WASHINGTON — Ocean surface temperatures around the world were the warmest on record for the month of June, according to federal scientists, though they caution that one month doesn't necessarily imply global warming.
The warmer temperatures do confirm that an ocean phenomenon known as El Nino is building in the Pacific Ocean.
Some scientists think that the rising temperatures hint at broader changes, perhaps resulting from global climate change. Environmentalists and fishermen are wary of what it may mean.
"It's really kind of disturbing," said Zeke Grader, the executive director of the Pacific Coast Federation of Fishermen's Associations, based in San Francisco. "What we've seen right offshore here is a real variation in temperature. But we don't know what to expect in the future."
So far, the year has been among the warmest on record for ocean temperatures, ranking sixth based on January through June. The June temperature averaged 62.56 degrees Fahrenheit; the 20th-century average was 61.5 degrees. The National Oceanic and Atmospheric Administration has been keeping the records since 1880.
"The high ocean temperatures can threaten coral reefs, provide more energy to hurricanes, cause thermal expansion, which would raise sea level and inundate coasts, force the relocation of some aquatic species and thus impact fisheries," said Ahira Sanchez-Lugo, a NOAA climate scientist.
The hottest spots were the north Pacific south of Alaska, along the U.S. West Coast and the Atlantic Ocean off New England. Overall, the Pacific was the warmest. The measurements were taken for every 5 degrees of latitude, however, and an overall temperature for each ocean wasn't calculated, said Deke Arndt, a climate scientist with NOAA in Ashville, N.C.
"Individually, no single month can be attributed to long-term global warming," Arndt said, though he added that this June marked the 33rd consecutive June with a temperature above the 20th-century average, which may provide an indication of global warming.
In addition to having the warmest waters, this June saw the second warmest combined ocean and land temperature on record, 61.02 degrees, which was more than a degree above the 20th-century average of 59.9.
Though some climatologists dismiss the June heat as an anomaly, others say it's part of a traditional El Nino pattern. Occurring roughly every three to eight years, El Nino is a warming of water in the eastern Pacific Ocean, which can disrupt usual weather patterns. During an El Nino year, the Southwest United States tends to be wetter, the Northwest drier and there's an increased chance of severe weather, such as hurricanes, in the Southern United States.
"Current conditions and trends, as well as the majority of dynamic climate models, are suggesting that (El Nino) will indeed occur," said Karsten Shein, another climate scientist with NOAA.
Grader said fishermen were worried about their catches, and he, for one, thinks that it isn't just El Nino that's causing the higher ocean temperatures.
"Colder water fish will go north," he said. "It'll affect phytoplankton and krill production. You'll see salmon getting smaller."
Other fishermen aren't as concerned.
"We've fished El Ninos before," said Larry Collins, 52, a commercial fisherman based at Fishermen's Wharf in San Francisco. "There's good and bad things about El Ninos for the California coast. Nature will throw you a curveball."
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