster larvae need to eat to grow. As a result, the number of baby lobsters have sharply declined. A study from a few years ago estimated that the gulf lobster population could plummet by up to 62% by 2050.

This could have a major ripple effect on Maine’s economy. Lobster is the state’s most significant fishery. Last year’s catch was valued at $730 million, the highest price on record and $300 million more than 2020’s valuation. This comprised 82% of the $890 million made with last year’s catches.

Lobsters are not the only beloved food on climate change’s chopping block. Pizza, popcorn, salmon, even sriracha, could become scarce following the decline of key crops like tomatoes, corn, and chili peppers, and a decline in fish and shellfish populations. One California restaurateur, Tony Montagnaro, suggested that pizza was “may be running the risk of becoming a seasonal food,” if tomato crops cannot survive in the face of extreme heat.