One of the favorite feeding grounds for an endangered whale is, well, an endangered ledge.
A Fertile Forest
Cashes Ledge, an underwater mountain range located 80 miles east of Cape Ann in the Gulf of Maine, teems with wildlife. As with many seamounts, the Ledge’s steep ridges and deep basins, as well as its kelp forests, create an underwater landscape ideal for marine animals to hide, hunt, and spawn.
Because of this abundant ecology, Cashes Ledge is looked upon with increasing desire by commercial fishing interests who want to be able to bring in bottom trawlers to get at the diverse populations of finfish who feed and breed there: fish like cod, haddock, hake, and halibut.
But humans aren’t the only ones who want to fish at Cashes Ledge: the richness of the indigenous ecosystem attracts ocean predators like migrating bluefin tuna, sharks, and yes, whales—all of whom depend on ecosystem of the Ledge for food.
With its abundant upwellings of plankton, Cashes Ledge is an important feeding stop for endangered humpback whales during their seasonal migration in the spring and early summer, and for even more critically endangered North Atlantic right whales, who feed at the Ledge during the summer and fall. The Ledge also attracts smaller, swifter minke whales, who dive in the slicks of calm water between the internal waves, as well as harbor porpoises.
Right whales use their long black baleen plates, as long as a person is tall, to strain tiny zooplankton and krill out of the water. And there is plenty of plankton to be had at Cashes Ledge! The steep topography and stratified water column around Ammen Rock, the highest peak in the Cashes range, generates an oceanographic phenomenon known as internal waves, which bring plankton-rich waters into a highly dynamic circulation. The force of the internal waves pushes the warm water from the upper levels of the water column against the peaks and slopes of the ledge, driving it down to mix with colder depths, delivering a rich supply of plankton to the bottom. The warm water rises back to the upper photic zone where it is pushed along the ledge and forced downward again. This process, which happens as many as 20 times a day, results in the regular circulation of nutrient-rich water within the water column, and an area of high productivity and energy.
A Wayfaring Whale
For all their size and might, there are fewer than 500 North Atlantic right whales alive on Earth today. Right whales are sometimes referred to as “urban whales,” as their migratory pathways carry them along coastlines busy with human commercial activity. Because they sift their food slowly at the water’s surface, they are vulnerable to injury or death from ship strike and entanglement in fishing nets.
Calving female right whales migrate south along the Atlantic coast of North America to bear their young in warmer southern waters, but in general, rights love to move about the Gulf of Maine in a regular pattern, looking for where the food supply is best. “Cashes Ledge is one of the stopping-off places for North Atlantic right whales and humpbacks, both endangered,” says Stormy Mayo, Senior Scientist and director of right whale habitat studies at the Provincetown Center for Coastal Studies. “Cashes Ledge is notoriously rich and doubtless plays in important role in the rich processes of the Gulf of Maine.”
Whales have always been inextricably linked to their food: find one, and you find the other. Like all other animals, they go where the food is. In Moby-Dick, the crew of the Pequod locates right whales through the presence of “brit” — yellow swarms of copepods on the water.
An Interdependent Symphony
With fewer than 500 individuals left on the planet, every North Atlantic right whale is essential to the survival of the species. Protecting whales means preserving the ecosystems in which they can be nourished and healthy to survive the hazards of migration along highly-trafficked waterways.
One important way to protect animals is to keep the habitat that supports them intact and thriving. Which is why CLF is asking fisheries managers to permanently protect this special place. You can help by signing their petition.
Defending Cashes Ledge from trawling will benefit not only the gigantic right whales, but also a host of interdependent species, including cod, bluefin tuna, and other iconic “New Englanders.” CLF seeks to make the current industrial fishing restrictions on Cashes Ledge permanent, to ensure that this unique and vital habitat is fully restored and thriving to support generations of whales to come.
Laura Marjorie Miller writes about travel, ocean conservation, Yoga, magic, myth, fairy tales, photography, and other soulful subjects. She is a regular columnist at elephantjournal, a writer at UMass Amherst, and a travel correspondent for the Boston Globe. Her writing has appeared in Parabola and she has features forthcoming in Yankee Magazine and Seven Miles of Steel Thistles. She is based in Massachusetts, where she lives with a cat named Huck.