It’s probably not surprising that the two largest oil spills in American history are the Deepwater Horizon disaster in the Gulf Coast and the Exxon Valdez in Alaska. The third largest, however, hit a little closer to home.
Over the years, thousands of ships have gone down off the coast of Cape Cod and the Islands. But on December 15, 1976, when the Argo Merchant ran aground in the shoals 25 miles south of Nantucket, it was in a class all by itself.
“The Argo Merchant was such a large ship, it had such a huge cargo of dangerous material aboard, and that’s what heightened our fear,” said WGBH News’ Bob Seay, who covered the story in ‘76 for a small station in Orleans.
The cargo was 7.7 million gallons of No. 6 oil — a thick, sludgy fuel oil used to heat New England homes. The fear was that cargo escaping, and making its way ashore and into some of the world’s most productive fisheries nearby.
“So, it sat out there on one of the sandbars south of Nantucket, literally kind of balanced on one of those sandbars, swaying back and forth,” Seay said.
For days. Pounded by heavy seas. The crew was rescued. Attempts were made to buttress the ship, to lighten its load, and to tow it out of the shoals.
“It was a daily, almost hourly watch, and we knew eventually that the ship was not going to survive,” Seay said.
On December 21, the Argo Merchant split in two, and released all 7 million-plus gallons of its viscous cargo into the waters off Nantucket. At the time, it was the largest maritime oil spill in American history.
“Volume is not the greatest indicator of impact, you know, there are other things,” said Chris Reddy, who studies oil spills for the Woods Hole Oceanographic Institution. “Oil spills are like buying a house: Its location, location, location.”
Location, in this case, was in their favor. The spill happened far from shore. And the westerly winds pushed most of the oil slick out into the vast open Atlantic, though some did hurt and kill birds and other sea life in the immediate area. No. 6 oil tends to float, and in the fierce churn of the vast ocean, it breaks into smaller and smaller pieces and — over time — degrades biologically. Location also provided a surprising silver lining.
“That was in an area where there was a capacity of scientific people to respond,” Reddy said.
And respond they did. Existing models about how oil travels via ocean current were tested — and improved. Studies were rushed onto the scene that led to a better understanding of how sediment moves along the ocean floor. The science done completely changed the way we respond to — and recover from — oil spills moving forward.
“The Argo Merchant, for us, for the Office of Response and Restoration and for NOAA is a seminal spill,” said Steve Lehman of the National Oceanographic Atmospheric Administration.
In ’76 NOAA was a fairly new endeavor. On the scene, they served as a conduit between the science and recovery efforts.
“The relationship between NOAA and the U.S. Coast Guard worked out so well that we were added as part of their response team and have been ever since,” Lehman said.
Between its relatively minor impact — and the leaps taken in science — the Argo spill is about as close as an ecological disaster can get to being a “feel good” story. But reflecting back on those tense weeks on Cape Cod, Seay says he can’t help but marvel at just how easily it could have gone the other way.
“If the winds had been coming from the south, it would have been an entirely different story,” he said. “Nantucket would have been covered in oil, the Cape might have been affected, certainly the fisheries, but it did not. So in a way it was a Christmas blessing.”
The Argo Merchant oil spill started when the 641-foot oil tanker ran aground off Nantucket, 38 years ago this week.
If you have a forgotten tale from Massachusetts history, or if there is something you’re just plain curious about, email Edgar at curiositydesk@wgbh.org.
