The Eubalaena genus encompasses the three distinct species of right whales, large baleen whales known for their immense size and slow movements. These marine mammals are recognized by their unique physical characteristics and are a significant focus for conservation efforts worldwide. Their survival is challenged by human activities, making their study and protection important.
Distinctive Physical Features
Right whales possess a robust, stocky body that is dark gray or black. They lack a dorsal fin on their backs, giving them a smooth, continuous outline when viewed from above. Their V-shaped blow, or spout, produced when they exhale through two widely separated blowholes, allows scientists to identify them from a distance.
Their most striking physical identifiers are callosities, roughened patches of skin on their heads. These patches are dark but appear white or yellowish due to colonies of tiny crustaceans that inhabit them. The arrangement and pattern of these callosities function like a fingerprint for scientists to track and identify individual whales throughout their lives. Callosities are present from birth and continue to develop as the whale matures.
Species, Habitat, and Diet
The Eubalaena genus includes three recognized species: the North Atlantic right whale (Eubalaena glacialis), the North Pacific right whale (Eubalaena japonica), and the Southern right whale (Eubalaena australis). Each species occupies distinct oceanic regions, with warm equatorial waters acting as a natural barrier preventing mixing between northern and southern populations. All three species undertake seasonal migrations between warmer calving grounds and cooler feeding areas.
The North Atlantic right whale inhabits the western North Atlantic Ocean, migrating between feeding grounds off New England and Canada and calving areas off the southeastern United States. The North Pacific right whale is found from Japan across to Alaska, including the Bering Sea and Gulf of Alaska. Southern right whales are distributed throughout the Southern Ocean, moving between sub-Antarctic feeding areas and temperate coastal waters of South America, Africa, and Australia for breeding.
Right whales are filter feeders, consuming tiny marine organisms. Their diet consists mainly of copepods, which are small crustaceans, along with krill and other small invertebrates. They employ “skim feeding,” swimming slowly near the surface with their mouths open. This allows water to flow through their baleen plates, comb-like structures inside their mouths, filtering out microscopic prey. An adult right whale can consume up to 2,000 pounds (900 kilograms) of food daily.
Conservation Status and Threats
The name “right whale” originated from whalers who considered them the “right” whales to hunt due to several characteristics. These whales are slow-moving, tend to stay close to coastal areas, and possess a high blubber content, which made them float after being killed. This combination of traits made them an easy and profitable target for commercial whaling, leading to a severe decline in their populations over centuries.
Despite international protection from whaling since 1935, right whale populations have struggled to recover, with the North Atlantic right whale listed as critically endangered. The species faces two primary threats that impede its recovery. Entanglement in commercial fishing gear, such as lobster and crab pot lines, is a significant cause of injury and mortality. Over 85 percent of North Atlantic right whales have experienced entanglement at least once, which can lead to severe injuries, infections, and even death as whales are forced to drag heavy gear for extended periods.
Collisions with ships, also known as vessel strikes, represent another major threat. Right whale habitats and migration routes overlap with busy shipping lanes, increasing their vulnerability to being hit by vessels. These collisions can result in broken bones, severe internal injuries, or fatal cuts from propellers. The speed of a vessel during a collision directly correlates with the likelihood of serious injury or death for the whale.