From funding the American Revolution into luring fishermen to the area, cod has been a crucial to the history, economy, and culture of New England.  In the past three decades fisheries and government officials have noticed a significant decline in Cod populations, and have attempted to prevent further declines.  However, a recent study headed by Andrew Pershing of Gulf of Maine Research Institute, proves that climate change and fisheries mismanagement are causes of this severe decrease in stocks.  This study used data from Cape Cod all the way up to Canadian, Nova Scotia and was published in Science Journal as the first scientific report to confirm that climate change is responsible for less cod.  In order to truly grasp the cause and effects of warming seas on cod, one must understand their lifestyle and the oceanography of the Gulf of Maine.  The Gulf of Maine is in the Atlantic

Gulf Stream Current

Gulf Stream Current

encompassing lower parts of Canada down to Massachusetts, and is home to an ecosystem of marine fish and mammals that have adapted to very cold ocean temperatures.  A prime fishing ground located 60 miles offshore, Georges Bank, is renowned by fisherman for producing massive numbers of cod; however, cod is scarce there as well.  The Gulf Stream current is part of the deep-ocean current system known as the Global Conveyor Belt.  Warm water, devoid of many nutrients, is carried along the Gulf Stream from Florida up to the Northeast where it is cooled by cold, dense water brought down from the poles, thus creating a frigid ocean climate that is teeming with nutrients.  

In the Gulf of Maine the ocean temperatures have risen 4 degrees Fahrenheit, which is a sharper temperature increase than what was experienced in 99% of other major bodies of water worldwide. The study found that the cooling of the Gulf Stream now occurs further North due to changes in other major ocean currents in Atlantic and Pacific waters. Cod thrive surrounded by cold water because it is both nutrient and Oxygen rich, but warming seas are pushing their populations to the breaking point.  Fisheries officials estimate that cod populations in New England have decreased by 90% in the past three decades.  The scientific study proves that an increase in warm water in the Gulf of Maine has not only decreased the number of new Cod but also decreased chances of fish Fig1_SST-Gulf-of-Mainesurviving into adulthood – a deadly combination for a struggling species. Climate change has crafted a perfect storm for the cod as their food sources have moved Northward following the cool water, while predator populations, such as marine mammals, have bloomed making cod’s centuries old home much less hospitable,  

What is being done to save the cod? NOAA scientists have tracked cod populations for years in an effort to understand how the population changes and how to limit fisherman in order to preserve the species.  However, this new study contradicts fisheries management decisions by claiming that, “The government has been overestimating the cod population and underestimating their mortality rates.”  The quotas set by the government have allowed overfishing because of the miscalculation of cod in the Gulf of Maine, as current stocks are only 3% of what can sustain a healthy population.  John Bullard, regional NOAA administrator, says that he is not surprised at these findings and that, “management decisions made five years ago were wrong,” because faulty models were all they had to guide them.  Instead of purely surveying cod, as NOAA has been, the study suggest that researchers take a more “ecosystem-based” approach.  The study’s leader believes that federal officials need to take into account temperature, climate forecasts, food availability, and reproductive rates, “to provide a more realistic picture of the potential size of fish stocks.”

Now that it has become clear that previous models developed by NOAA government officials falsely represent the actual number of cod in New England, scientists and fisheries management must come together to create a better management plan for this key species.  Quotas have been continuously lowered over the years, but scientists believe that this is not enough to revive the populations.  Scientists believe that they need to increase the number of areas that are completely off-limits to fishing because it will allow larval fish survival, reproduction, and an overall safe haven for populations to eat, grow, and thrive.  The major obstacle officials and scientists face is the approval of new, stricter regulations by the New England Fishery Management Council.  The executive director of the council agrees that they need to change their management tactics in order to cope with the threat of climate change and increased declines in fish stocks.  However, many fisherman on the council do not believe that cod populations are in jeopardy, instead they say, “the study is entirely based upon the false premise that cod are actually at a low level.”  The extensive study proves that compared to historical numbers, cod populations are very low.  Fisherman may say this because cod are easier to catch as their numbers drop because it forces them to congregate near popular spawning areas, as a natural response.  Fisherman need to support an increase in the number of off-limits areas because without it the cod population is at risk to die out completely leaving them jobless.

Kelp Forest and Cod at Cashes Ledge; 70-miles off the coast of Maine

Cod fish

Cod is incredibly important to the people of the Northeast, which is why they should support further protections of cod because it is possibly the only way populations will continue to survive.  Overfishing, in part allowed by false government cod calculations has greatly decreased cod.  In addition, the warming of the Gulf Stream and Gulf of Maine has forced prey to move Northward, and contributed to increased stress and mortality rates.  Climate change coupled with overfishing has spelled disaster for this popular fish species, however if we act now the iconic cod can continue swimming and prosper once again in the waters of New England.

 

Sources:  https://www.bostonglobe.com/metro/2015/10/29/climate-change-seen-contributing-collapse-cod-stocks-off-new-england/WIMPUHnYWBwNBDJ0QpcqWO/story.html