October 23, 2023 — Over the last 20 years, the Gulf Stream has warmed faster than the global oceans and shifted closer to the shore, increasing the likelihood that the tropical ocean current could suddenly impact U.S. coastal fisheries, according to a new study published this month.
Physical oceanographers Robert Todd and Alice Ren from the Woods Hole Oceanographic Institution found the Gulf Stream has warmed 2 degrees Fahrenheit and moved 6 miles closer to the eastern continental shelf since 2001, according to findings published in Nature Climate Change.
The Gulf of Maine is most influenced by the Labrador Current, which brings colder water from the north. The oscillating Gulf Stream generally passes 100 miles south of the Gulf of Maine’s southern border, but warm-water breakaways from it can still increase Gulf of Maine temperatures for months at a time.
Scientists say it is too early to know for sure, but increasingly warm core rings that break away closer to shore could have a significant impact on environmental conditions, and marine wildlife, within the Gulf of Maine, according to Todd, the study’s lead author.
“These rings have a very sharp temperature contrast,” Todd said. “They come in and very suddenly you have very warm water in the spot where you had cold water before. It’s temporary, for the life of the ring, but it’s a long enough period of time that the fish, the shellfish, they care.”
This study focused on the general Gulf Stream that hugs the U.S. coast from Florida up to Cape Cod, before it flows east toward Europe, but Todd notes that other researchers have found the number of warm core rings formed by the Gulf Stream has roughly doubled since 2000.