Southern Right Whales

The southern right whale, Eubalaena australis, is considered a National Natural Monument in Argentina. As long as
50 feet and weighing up to 60 tons, their presence is impressive as they materialize from the Patagonia gloom.

Right whales are the most endangered of all the great whales. At the turn of the 20th century, estimates indicate fewer than 2,000 individuals remained worldwide. Considered the "right whales" to kill on a hunt, hence their name, these whales were an easy target because they were slow swimmers, and their thick blubber caused them to float when they died. Their oil and baleen fetched colossal prices for various human uses, and for that they nearly became extinct.

Northern populations were hit far harder than those in the more remote regions in the southern oceans. The southern right whale, Eubalaena australis, does not cross the equator and is a different species from its northern cousins. While both the North Atlantic and North Pacific right whales are still considered endangered, with populations numbering only in the hundreds, southern right whales have been making a comeback.

Thanks in large part to conservation efforts beginning in 1935, southern right whales have been registering a population growth of approximately 7 percent annually. In 1984 Argentina declared the right whale a National Natural Monument, making it the first cetacean to receive this status.

At first underwater glance, southern right whales appear somewhat bedraggled. Lacking the majestic look of the humpback or the smooth aerodynamic shape of the blue whale, these giant mammals have their own inimitable appearance. Their blunt, oversized heads with an abundance of comblike baleen make up nearly one-third of their stout, 50-foot stature. Right whales can weigh up to 60 tons and have one of the longest lifespans of any cetacean, living up to 100 years. They have no dorsal fin but lumber slowly and effortlessly through murky water. They also have two blows that form a signature V-shaped spout. Areas of their heads are covered with thickened patches of skin called callosities, the pattern of which is unique to each individual and thus helps with identification. Soon after whales are born, these areas become covered with cyamid whale lice that feed on the whales' skin.

Southern right whales migrate twice each year: once to their feeding grounds near the Antarctic Convergence, where they feast on zooplankton, and then to the warmer sheltered bays of New Zealand, Brazil, Chile, Peru, Uruguay, Argentina, Australia and South Africa, to give birth, raise their calves, socialize and ultimately mate. Mothers and calves often seek the protection of shallow water, sometimes near the shoreline, possibly to avoid harassment by males trying to mate.

When it comes to mating, right whales are polygamous. Females become sexually mature between the ages of 8 and 10 years and may have as many as eight different mates. For their part, the males sport the largest testes of any animal, weighing more than a ton. The males have a large cavity in which their genitals remain while they swim or rest. Size does matter here, and the whale with the largest testes — producing the most sperm — is the one most likely to impregnate the female.

Males are known to be relatively gentle and do not compete aggressively with one another during courtship. From June through October, males charm females by persistently nudging and rubbing up against them in attempted mating. When the female is not interested, she will roll onto her back, but insistent males generally will endeavor to roll her back over again.

Right whales give birth every three to four years. After an 11- to 12-month gestation period, a single calf is born, weighing two to three tons. Calves grow quickly because their mothers' milk is extremely rich in fat.

White right whales typically are not albino but rather are young whales that darken with age.

Less than 5 percent of right whale calves are born white. These are not albino whales; the condition is only temporary, and their skin darkens as they age. The exhilaration of photographing a white baby whale underwater is an unforgettable experience. The white whales have little camouflage and dramatic appearances, making them prospective targets for predation.

The mothers judiciously lead their calves away from danger, which is why underwater images of them are exceptionally rare. With proper guidance from a ranger (who is always present when diving with these whales in Argentina), once the mother becomes tranquil, realizing that the few divers in the water pose no inherent risk to her precious baby, extraordinary encounters can happen. Approaching any wild animal up close, however, always presents a certain degree of risk. Even when following all the rules the situation can change in an instant. Not only is the mother protective of her newborn, a three-ton baby may also be protective of its mother. A head butt is enough to let everyone know the session is over and it's time to move on.

Right whales are curious and good natured, often casually approaching the boat close enough to be touched. They drift along with their heads above the surface as if to investigate the new interloper. Tired from journeying thousands of miles to the calm, warmer waters, the mothers spend much of their time relaxing on the surface and allowing their newborn calves to peacefully feed and explore their new surroundings.

Right whales often drift along with their heads just out of the water and are known to approach boats in a friendly manner.

In many locations, however, seagulls pose a threat to these young calves as well as very old whales, pestering them by landing on the whales' backs to peck off meals of dead skin but frequently taking chunks of flesh in the process. Adult whales use the practice of spyhopping to avoid the constant assault, lifting only their hard, knobby heads from the water, just far enough to breathe. Some nursing mothers have adopted a "galleon" position, wherein they arch their backs underwater to expose only their heads and flukes at the surface. Lacking the ability to protect themselves and unable to arch their small backs, newborn calves are vulnerable to the gulls' relentless harassment. The calves' wounds can become so large and badly infected that they can be life threatening.

While some mothers and calves have learned to surface at an oblique angle to breathe, which allows them to keep their backs underwater, performing these evasive maneuvers takes away energy that should be spent nursing and resting at a time when food is scarce. The stress and depleted energy could affect their growth and development as well as their chances of survival. The mortality rate of southern right whale calves has increased significantly since 2003, and some researchers speculate that gull harassment could be a major factor in the fatalities.

These whales are planktivorous, feeding mostly on plankton and krill.
Right whales are plankton feeders, and their diet consists primarily of krill. Ocean acidification threatens this all-important link in the food chain, and the whales' destiny is inherently tied to it. Warming oceans have given rise to vast concentrations of the algae Pseudo-nitzschia, which produces the neurotoxin domoic acid. Some scientists believe this neurotoxin contributes to significant mortality of southern right whales less than three months old, affecting population growth. Like all cetaceans, southern right whales also face the serious threat of collision with ships and entanglement with fishing gear.

The southern right whale is now the right whale to embrace — with the eye, the binoculars and the lens. Harpoons from a bygone era now reside in museums such as the New Bedford Whaling Museum in Massachusetts, and the legends have slipped into the pages of maritime history. Once hunted to near extinction, the right whale has been granted renewed worldwide citizenship and safe passage. Perhaps one day all whales might enjoy the same status.
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Learn more in this video, Southern Right Whales of Argentina.

© Alert Diver — Q2 Spring 2017