A Big Climate Warning from One of the Gulf of Maine’s Smallest Marine Creatures

 Given the rate at which the waters in the Gulf of Maine are heating up, Mainers may need to swap out the lobsters on their license plates for squid. New England could issue specialty plates that feature endangered species such as a right whale, cute puffin, or vanishing cod.

For all the escalating climate-related threats to iconic and commercially valuable marine life in the Gulf of Maine, though, scientists say there is one creature we should especially keep our eye on—a barely visible creature that helps those whales, puffins and cod survive: the zooplankton Calanus finmarchicus.

Often likened to a grain of rice, this “copepod”—or microscopic crustacean—is the keystone of the sub-polar food web that makes the Gulf of Maine one of Earth’s richest marine ecosystems. By munching on phytoplankton and microzooplankton invisible to the naked eye, Calanus pack themselves so densely with fatty acids that researchers call them “butterballs” of the sea. Calanus is eaten by many species, including mackerel and cod, right whales, right whales, redfish, haddock, redfish and sand lance. The tiny crustaceans fuel the vast North Atlantic food web, where bigger fish forage on smaller fish until the bigger fish end up in the bellies of seabirds, seals, tuna, other flesh-eating sharks and whales—or on our dinner plates.

David Fields, zooplankton biologist at Bigelow Laboratory, stated that the perfect timing for the Calanus finmarchicus life cycle for fish larvae in the spring and whales in the late summer is one of the top examples of why the Gulf of Maine “is beautifully intertwined and synchronous. It is what has made the ecosystem so productive.”

That very synchronicity, Fields said, also makes Calanus highly vulnerable to the gulf’s warming. This makes these tiny creatures a huge symbol of climate changes. These metaphoric rice grains in the ocean are now slowly disappearing, much like grains in an hourglass.

Dramatic Declines

Already, the Gulf of Maine marks the southern end of this range. Calanus finmarchicusThis is the Atlantic side. Due to record heat, the species is in decline. This could be due to right whales moving northwards in search of food in the Gulf of St. Lawrence. There are also early correlations between a decline in baby lobsters. Although scientists are careful to not say that correlations necessarily mean causation but the decline in Calanus populations coincides the current and projected declines in many fish populations within the gulf.

A major summary paper on climate-driven changes in the Gulf of Maine by 2050 was published last summer. It estimated that current global warming projections will result in a further decline of lobster, cod and pollock, as well as herring, herring, northern shrimps, Acadian redfish, red hake, haddock, pollock and pollock. This finding adds to the 2016 assessment by two dozen scientists at National Oceanic and Atmospheric Administration, which found that more then half of the 80 fish species found on the Northeast U.S. Continental Shelf face a high or very strong probability of their distribution shifting due to climate change.

Despite valiant state and federal efforts to rebuild stocks of many of these species, including redfish and haddock, this is not the case. These shifts will lead to some species becoming less prominent in the Gulf of Maine. However, other species that were more common in the mid-Atlantic such as butterfish, longfin squid and black sea bass will likely be more prevalent. Major effects are already being felt in New England’s fishing communities.

Over the past half century, core populations of lobster have moved northward over 100 miles, giving Maine a temporary boom, while lobstering has fallen in Rhode Island, Connecticut, and Long Island Sound. Last year was the most valuable in the history of Maine’s lobster industry, with 108 million pounds of crustaceans bringing in $725 million in value. However, lobsters are moving so fast towards Canada that there are indications that Maine may have already reached its peak in volume.

The 2021 catch was the 3rd consecutive one of around 100 million pounds. It was still below the record range of 123 to 133 million pounds from 2012 to 2016. Maine’s commissioner of natural resources, Patrick Keliher, said in a press release, “Last year was one for the books and it should be celebrated. But there are many challenges ahead.”

Compound Impacts

The bedeviling thing about the shifts, according to Andy Pershing, director of climate science at Climate Central, and one of the authors of the 2050 summary paper, is that warming is unleashing “compound events” that can spur species’ declines. As a human parallel, Pershing cited Hurricane Ida’s landfall last year in New Orleans. Pershing noted that although some people died in the actual hurricane, many more were affected by the heat wave and lack of power.

The climate-driven warming temperatures have set off a chain reaction that has resulted in the destruction of the oceans. One example is Maine’s northern shrimp, which was a sweet, crawfish-sized regional winter delight. Since 2012’s hottest water records, the shrimp fishing industry has been shut down. A study last summer found that the heat did not cause the crash. It was more likely that shrimp were eaten by longfin squid drawn to warmer waters. The study’s authors said their findings “provide further evidence that changing species interactions will have major impacts as ecosystems face disruptions due to climate change.”

Catastrophic Effects On Seabirds

Last summer, I personally saw how “compound events” create chaos for seabirds at one end of the Calanus food web. I spent several nights on three islands managed by National Audubon’s Seabird Institute and the Maine Coastal Islands National Wildlife Refuge. Although I had been there many times since 1986, I had never seen so many puffin and tern chick carcasses scattered across the landscape. I also didn’t realize the funereal quiet caused by the lack of terns screeching for their chicks.   

The constant double whammy that was heat waves and record rain events led to the death of many chicks. Some chicks starved because the heat drove traditional puffin and tern prey—such as haddock, hake and herring—too far away or too deep for parents to catch. Others died from hypothermia after they couldn’t dry out from the rain. Steve Kress, the 49-year old founder of Project Puffin, said that Eastern Egg Rock, which he had repopulated with that bird, was subject to 54 days of rain events. 32 was the previous record.

