The Return of the Whales

Forest and Bird, Issue 299, 1 February 2001, Page 14

The Return of the Whales

AND

— TONY

JENNY ENDERBY

TONY AND JENNY ENDERBY encounter the whales and dolphins of the Hauraki Gulf.

he sight of a large whale surfacing, its spout blasting upward, is unforgettable. From close range the sound has an almost resonant ring to it. The warm air from the whale’s lungs vaporises as it meets the cooler surface air, creating the spout that whales are best known for. We experienced both the sight and sound of a spout as a large whale circled our yacht. We were drifting, sails down, watching the best show in the Hauraki Gulf. Every

minute or so the whale surfaced, and dived again but never showed its tail above the surface. As it passed only metres from our stern we saw the massive tail, driving the whale silently forward, through the planktonladen water. This was a 14-metre Bryde’s whale which then moved off and joined several others nearby. We continued to watch. The whales rolled on their sides, occasionally showing a pectoral fin or part of a tail above the water, as they lunged through the masses

of fish and small crustaceans. There are more whales in the Hauraki Gulf than most people realise. The Bryde’s whale (pronounced broodahs), lives around the northern New Zealand coast most of the year. They are the whales most often seen, as they surface in a fish shoal feeding along with diving gannets. At Labour Weekend last, passengers on the glass-bottom boat at the Goat Island Marine Reserve, near Leigh, were given a

bonus when a large whale surfaced and blew close to the boat. Further away the curved dorsal fins of several others appeared at the surface. Immediately the passengers began to ask about the whales — ‘What kind are they?’ "Why are they so close to land?’ "What do they eat?’ ... and many more questions. Our answers were limited, as not much is known about these whales. We do know Bryde’s whales grow to 15 metres long, making them New Zealand’s largest resident mammal. They are found in most of the world’s seas where the temperature is more than 14° centigrade. The Department of Conservation is now doing studies of these animals to increase knowledge of the species. Other kinds of whale travel along the New Zealand coast as part of their annual migration from the Antarctic to the tropics and back each year. These include humpback, sperm, sei, minke, blue and fin whales. Humpback and southern right whales were probably common around the New Zealand coast until whaling began in the

early 1800s. Between 1843 and 1845 over 100 shore stations were engaged in hunting these ‘right’ whales. In addition, more than 200 whaling ships called at New Zealand ports annually and the effect on whales was massive. The southern right whale, which grows to 18 metres, was almost completely wiped out by 1850, but is slowly making a comeback at the Auckland Islands south of New Zealand. The whale most often seen in documentaries and photographs is the humpback whale. These magnificent animals grow to 16 metres and migrate between the Antarctic in summer and the Pacific Islands in winter, where they give birth and mate again. The 40-tonne animal can lift most of its body clear of the water in a display called breaching. It can also roll over and lift its long, white pectoral fins out of the water and let them crash back. During the winter of 1998, a pair of humpback whales spent a month in the Hauraki Gulf, between Leigh and Little Barrier Island, and the splashes as they breached were seen from the shore. During 2000, a large sei whale spent a few weeks in the same area, at times in the company of the Bryde’s whales. The recent change by the Japanese to include Bryde’s whales in their ‘scientific’ whaling hunts created outrage. This farcical use of the word ‘scientific’ is just an excuse to kill them, as the end result is still whale meat for the Japanese markets.

Perhaps this attitude is similar to the ‘scientific’ killing of the last huia for museum collections. Hopefully, it won’t have a similar end result. The whaling station that operated at Whangaparapara on Great Barrier Island, until the late 1960s, caught several Bryde’s whales but they were considered too slim to be economic. In late October 2000, a dead Bryde’s whale floated ashore near Leigh, and earlier that year three Bryde’s whales, between seven and 15 metres long, washed up on Great Barrier Island. Another dead Bryde’s whale floated into Omaha Bay in 1999 and another washed up on Pakiri Beach in 1997. Collisions with ships travelling through the Hauraki Gulf are thought to be responsible for at least some of these whale deaths. Our first experience of Bryde’s whales was while watching gannets dive into a huge fish school off Leigh some years ago. A dark, curved dorsal fin and back broke the surface in the middle of the melée. The whale spouted several times then dived again for five minutes without showing the spectacular raised tail of a humpback or sperm whale. Several more whales then appeared, in and around the feeding frenzy, which included common dolphins, petrels, shearwaters and gulls, as well as the gannets. Since then, we have recorded dozens of whale sightings in the Hauraki Gulf between Leigh, Little Barrier and Coromandel. In October, 1999 we recorded 42 spouts over a five-minute period, from a pod of Bryde’s whales a kilometre off Cape Rodney, near Leigh. Their most spectacular act is a half roll with a huge splash. Occasionally they ‘spy-hop’ lifting

