Did eclipse cause salmon net pens to break apart?
Scientists are debunking the claim by the owner of a fish farm in near Washington's San Juans that Monday's eclipse affected the tides, causing the net pens to fail.
Net pens holding farm-raised Atlantic salmon between Guemes and Cypress islands broke apart. The company, Canadian based Cooke Aquaculture, said at least 4,000 to 5,000 fish were released into surrounding waters, causing the Washington Department of Fish and Wildlife to encourage fishing enthusiasts to catch them.
Cooke Aquaculture said in a press release, “Exceptionally high tides and currents coinciding with this week’s solar eclipse caused damage to a salmon farm that has been in operation near Cypress Island for approximately 30 years.”
Can we blame it on the eclipse? News reports quoting scientists on both sides of the border are skeptical of that claim, finding it hard to believe the eclipse has anything to do with it.
“It wasn’t the fact that it was an eclipse,” said Parker MacCready, a University of Washington oceanographer who is an expert in coastal tides. “I don’t know what happened with the net pen, but I would say this 'spring tide' that happens around the time of the eclipse was not different than any other.”
A spring tide has nothing to do with the seasons on the calendar but has everything to do with the strong tides that accompany a new moon.
As for this spring tide?
“In fact, it might have been a little weaker than other ones recently or during the winter," MacCready said.
In other words, it was no record breaker. MacCready says a spring tide on June 23 was stronger.
According to the Washington Department of Fish and Wildlife, the net pens began to break apart at 4 p.m. of Saturday. That was two days before the eclipse. The tide was not small. As measured from the highest to the lowest that day, it was just over 9.5 feet. That was up from nine feet on Friday, but below the 9.8 feet reached on Sunday, the day after the break was reported.
What about eclipse day on Monday? The total swing from lowest to highest was actually going down to 9.72 feet and continued to decline on Tuesday to 9.29 feet.
But Washington’s San Juan Islands are considered the most complex mix of tides and currents on the U.S. West Coast, said U.W. oceanographer Hal Mofjeld, who is also retired from the National Oceanic and Atmospheric Administration.
Currents that day were running as fast as 3.5 knots, though they were running closer to two knots Saturday afternoon. Mofjeld says part of the problem with currents in the San Juans are strong eddies closer in to shore where the pens were located.