Why Marine Life Is So Diverse in the Gulf of Maine

The Gulf of Maine is one of the most important marine habitats in the world and home to a wealth of marine life, from giant blue whales to microscopic plankton. Overview The Gulf of Maine is a semi-enclosed sea that covers 36,000 square miles of ocean and runs along 7,500 miles of coastline, from  Nova Scotia,  Canada,  to  Cape Cod,  Massachusetts. The Gulf is bordered by three New England states  (Massachusetts, New Hampshire, and Maine) and two Canadian provinces (New Brunswick and Nova Scotia). Water depths in the Gulf of Maine range from zero feet to several hundred feet. The deepest spot is 1,200 feet and is found in Georges Basin. The Gulf of Maine has many dramatic underwater features, which were carved out by glaciers  10,000 to 20,000 years ago. History The Gulf of Maine was once dry land covered by the Laurentide Ice Sheet, which advanced from Canada and covered much of New England and the Gulf of Maine about 20,000 years ago. At that time, the sea level was about 300 to 400 feet below its current level. The weight of the ice sheet depressed the Earths crust, and as the glacier retreated, the area that is now the Gulf of Maine filled in with seawater. Types of Habitat The Gulf of Maine is home to a variety of different habitats. They include: Sandy banks (such as Stellwagen Bank and Georges Bank)Rocky ledges (such as Jeffreys Ledge)Deep  channels (such as the Northeast Channel and Great South Channel)Deep basins with water depths over 600 feet (such as the Jordan, Wilkinson and Georges Basins)Coastal areas near the shore, whose bottoms are composed of rocks, boulders, gravel, and sand Tides The Gulf of Maine has some of the greatest tide ranges in the world. In the southern Gulf of Maine, including the area around Cape Cod, the range between high tide and low tide may be as low as four feet. But the Bay of Fundy, which borders the northern Gulf of Maine, has the highest tides in the world. Here, the range between low and high tide can be as great as 50 feet. Marine Life The Gulf of Maine supports over 3,000 species of marine life. They include: About 20 species of whales and dolphinsFish, including Atlantic cod, bluefin tuna, ocean sunfish, basking sharks, thresher sharks, mako sharks haddock, and flounderMarine invertebrates such as lobsters, crabs, sea stars, brittle stars, scallops, oysters, and musselsMarine algae, such as kelp, sea lettuce, wrack, and Irish mossPlankton, which provide food for many larger marine species that live in the Gulf of Maine Scientists believe the Gulf is probably home to many more unidentified species, including small worms and microscopic bacteria. Information about individual marine species is available from the states Department of Marine Resources. Human Activity The Gulf of Maine is an important area, both historically and today, for commercial and recreational fishing. It is also popular for recreational activities such as boating, wildlife watching (such as whale watching), and scuba diving (although the waters can be chilly). Threats to the Gulf of Maine include  overfishing, habitat loss, and coastal development.