• Taylor Davis

Marine Species Migration in the Gulf of Maine

The Gulf of Maine is very well known for its lobster industry, but how much longer will this important commerce, as well as many others, be available? The drastic effects of climate change have caused marine species to begin migrating at an alarming rate. As U.S. waters warm, it is forecast that many fish species will migrate hundreds of miles northward. With the Gulf of Maine being one of the fastest warming ocean areas in the world,[1] it is expected that by 2100 mainstays of the fishing industry, including cod, will be well out of reach for U.S. fisherman. [1] A study by Malin Pinsky, researcher at Rutgers University, has shown that 686 North American fish species are forecast to have a much larger migration, in search of colder water temperatures, than expected.[1] So, what does this mean for these affected species, as well as the Gulf’s vitally important fishing industry?

The U.S. Fish and Wildlife Service has recently become aware of how climate change is going to drastically change the future of Maine’s wildlife. Bob Houston, a biologist and a GIS specialist in the Gulf of Maine Program identifies 168 species of plants, fish, birds, and other wildlife in Maine that could experience wide range shifts in population.[4] Even though climate change is affecting all species across the globe, ocean species are migrating ten times faster than land species. This is due to the oceans taking in the excess heat from the land.[4] Climate change has warmed the oceans of the globe to the point where native fish species have been forced to migrate north from their now uninhabitable environments. They have been found migrating northward in the search of colder ocean temperatures. According to Nick Bradford, researcher at the National Environmental Education Foundation,[6] “more than 80% of the earth’s marine life is migrating to different places and changing their breeding and feeding patterns due to warming waters.” Not all species have been found to be migrating at the same time, however, which causes a disruptive shift in the foodweb.

Although finding colder waters is the main cause of mass migration, it is not the only cause; some species base their migration patterns around their prey.[6] When these patterns are disrupted, predator-prey relationships are altered, mass strandings are increased, starvation is increased, and poor reproductive success is increased. In the Gulf of Maine, Atlantic cod (Gadus morhua) prey on a specific species of zooplankton, when they first hatch; however, higher sea surface temperatures have caused a massive shift of zooplankton to cooler waters. Lower reproductive success has been found among the populations of Atlantic cod where the zooplankton has already shifted, this will make it very difficult for the Gulf of Maine cod industry to continue in the future.[6]

Modified from original graphs by Pershing et al., 2015

As waters warm, they become less hospitable to the cold-loving species such as cod and other groundfish that were the backbone of the coastal New England economy for hundreds of years,” NOAA research suggests that there will be an abundant decline in groundfish in the upcoming decade.[5] Commercial fishing is one of Maine’s largest industries, with Maine fisherman bringing in nearly $570 million worth of seafood in 2017. Of that, $434 million was contributed by the lobster industry, which landings had fallen 15% from 2016.[5] Although there is a decline in lobster, the soft-shell clam industry is at particular risk with the spread of the invasive green crab species (Carcinus maenas). The green crab has been in Maine for over a century but has only started to become an issue with warming waters causing them to be able to multiply at an immense rate.[5] These crabs are found to be the largest predator to clams. In 2017, Maine reported their smallest commercial clam harvest since 1930.[5] With cod looking to decline 90% by 2100, lobster population looking to shift another 200 miles north to Canadian waters, Atlantic sea scallops looking to shift 430 miles north, and clams already declining, it is no doubt that the Gulf of Maine’s fishing industry will go at a rapid decline unless they are able to adapt to current and future situations. With current species migrating out of the Gulf of Maine, and new species