their heads clear of the water. Usually Bryde’s are a shy animal and will move away from boats, dive for five minutes, and resurface several hundred metres away. New Zealand’s marine mammal regulations prohibit approaching closer than 50 metres to a whale. This is for the safety of both the whale and the boat. During exuberant whale mating overseas some scientists’ boats have been rammed and damaged. ther visitors to the Hauraki Gulf O are pilot whales. These large black dolphins, with bulbous heads, grow to around five metres long. They are well know for their unfortunate habit of beaching themselves in large numbers, usually on gently-shelving sandy beaches. Several hundreds have died around the coast over the years, although more recently whale rescue groups have managed to save many stranded victims. For most New Zealanders, whale or dolphin watching is a rare experience. A recent development has been the establishment of a dolphin and whale-watch venture operating in the Hauraki Gulf out of Auckland. Dolphins are the most common marine mammal in the Gulf, usually seen as they join boats for a bow ride. This activity brings great enjoyment to all who see it — it also appears to bring enjoyment to the dolphins. The two most common species in the Gulf are the bottlenose and the common dolphins. The grey, bottlenose dolphins are usually seen close to the coast and regularly visit harbours and estuaries to feed on school fish. We have been approached by bot-

tlenose dolphins when kayaking around the Leigh coast. They are delightful travelling companions and have developed a variation to the ‘dolphin on the bow wave’ trick. If we continue paddling they move alongside and under the bow of the kayaks. The bow moves upwards and the kayak speed doubles on the pressure wave created by the dolphins. A 3.5-metre bottlenose dolphin can create quite a wake. The common dolphin is less than two metres in length with dark grey on the top of their bodies, and white and cream on their sides and underneath. They live further offshore, and form pods of up to several hundred animals. In late autumn and early summer these groups move through the Hauraki Gulf, feeding on fish schools of mackerel and kahawai. From September to November we often see pods of these dolphin two to three kilometres offshore between Leigh and Little Barrier Island. When the pod is on the move dozens of dolphins can be seen jumping simultaneously.

rca, also known as killer whales, O are arguably the most beautiful and largest dolphin. Most pods consist of five to 15 of these distinct black and white animals. The large males grow to nine metres long and have a dorsal fin 1.8 metres high. Their visits to the Hauraki Gulf include travelling right up the Waitemata Harbour into Auckland. They hunt stingrays and eagle rays in the coastal shallows. In 1997, a pod of orca came into the Goat Island Marine Reserve and continued towards Cape Rodney. We drove to a vantage point above Leigh Harbour in the hope we would see them as they followed the coast. Below us, a pod of 20 bottlenose dolphins were playing in the harbour cove. Suddenly each dolphin turned as one and sped out of the harbour, into the open gulf.

About a minute later we saw the majestic sight of four orca dorsals, in line abreast, moving round the point and into the harbour. Dolphin was not on the menu that day but the dolphins seemed very aware that some days it is! It seems there may now be an increase in dolphin and whale numbers in the Hauraki Gulf, or perhaps there is just an increase in the number of observers. One thing is certain — the best kept secret of the Hauraki Gulf is now common knowledge. As long as the whales and dolphins are given respect, and space, more people will now be able to see and enjoy these gentle residents and visitors.

are

underwater photographers based at Leigh in lower Northland.

Bryde’s Whale Study in Northern New Zealand Waters study of Bryde’s whale numin the Hauraki Gulf is being made by the Department of Conservation. Led by Dr Alan Baker of DoC’s science and research unit, the study began in July 1999 with the objectives of determining Bryde’s whale numbers in the outer Hauraki Gulf, and their movements in, and migrations along, the northeast coast of New Zealand. After a pilot study it was found that the Bryde’s whales could be identified from the air. Regular flights were then carried out and the whales examined from 150 metres above and photographed. Four species of whale were identified; Bryde’s, minke, sei and one blue whale. Bryde’s whales, which are similar to sei whales, can be identified by three prominent longitudinal ridges on the rostrum — the head behind the blowhole — which are evident when the whale surfaces. The pilot study indicated areas of the Gulf where Bryde’s whales might concentrate at certain times of the year. The flight path was plotted on a GPS route, enabling repeat flights to follow the same track. The research from November 1999 to October 2000 indicated a concentration of Bryde’s whales in the Gulf from September to May. Usually groups of two to four individuals were seen, mostly feeding. They were often in massive ‘workups’ of gannets, shearwaters, and common dolphins and/or orca. Two calves were sighted in early summer. Few whales were sighted further offshore and these were usually travelling rather than feeding. The Bryde’s whales were noted to be in large concentrations in the spring of both 1999 and 2000. Other baleen whales were also present at this time. The whales appeared to come from the north rather than northwest, but there is no information on their whereabouts during the winter months. — Tony and Jenny Enderby.