Rockfish coral (Photo courtesy Northeast Underwater Research, Technology and Education Center at the University of Connecticut)
Rockfish coral (Photo courtesy Northeast Underwater Research, Technology and Education Center at the University of Connecticut)

Most people when they hear the word “coral” think of shallow, turquoise water and colorful reefs populated by bright tropical fish. Now think again. In the cold and often dark Gulf of Maine, spectacular cold-water coral formations, some of which may be hundreds if not thousands of years old, are just now being mapped and explored. 

Most cold-water corals lie in the very deep submarine canyons and seamounts along the edge of the continental shelf. Yet they also occur in deep areas of the Gulf that are closer to shore, such as Jordan Basin. Cold-water corals typically are soft corals with flexible skeletons, unlike the coral species that build tropical reefs. Fishermen have long been familiar with taller coral outcroppings, which they called “trees,” on Georges Bank and other shallow-water areas in the Gulf. 

Since 2013 scientists funded through NOAA’s Deep Sea Coral Research and Technology Program have been conducting research cruises in the Gulf of Maine using remotely controlled underwater vehicles and multibeam sonar to identify cold-water coral communities. This year during a ten-day research cruise, scientists from the University of Maine, the Northeast Fisheries Science Center, and the Northeast Underwater Research, Technology and Education Center at the University of Connecticut looked at three areas: Outer Schoodic Ridge, the Mount Desert Rock area and the Georges Basin region. 

A site on Outer Schoodic Ridge showed dense coral and sponges along the bottom and on the steep vertical walls. Scientists also observed a tremendous number of haddock moving through the coral. In previous years large schools of pollock and silver hake had been seen in the same place. In the Mount Desert Rock area scientists found two coral walls brimming with red tree coral, fan coral and multiple species of sponge. As one researcher said, the sight was “spectacular.”

At the base of the slope stretching from Georges Bank into Georges Basin things were very different. The area showed the effects of fishing activity, primarily trawling; some areas were scraped clean of all life. Steep vertical rock outcrops, like those in the northern Gulf that support dense coral gardens, were bare from the seafloor to six meters in height. What corals the researchers did find were tucked into crevices and cracks along the walls, places somewhat safe from trawler gear.

 

In a report to the New England Fisheries Management Council (NEFMC) in December 2014, scientists involved in previous years’ Gulf of Maine coral research emphasized the role that deep-sea corals play in providing habitat for all sorts of marine species. Pandalid shrimp, amphipods, and schools of krill hang out among the corals; these species are food for larger, commercially valuable fish. Redfish use coral for shelter. Atlantic cod, cusk, pollock, and silver hake have been seen searching for and catching their prey amid the coral colonies.

The fragility of deep-sea corals and their value to commercial species of fish led the Mid-Atlantic Fishery Management Council (responsible for fisheries management from New York to North Carolina) in June to propose restricting fishing activities over an area of deep ocean bottom stretching from Long Island to Virginia. If approved by the National Marine Fisheries Service, the council’s proposal would create the largest area protected from bottom fishing in U.S. Atlantic waters, about the size of Maryland, Delaware and New Jersey combined.

In New England, the NEFMC also is tackling the question of how to best protect these coral formations, many of which have not yet been mapped. Allowing fishing gear to trash a form of life so beautiful and rare, which also provides a hunting ground for the creatures that we like to eat, makes little sense. On the other hand, the Gulf of Maine is now, and has been for centuries, a working sea. It is not a park. Men and women go where the fish are and use all sorts of fishing equipment to efficiently and economically harvest the species that we want. Balancing these two facts will be difficult.

 To do so the New England Council is developing something called an omnibus amendment that will apply to all fisheries management plans operating in the Gulf of Maine. The amendment will change each plan by designating specific “coral management areas.” Within those areas, certain types of fishing are likely to be prohibited. “The fact that we found these spectacular walls of corals after 40-plus years of research with submersible vehicles illustrates how much more we need to understand about the Gulf ecosystem,” said Peter Auster, of the University of Connecticut, who has participated in each of the recent research cruises. “If these corals are destroyed, they are not coming back in any ecologically significant period of time.”