THE RETURN OF THE RIGHT WHAL ES

Forest and Bird, Issue 267, 1 February 1993, Page 10

THE RETURN OF THE RIGHT WHAL

ES

Tim Higham

In June last year an Airforce surveillance flight over the New Zealand subantarctic recorded one of the largest congregations of southern right whales seen anywhere in the world this century. TIM HIGHAM reports on the fall and rise of one of the world’s rarest whales.

ROM THE ANDOVER plane above the Auckland Islands observers spotted 50 whales in the harbour of Port Ross. Others were seen in the island’s eastern bays and fiords — a total of 70 including seven calves. Unusually clear and calm conditions made the historic flight possible, the only mid-winter census since coast watchers occupied Auckland Island during World War II and the Hardwicke whaling and farming settlement of 1849-52. Only

several whales were recorded during these periods of earlier occupation. Two months later, in August, I flew over the Auckland Islands in conditions more typical of the subantarctic winter. Gale-force westerlies caused the Airforce Orion to shudder violently as it banked to low altitude around Enderby Island. Despite uncertain footing in the crowded cockpit and squalls whipping the sea surface we managed to make out the distinctive broad backs of numerous night whales still in Port Ross. Thanks to the

Royal New Zealand Airforce we were now able to confirm that breeding activity in this population lasted at least two months. HE RIGHT WHALE belongs to that group of huge filter-feeders known as baleen whales. The baleens number 11 species and include the largest animal of all, the blue whale. There are now two species known as right whales, one for each hemisphere; the northern right whale, Eubalaena glacialis, and the southern right whale, Eubalaena australis. Raght whales also form several distinct populations within each hemisphere. The north-east Atlantic and north-east Pacific stocks are on the verge of extinction, being represented by little more than a hundred individuals in each. Stocks in the north-west Atlantic, north-west Pacific, south-west Australia and south-east Australia/New Zealand regions are estimated at several hundred animals each. South Africa and Argentine Patagonia are currently thought to support the world’s largest stocks, in excess of 500 animals. Classified as vulnerable, the world population is estimated at only about three percent of its pre-harvest level. The right whale was so named because it swam slowly and close to shore, and was easily harpooned from row boats based at shore stations. Whales also floated when dead and yielded large amounts of premium quality oil and baleen. Raght whales were the first whales to

be hunted commercially, by the Basques of northern Spain, as early as the 12th century. By the 16th century the population was so depleted that whaling fleets set out to exploit new stocks around Newfoundland and Labrador, and, in the 17th century, around Spitsbergen and Greenland. With the collapse of each stock the whalers looked to new grounds — off South Africa, Japan, Brazil, Peru and Chile, Australia and New Zealand — to keep Europe’s whale-oil-powered street lamps burning. In south-east Australian and New Zealand waters at least 26,000 right whales were killed, mainly in the 1830s and 40s. So complete was the destruction of this region’s population that the first documented 20th century sighting of a right whale off the Australian coast was not until 1955. Now, protected from commercial whaling since the 1930s, this great whale is starting to make a comeback, particularly the southern species. Off Patagonia’s Valdez Peninsula 900 individuals have been identified from photographs taken during aerial surveys over 20 years, nearly 500 of which have been identified in more than one season. Such data has been used to estimate that the population is increasing at a rate of 7.6 percent a year and that the average calving interval is 3.6 years. Aerial surveys have also been made off the South African and Western Australian coasts for over a decade and populations there show similar trends.

Southern right whale

ight whales together with the related pygmy right whale (also found in New Zealand waters) and bowhead whale (found only in the Arctic) have deeply curved jawlines and long slender baleen plates. Right whales swim slowly with their mouths open, sieving concentrated pockets of zooplankton on or under the sea surface, which they scrape off the baleen plates with their tongues.

Average adult length Average weight Colour Distribution Numbers 15 metres 50-56 tonnes black; some individuals with large white patches all southern oceans from about 20°S to 55°S estimated 3,000

The whales’ wake

HE FIRST WHALING ship listed as calling into a New Zealand port was the William and Ann in 1791. Lured by the reports of whales by early explorers, British and American vessels continued to ply the country’s off-shore waters until the 1830s. Their main target was the sperm whale; the quarry was rendered down at sea, and Maori settlements used as a source of provisions and extra hands. In 1829 the first shore-based stations were established in Cook Strait and in Fiordland’s Preservation Inlet to target the winter and spring migration of right whales close to shore. By 1844 over 80 such stations had been established, dotted along the eastern coastline from East Cape to Foveaux Strait. Some operated only for a short period. In addition, foreign ships, known as bay whalers, anchored in coastal waters and com-

peted with the shore bases for whales. Even incomplete whaling records show 26,000 right whales were killed in south-east Australian and New Zealand waters, three quarters of them in the decade 1835-44. During this period the region supplied a major proportion — probably about one third — of the world’s total right whale catches. Look-outs were established on high ground near the bases and the tell-tale, V-shaped blow of night whales could be observed up to eight kilometres off-shore. Clinker-built row boats were dispatched carrying about eight men, an oarsman in the stern and a harpooner at the bow. Cows entering bays to calve were quickly exterminated. Those in groups migrating northwards ran the gauntlet of rival stations along each section of coast. Once secured by harpoon the

whales were towed to shore, their blubber cut away and rendered down in try-pots, and the oil separated and stored in wooden barrels. A stench of rotting offal and blubber scraps, and greasy smoke from the try-pot fires which coated buildings and trees, characterised each whaling base. But the smell of whale was the smell of money. Like today’s petroleum industry, the end products provided lighting, heating and lubrication. A secondary product — the horny, keratin plates of the whales’ baleen — was used to make chair seats, corsets and buggy whips. In 1840 over twice as much right whale oil as sperm whale oil was shipped from Sydney, the destination of the product from New Zealand bases. By 1845 there was practically none. The right whales had gone, and with them the associated industry.

