Black Right Whale

Hear how research unfolds at sea in a tiny Zodiac surrounded by creatures half the length of a football field. Playing female whale calls into the water, researcher Susan Parks suddenly finds herself the center of attention of a group of male North Atlantic Right Whales. Will she be able to gather crucial data before a breaching whale crashes down on her boat? Find out by listening to the Podcast of Life on the EOL Learning and Education website, where you can meet the featured scientists, hear extra audio clips and find educational materials.

The North Atlantic right whale (Eubalaena glacialis) is a critically endangered marine mammal (300 to 350 individuals estimated in 2008) in the family Balaenidae, part of the order of cetaceans. The North Atlantic right whale is a baleen whale, meaning that instead of teeth, it has long plates which hang in a row (like the teeth of a comb) from its upper jaws. Baleen plates are strong and flexible; they are made of a protein similar to human fingernails. Baleen plates are broad at the base (gumline) and taper into a fringe which forms a curtain or mat inside the whale's mouth. Baleen whales strain huge volumes of ocean water through their baleen plates to capture food: tons of krill, other zooplankton, crustaceans, and small fish.

North Atlantic Right Whales were hunted for at least 800 years, until they became so rare that it was no longer commercially viable to exploit them. Now numbering only in the hundreds, and showing no signs of recovery, Northern right whales are nearly extinct. Some populations have not shown any significant reproduction, even after becoming protected by law.

Today, the North Atlantic right whale is a rarely observed species, but its name derives from an era when they were more frequently sighted, when they swam slowly, close to shore, thus making them an easy target for whalers. Not only did this swimming behaviour make this whale the right one to hunt, but this whale also floats when dead and yielded vast quantities of valuable oil and baleen.

Despite its bulky size, the North Atlantic right whale is able to perform acrobatic acts such as jumping out of the water, known as breaching, violently slapping the water surface with the tail and/or a pectoral fin. Although the purpose of these behaviours is not fully understood, they may be used in communication. Similarly, the range of low frequency groans, moans and belches that the North Atlantic right whale makes are hypothesised to be used to communicate with other individuals, or signal aggression.

Remarkable for massive size, North Atlantic right whales feed chiefly on minute planktonic prey, including large copepods, the size of a grain of rice; krill, a shrimp-like crustacean; tiny planktonic snails and the drifting larval stages of barnacles and other crustaceans. North Atlantic right whales are skim feeders, meaning they consume prey by swimming forward with mouths open, allowing water to flow into the mouth and out through the baleen. Tiny prey are strained from the water as it becomes caught in the fringed baleen, where it is then dislodged by the tongue and swallowed. Although this whale often feeds at or immediately below the ocean surface, the North Atlantic right whale is also believed to sometimes feed close to the bottom, since it has been seen surfacing after a 10 to 20 minute dive with mud on its head.

After feeding at northern latitudes during the summer, the North Atlantic right whale migrates south for winter. Pregnant females head for the inshore calving grounds, whilst the location of the remaining majority of the population is not known. Wherever they move, this is the season at which mating takes place.

North Atlantic right whale females typically first calve at nine to ten years of age, therafter giving birth to a single young every three years. The gestation period lasts for about one year, and following birth, the mother and her young remain close until the calf is weaned at the age of one. During its first year of life the calf learns the location of critical feeding grounds from its mother, which it will continue to visit for the remainder of its life. The female then takes a third year to replenish her energy stores before breeding again.

The species associated with this page are major players in the pelagic ecosystem of the Stellwagen Bank National Marine Sanctuary. Stellwagen Bank is an undersea gravel and sand deposit stretching between Cape Cod and Cape Ann off the coast of Massachussets. Protected since 1993 as the region’s first National Marine Sanctuary, the bank is known primarily for whale-watching and commercial fishing of cod, lobster, hake, and other species (Eldredge 1993).

Massachusetts Bay, and Stellwagen Bank in particular, show a marked concentration of biodiversity in comparison to the broader coastal North Atlantic. This diversity is supported from the bottom of the food chain. The pattern of currents and bathymetry in the area support high levels of phytoplankton productivity, which in turn support dense populations of schooling fish such as sand lance, herring, and mackerel, all important prey for larger fish, mammals, and seabirds (NOAA 2010). Sightings of many species of whales and seabirds are best predicted by spatial and temporal distribution of prey species (Jiang et al 2007; NOAA 2010), providing support for the theory that the region’s diversity is productivity-driven.

Stellwagen Bank is utilized as a significant migration stopover point for many species of shorebird. Summer visitors include Wilson’s storm-petrel, shearwaters, Arctic terns, and red phalaropes, while winter visitors include black-legged kittiwakes, great cormorants, Atlantic puffins, and razorbills. Various cormorants and gulls, the common murre, and the common eider all form significant breeding colonies in the sanctuary as well (NOAA 2010). The community of locally-breeding birds in particular is adversely affected by human activity. As land use along the shore changes and fishing activity increases, the prevalence of garbage and detritus favors gulls, especially herring and black-backed gulls. As gull survivorship increases, gulls begin to dominate competition for nesting sites, to the detriment of other species (NOAA 2010).

In addition to various other cetaceans and pinnipeds, the world’s only remaining population of North Atlantic right whales summers in the Stellwagen Bank sanctuary. Right whales and other baleen whales feed on the abundant copepods and phytoplankton of the region, while toothed whales, pinnipeds, and belugas feed on fish and cephalopods (NOAA 2010). The greatest direct threats to cetaceans in the sanctuary are entanglement with fishing gear and death by vessel strikes (NOAA 2010), but a growing body of evidence suggests that noise pollution harms marine mammals by masking their acoustic communication and damaging their hearing (Clark et al 2009).

General threats to the ecosystem as a whole include overfishing and environmental contaminants. Fishing pressure in the Gulf of Maine area has three negative effects. First and most obviously, it reduces the abundance of fish species, harming both the fish and all organisms dependent on the fish as food sources. Secondly, human preference for large fish disproportionately damages the resilience of fish populations, as large females produce more abundant, higher quality eggs than small females. Third, by preferentially catching large fish, humans have exerted an intense selective pressure on food fish species for smaller body size. This extreme selective pressure has caused a selective sweep, diminishing the variation in gene pools of many commercial fisheries (NOAA 2010). While the waters of the SBNMS are significantly cleaner than Massachusetts Bay as a whole, elevated levels of PCBs have been measured in cetaceans and seabird eggs (NOAA 2010). Additionally, iron and copper leaching from the contaminated sediments of Boston Harbor occasionally reach the preserve (Li et al 2010).