Gulf of Maine

Marine Fisheries Impacted in the Gulf of Maine


There is evidence that the fisheries industry in the Gulf of Maine is changing which has become a challenge to the livelihood of fisherman. According to the Gulf of Maine Research institute the water temperatures in the area have increased by 0.26°C every year since 2004.  As waters warm species travel north from their typical range to find preferential water temperatures.

The focus has generally been on cod, but this applies to all groundfish such as haddock, pollock and flounder which are typically managed together.  It is believed that the cod are going to deeper offshore waters, but according to scientist John Annala, it is a bit of a mystery as to where they have gone as they aren’t showing up in surveys, including ones done in Canada.  Fish from the Mid-Atlantic region have started moving north into the Gulf of Maine.  The species that are being found most often include butterfish, long fin squid, black sea bass and summer flounder.

While it seems that the fisheries industry would be alright as they could just switch to fishing different species, it is more complicated than that.  Different types of fish require different types of equipment to catch, which can be very costly.  Also, management practices are not in place for species that have not typically been found in the area.  There has also been an increase in lobster to the area, which would seem beneficial, but there has been an increase in lobsters that are shedding which sell for much less than the hard shell version.

Ecological issues can arise when new species move into an unusual territory.  The new species may compete with the historical species for food and habitat and there may be a lack of predators in the new range to keep the new species in check.  While some species may change their range, it is possible that they begin to change their habits to account for the change in temperature.  Examples include feeding at different times of day or shifting diets to account for loss of previous diet staples. It is possible that the whole food web of an area is altered and if equilibrium isn’t reached the ecosystem could crash.  Shell fishermen have also noticed an invasive green crab that has moved north with the warming waters and has become an unchecked predator. Phytoplankton are also affected by temperature.  In the ‘90s there was an influx of cold water that caused the phytoplankton to thrive, leading to increased numbers of zooplankton and herring (Jacobson).As the water warms, phytoplankton, the base level of the food web, could be disrupted causing instability in subsequent levels.  As the stability of the ecosystem decreases due to changing climate and species composition, it becomes more likely that it will not recover in the face of rapid change (Jacobson).

Thank You to OCEAN Researcher Nicole Smith

For more information on climate change in Maine and how it will disrupt not only the marine fisheries, but biodiversity and economics throughout the entire state go to and read the University of Maine document “Maine’s Climate Future: An Initial Assessment.”