Southland

Winter whale surveys spotlight rare species

Whale watching and the study of New Zealand’s diverse marine life is a major tourist attraction and a national pastime, but come winter the recreational activity takes on a more serious note.

With mammals on the move - some migrating north and others coming closer to shore to feed, rest and shelter - winter is the best time of year to spot some of the world’s rarest species around New Zealand’s extensive coastline.

But rather than just recording sightings for the family album, members of the public can help provide the New Zealand Department of Conservation (DOC) with vital information to establish patterns of migration, species and populations.

Sperm whales - northern migration
In Cook Strait, between the North and South islands, the 2009 winter whale survey has provided sightings of 46 humpback whales, and one sperm whale.

The official survey - conducted by DOC researchers and former whalers - was initiated in 2003 to assess the recovery of humpback whales since commercial whaling ended in 1964. The four-week 2009 survey ended on 14 July.

The survey coincides with the peak period for whales migrating to the South Pacific’s breeding grounds, and officials hope it will shed light on the mysteries of earth's largest mammals. The survey team looks at differences in the patterns of whale migrations, taking into account environmental factors such as water temperature and tidal patterns.

Visitors and locals are encouraged to report whale sightings with date, time, place, numbers and the direction travelled. Where possible, the survey team takes photographs and skin samples of the whales using a biopsy dart tool.

The 2008 whale survey recorded 37 humpback whales and four pygmy blue whales in Cook Strait. There are an estimated 2000 humpback whales in the Pacific and 10,000 in the southern hemisphere.

Southern right whales - cracking genetic code
DOC says public support could soon wrap up a research project aimed at cracking the genetic code of New Zealand’s endangered southern right whale (tohora).

A handful of biopsy samples would complete research, and clarify the relationship between southern right whales seen around mainland New Zealand and those from the sub-Antarctic region. With 22 genetic samples obtained in the past six seasons, researchers hope to reach 30 samples by the end of 2009 and solve the genetic mystery.

Whale movement between the mainland and sub-Antarctic islands has not yet been documented, so it’s possible the mainland whales are both geographically and genetically separated from those that breed further south.

The project is a race against time because southern right whales are in serious peril around mainland New Zealand. With few breeding females remaining, determining the whale’s genetic make-up is vital to population management and assisting recovery.

Southern right whales spend much of their winter breeding months (June - September) close to shore in sheltered waters, providing an opportunity to see the spectacular large whales from the coast.

Ten southern right whales were spotted in Te Waewae Bay - on the Foveaux Strait coast off Southland in June 2009 - and a mother and calf duo were seen off the Taranaki coast, on the western side of the North Island.

DOC says good quality photographs and tip-offs from members of the public have helped to identify individual whales assisting in the research.

Orcas go fishing in Auckland
Winter is also a good time to spot orcas - the distinctive black and white killer whales which are in fact the largest members of the dolphin family.

Residents along Auckland’s inner harbour suburbs were entertained recently by a pod of adults and baby whales that came close to shore. Hundreds of spectators gathered to watch the orcas as they leaped out of the water and tossed stingrays in the air.

Whale researcher Dr Ingrid Visser said it was common for orcas to swim near shallow waters when they were hunting for food. New Zealand orcas are the only group known to eat stingrays as a staple food.

Dr Visser, who set up the Orca Research Trust dedicated to orca in the South Pacific, tracked the new pod from the Kaipara Coast on Auckland’s northwestern coast and followed them to Auckland harbour.

She said orcas were easily recognisable because each animal looked different just like humans, and she gave the new visitors names - Roundtop, Funky Monkey, Porky, Fuego, Digit, Miracle and Magic.

NZ sea lion in rare appearance
Several sightings of a New Zealand sea lion, one of the rarest seals in the world, have excited DOC staff in Bluff, on the South Island’s southern tip.

New Zealand sea lions are endangered and numbers are declining so the large sub-adult male - resting on Bluff’s marine parade between feeding trips - was a rare occurrence, according to DOC staff.

Sea lions are generally confident around people but responses may vary. They may become defensive when approached, so DOC advised observers to stay at least 10m away and warned drivers to watch out for the visiting sea lion.

DOC workers investigated relocating the sea lion, but decided that could risk injury to the sea lion or the humans involved. It was also likely that the sea lion would return, making it a pointless exercise.

Sunfish at Farewell Spit
Tourists visiting Farewell Spit - on the South Island’s northern tip - have reported sighting a mink whale and a rare sunfish.

John Stevens, of Farewell Spit Eco Tours, said it was rare to see sunfish in the area. Measuring about 2m long, and 2m from fin-tip to fin-tip, this was one of the largest he’d seen.

Background: NZ sea lions

• New Zealand sea lions are fully protected under the Marine Mammal Protection Act.
• There are an estimated 12,000 New Zealand sea lions, but numbers are declining.
• Breeding is mostly restricted to New Zealand’s sub-Antarctic although some return to mainland New Zealand.
• Females give birth to a single pup every one or two years, in December / January.
• Threats to the sea lion population include drowning in trawl fisheries, disease and human disturbance.
• Sea lions eat a variety of prey. They can travel up to 175km from the coast to feed, and dive to 600m.
  

Background: Sunfish

• The sunfish or mola mola - the world’s heaviest bony fish - has an average adult weight of 1,000 kg.
• This unusual creature resembles a squashed rugby ball with twin rudders - fins that swish in a figure of eight movement, and stabilised by a large tail.
• Sunfish live mainly on jellyfish. This nutritionally poor diet means sunfish must consume large amounts to develop and maintain their great bulk.
  
• Females produce more eggs than any other known vertebrate.
  
• Sunfish are seasonal visitors to New Zealand moving into northern waters from November - June.
• Sunfish look clumsy but they can leap above water and are often mistaken for sharks when swimming near the surface.

Winter best for whale and seal spotters

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