Monday, July 24th, 2017

Climate change affects Maine market

Krysteana Scribner | The Free Press

Posted on April 22, 2017 in News
By USM Free Press

Krysteana Scribner | The Free Press

By: Heather Roberts, Staff Writer

The early arrival of spring may be a relief to the people of Portland, but for scientists, early spring means a rapidly changing ecosystem. According to the National Weather Service, in 2016, the average temperature in Portland was 48.4 degrees Fahrenheit, which was as high as 2012.

The Gulf of Maine Research Institute’s Andrew Pershing and USM’s Karen Wilson observed that the change in Maine’s temperature affected Maine’s lobster, cod and herring populations, which have influenced the Maine market. Both scientists noted the change in Maine’s temperature in 2012 and its effect on life.

“In 2012, we had temperatures throughout the year where we were almost three degrees Celsius above normal,” said Pershing. “So that would work out to almost five degrees Fahrenheit above normal on any given day of the year.”

The change in temperature affected river herring spawning. Wilson said that, in 2012, at a spawning site, herring were aware of the temperature change because they arrived four weeks early.

According to Pershing, the lobster in 2012 mated a month early. The increase of lobster lowered the market price. Although lobstermen caught a lot of product, they made less money compared to 2011.

Between 2004 and 2013, the Maine cod market also suffered. Pershing said that the temperature increase reduced the cod population before fisheries could adjust their quotas. He added that the fisheries later realized the quotas were set too high.

Warming temperatures may decrease cod food sources such as river herring, especially during spawning. These herring spawn in May and leave between July and October. Wilson reasoned that despite the changing climate, river herring are highly adaptive, but because of droughts the fish can’t get to spawning sites or out to the ocean.

“Last summer we had a drought starting in July that lasted to October. There was not enough water going over the dam,” Wilson said. “People kept reporting that the adults were still in the lake. They stayed in the lake and it wasn’t until October when we had the first rains that the fish started to leave.”

Temperature change may have an impact on river herring travel. Wilson added that warmer temperatures may bring the river herring’s sister species, the blue herring, north. Other southern species may also travel to Maine waters.  According to Pershing, Humboldt squid and striped bass are likely arrivals.

“In 2016, we had a year as warm as 2012,” Pershing said. “In many ways, the landing and fisheries played out very similarly to what they did in 2012.”

Pershing explained that, because of what occurred in 2012, markets adapted to the overproduction of lobster. By learning and adapting to Maine’s temperature change, fisheries can avoid overfishing, high quotas and economic setbacks.  

In Portland on Saturday, April 22nd, an estimated 1,000 people gathered downtown for the March for Science in response to Trump’s cuts to the EPA and National Parks, as well as to show support for scientific research surrounding climate change. Other marches took place around the country.