In the New Zealand region there has also been an apparent increase in sightings over the last decade, although the statistics have not been systematically collected. Y FIRST ENCOUNTER with the species was in Southland’s Te Waewae Bay in August 1990. From a small boat the sheer size of the animals was daunting; their loud, resonant expiration of air — awe-inspiring. One 15-metre individual manoeuvred within centimetres of our aluminium runabout and poked its barnacle-clad head out of the waves to have a look at us. It is thought the callosities on the head deflect water away from the twin blowholes and form scrapers used in courtship battles. They have given rise to the nickname for the species — Barnacle Bill — given first to a friendly individual off the Napier coast by local fishermen. During my three years in Invercargill, reports of right whales around Foveaux Strait, Stewart Island, the Catlins and Fiordland have become quite common during the winter months. In successive winters a pair of right whales have nosed into Bluff harbour, much to the delight of locals. Even Southern Air flights from Stewart Island have deviated from their

usual flight paths to treat passengers to a view of one of the world’s largest and rarest mammals. RARE INSIGHT into the behaviour of these whales was gained by Ramari Stewart, a staff member at the Campbell Island Meteorological Base in 1983. She observed whales in North West Bay from when they first appeared in May until they left in September. She kept careful notes and discerned a distinct pattern of behaviour around the bay. One section of coast she named "Whale Road" because of the way whales repeatedly cruised in and out of the shallow coves, sometimes resting their bellies on the bottom. Cows first arrived

with young calves and showed little interest in bulls until mid-July when, she assumes, they came into oestrous. Loud blowing noises, breaching, fluke slapping, and rolling in the surf followed. When cows wished to avoid the attention of males they simply swam upside down, their genitalia out of the water. As well, Ramari observed purely playful behaviour. One sub-adult male repeatedly trailed kelp from its mouth to attract an entourage of a dozen young sea lions. Ramari estimated a population of about 30 whales at Campbell Island, suggesting a slight increase from the 1940s. Two whaling bases operated there between 1909 and 1916 and probably killed close to 100 animals. Ramari says it is important that a photographic inventory be developed for the Campbell Island whales, similar to the ones for whales in Patagonia, South Africa and Australia. The inclusion of a Department of Conservation employee among the year-long meteorological station appointments should help with standardisation of the whale observation programme. DoC’s principal conservation officer for marine mammals, Mike Donoghue, is proposing a long-term monitoring programme for the subantarctic populations and is seeking international support for a pilot study this coming winter.

The Auckland and Campbell Islands whales are the only remaining major breeding population which is not being monitored, he says. Donoghue proposes shore and boat-based observation to build up a comprehensive photographic catalogue, and the collection of skin tissue for genetic analysis against other breeding populations. There will also be interest this winter to see whether the pod of about ten right whales returns to Te Waewae Bay. If New Zealand whales breed about every three years, like the Patagonian population, then this is a possibility.

Genetic analysis and photographic cataloguing could provide clues as to the origin of this pod; whether they are vagrants from south-east Australia or overflow from the Auckland Islands population. IGHT WHALES are unique among whales in calving and mating so close to shore. Important conservation management issues will arise if right whales do start recolonising traditionally used areas of the New Zealand coastline. Some, such as

Wellington Harbour, may no longer be suitable as calving grounds because of shipping and port developments. Recent television pictures from South Australia showed the vulnerability of this species to entanglement in ropes and fishing gear. This coastal whale is also susceptible to habitat depletion, and their surface-feeding habits are unsuited to coping with pollution, particularly oil. Little is known of the effects of small boat traffic on whales in breeding bays, and a buildup of accessible populations would inevitably create commercial and recreational whale watching pressures. Nearly 60 years after right whales became the first whale species to be given full international protection, they are only Just starting to show signs of an increase. There is much to be learnt and many management challenges to be met if the comeback is to be a lasting one. %

is a writer

specialising in natural history and works for DoC in Invercargill.

Recognising your whale

IGHT WHALES are probably the easiest of the large whales to identify. They are the only ones without any dorsal fin and they have distinctive white callosities on their heads. They can also be distinguished by their blow — a distinctive V-shaped column of spray up to five metres tall, formed from the twin blow-holes Even from fleeting glimpses of their tails, right whales can be recognised by the curved, smooth blades and deep tail notch. Like sperm whales and humpback whales the tail is raised clear of the water when diving. The stocky body ofa stranded right whale should be easily recognisable. And from skeletal remains the spectacularly arched jaw bone should be a give-away. They are slow swimmers, cruising at less than two knots, and can sprint to about five knots. They usually breathe two or three times a minute for several minutes before making a

long dive lasting 10 to 20 minutes. In breeding grounds they have been observed "sailing" — thought to be a form of play — where the tail or flippers are raised and the animal sails downwind.

They communicate through a series of low-frequency moans, belches and pulsed sounds, mostly at night, but their acoustic behaviour is nowhere near as complex as that of humpback whales.