New England islands saw record-breaking chick deaths of puffins, terns, and other species. Many puffin chicks that survived the onslaught were so underweight and undersized that researchers called them “micro puffins.” On Eastern Egg Rock, research assistants led me to a spot where an adult tern and its chick appeared to die next to each other. They speculated that the chick died due to hunger, while the adult was trying unsuccessfully to find enough food. “You hear of humans dying of heartbreak,” research assistant Jasmine Eason told me. “This looked like it.”

I heard heartbreak from seabird experts like I have never. Longtime Canadian ecologist and seabird expert Tony Diamond, commenting on what he’s seen on Machias Seal Island, the island in the gulf with the most puffins, said, “Sometimes I’m shocked by the meals the birds are bringing in compared to what we used to see. It used to be a big, fat juvenile herring. Today, so many times, they’re bringing in tiny little fish in their beaks. It’s not nearly enough to sustain them if this keeps up.”

Fellow Canadian researcher Heather Major, Project Puffin ecologist Keenan Yakola, and Gulf of Maine Research Institute (GMRI) scientist Kathy Mills all worry about how the warming creates “mismatches” in when prey bloom and spawn and when predators come and go. For migratory animals, timing is critical. Puffins, for instance, come to Maine’s islands for only about four months of late spring and mid-summer to breed. Right whales get fat in New England, Canada and the Atlantic for their winter calving waters offshore of South Carolina and Georgia.

“A species like the Arctic tern will leave for South America in the fall, but its survival the next year and the survival of its chicks may depend on everything that’s happening in Maine while it is away,” Yakola said.

Record Heat

The fate of terns, whales and puffins after their winter migrations will depend on how much human activity is done to reduce global warming. Gulf of Maine Research Institute recently reported that last fall was the hottest on record in the Gulf. The average sea surface temperatures in October, which used to hover around 60 degrees Fahrenheit, were almost 5 degrees warmer. Even November, a month when temperatures have dropped to the high 40s, was still warm.

The historical average was 4 degrees Fahrenheit warmer than the sea surface temperatures. Since 2010, six of the warmest summers for sea surface temperatures in Maine have been logged. The gulf set a single-day sea surface record temperature of almost 70 degrees in 2020. The primary reason is the warm Gulf Stream expanding its presence while cold currents coming down form Labrador are losing their strength.

“We’re getting to levels that are really exceptional,” Mills said. “We’re already running ahead of climate models. There’s always going to be some year-to-year variability, but the warming has become a persistent pattern where variability doesn’t get us back to ‘normal,’” she added.

For cold-water sea creatures, such a 4-to 6-degree sea temperature difference is like stepping out of an air-conditioned house into the scorching Arizona summer heat. The big question is can humans keep nature’s “air conditioner” running in New England.

Don Lyons, director of conservation at National Audubon’s Seabird Institute, home of Project Puffin, said he remains hopeful that the Gulf of Maine can inspire action on climate change because there’s been so much investment in preserving so many species of animals and so much habitat. These waters are a concentrated area of historic conservation successes, such as the restoration of puffins and the rebounding fish stocks. They also include the creation of the Maine Coastal Islands National Wildlife Refuge in 1972 and the Northeast Canyons and Seamounts National Marine Monument in 2016.

The overall investment and vigilance to preserve the gifts of the Gulf continues to pay dividends. Over the past decade, there have been plenty of cooler summers with record heat to keep puffin numbers at record levels. At most, one bird is 32-years old. The population of some cousins to the puffin, the razorbills, and murres, is increasing. “We’re not going to avoid all impacts,” Lyons said. “But I think it’s possible for us to bend the curve.”

To bend the course of events ultimately means curbing fossil fuels that cause climate change’s heat-trapping greenhouse gases. It means that we cannot just “ooh and ahh” at whales and puffins; we need to look out for the health of creatures like Calanus finmarchicus. In the paper on the gulf at 2050, Pershing, Mills, Diamond and 10 other co-authors said this zooplankton is the “signature invertebrate animal of the North Atlantic subpolar ecosystem.”

Without it, there’s no telling how many more whales we will see blowing at the surface, how many puffin will be bringing fat juvenile haddock for their chicks, or whether there will be a fat Maine lobster on your plate. In 2016, a campaign of schoolchildren led to the official designation of the lobster as the state crustacean for Maine. Maybe now is the time to launch a campaign to to Calanus finmarchicus the official plankton of New England, before they—and the lobsters they help sustain—are gone. 

This Article previously appeared on the Union of Concerned Scientists’ blog The Equation.

Derrick Z. Jackson, Inside Climate News’ consulting editor for justice, is an award-winning journalist and author. He was the 2021 winner for Excellence in Opinion Writing in the Scripps Howard Awards for his coverage of systemic racism in the United States’ response to Covid-19 for the Union of Concerned Scientists (UCS) and Grist. His book “The Puffin Plan,” that chronicled the restoration of puffins to the coast of Maine, co-written with Steve Kress, won the 2021 first-place Gold Award in Teen Nonfiction in the Independent Book Publishers Association Benjamin Franklin Awards. He was a 2001 Pulitzer finalist “for his perceptive, versatile columns on such subjects as politics, education and race” for the Boston Globe. Jackson is a ten-time National Association of Black Journalists contest winner, most recently in 2017 for an essay about Muhammad Ali. Jackson is a native of Milwaukee (Wisconsin) and a 1976 University of Wisconsin Milwaukee graduate. He is a recipient of three honorary degrees from the Massachusetts College of Liberal Arts and Salem State University, as well as the Episcopal Divinity School.