By Lynda Clancy of the Penobscot Bay Pilot
PenBayPilot.com
ROCKPORT — A longterm warming trend of the Gulf of Maine waters is underway, scientists agree. And on top of that, a more recent rate of change has dramatically increased.
Data collected at multiple buoys between the shore and Browns Bank deliver data confirming warmer waters; yet, what will happen to the fish, and the fishing industry, remains hypothetical as scientists look at the entire Atlantic Ocean, its currents and ecology. In the meantime, Maine fishermen watch for emerging trends and cope with change.
And, they provide the anecdotal evidence of how marine life may be adjusting to rising water temperatures. They help document patterns, such as where lobsters thrive, and the size of the shrimp and cod catches. They spot where whales and other sea mammals visit, and when fish spawn. Together, the fishermen and scientists are watching and recording, and talking, as they witness a shift of Atlantic cod and other fish towards the cooler northeasterly waters, with some even disappearing.
Sessions held at the Feb. 28-March 2 Maine Fishermen’s Forum touched on ocean acidification, advances in lobster science, ocean renewable energy and closed scallop areas. Data gathered by marine scientists, who, over the past 20 years, have steadily increased their monitoring and analysis of the Gulf of Maine and the Atlantic Ocean, also was featured at the forum.
The National Oceanic and Atmospheric Administration, the U.S. Army Corps of Engineers, and some universities have stationed monitoring buoys and sensors on the gulf and near Massachusetts Bay and Long Island Sound, testing temperatures, wave action, wind speed, salinity. Their sensors take measurements at the ocean bottom, mid-column and at the water’s surface.
Tom Shyka of the Northeastern Regional Association of Coastal and Ocean Observing System (NERACOOS), a collaboration of scientists and organizations who synthesize and interpret a vast collection of data from the sentinel monitoring. was a panelist at the Saturday seminar, “Changing Ocean: What Changes Are We Observing in the Gulf of Maine and What Does It Mean for the Ecosystem?”
Shyka cited several studies conducted over the past several years, including that of the American Meteorological Society that tracked a long term water warming thrend from 1880 to 2000. While that study noted a spike in water temperature during the 1940s, followed by a rapid cooldown in the 1950s, there has been a steady rate of warming over the past seven years with a much high rate of change in addition to the long term trend.
In 2011, the average water temperature began to increase at the end of the year, and throughout 2012, the buoys were recording readings “well above the average temperature,” he said. While calculating the data involves closely watching the anomolies, “the trend of anomolies suggest the water temperature is warming,” he said.
For instance, a buoy located in Penobscot Bay recorded in 2012 a mean water temperature in March of 39.2 degrees Fahrenheit. The mean water temperature for 2001 to 2013, however, in March, is 35.85 Fahrenheit.
Panelist Jeffrey Runge, a scientist at the Gulf of Maine Research Center, referenced other studies recording increases in water temperature. He described the 100-year warming trend of annual increases of 0.01 degrees centigrade. But since 2004, that annual rate of change has increased 10 times the 100-year trend, he said, from 0.1 to 0.3 centigrade per year. In rough translation, that describes the mean temperature of gulf waters increasing over the past eight years by approximately four degrees Fahrenheit.
He attributes the increases to precipitation and the subsequent increase of fresh water river discharge into the Gulf of Maine.
And, he said, “the transport dynamics has changed.”
The transport dynamics include the change of currents from waters flowing in and out of the Gulf of Maine through the Northeast Channel and the eastern Scoatian Shelf that originates from the Gulf of St. Lawrence and Labrador. There is now an increase of fresher coastal inflow.
Further south of the Gulf of Maine, warming waters have already triggered more drastic results. The warm summer of 2012 caused the entire water column in Long Island Sound to heat up so much that the nuclear reactor at Millstone Nuclear Power Station in Waterford, Conn., was forced to shutdown. The water temperature, according to NERACOOS, was “above the permitted temperature allowed for cooling.”
Those warm waters also are attributed to encouraging an abnormally large red bloom in Long Island Sound.
As the scientists watch the Gulf in this warming trend they are concerned that increased water temperatures could affect the biological clocks of marine species, which spawn at specific times of the year based on environmental cues like water temperature.
“Anyone who spends time on the water has seen changes in less than two years,” said Steve Train, panel moderator, and captain of the Wild Irish Rose, encouraging his colleagues to pay attention to what they witness out on the water.
Lynda Clancy is co-editorial director of the Penobscot Bay Pilot.