The Department of Conservation is close to solving one very large mystery.
DOC is working towards cracking the genetic code of the nationally endangered southern right whale (tohora) using biopsy samples. Only a handful of samples are needed to complete the research and DOC is calling for public help by reporting sightings of southern right whales.
Department of Conservation marine mammal officer Steve Smith said, "We are well on the way to wrapping up the research project. Fingers crossed we’ll manage to obtain enough unique samples this year."
"In the last six years twenty two individual genetic samples have been obtained from whales around New Zealand, largely thanks to tip-offs from the public. We’re racing against time to solve this mystery so the quicker we can get the thirty unique samples we need, the better."
When completed the research will provide crucial information towards assisting the recovery of a threatened species.
Biopsy sampling will show if there are genetic similarities or differences between southern right whale populations in New Zealand and New Zealand’s sub-Antarctic Islands. Determining the New Zealand whales’ genetic make-up is vital in managing the population and assisting their recovery.
Southern right whales are in serious peril around mainland New Zealand with possibly very few breeding females remaining. To date no movement of whales between the mainland and the sub-Antarctic Islands has been documented, so it’s possible the whales around mainland New Zealand are both geographically and genetically separated from those that breed further south.
"If the New Zealand population is separate to New Zealand’s sub-Antarctic Islands we need to know. We can then take measures to ensure the whales have the right level of protection from any potential threats, such as marine farms, ship strikes and coastal developments," said Mr Smith.
A sighting of ten whales in Te Waewae Bay last month gave DOC marine mammal staff a great opportunity to increase the number of samples.
Two pods of whales were reported by a Southwest helicopter pilot flying over Te Waewae Bay. Later that afternoon DOC staff located the whales and took identification photos.
"Individual whales can be identified by the unique pattern of the white callosities on their heads," said DOC Biodiversity Ranger Sue Lake. "We also managed to get close enough to the whales to collect five biopsy samples using a dart gun to collect a tiny piece of whale skin. After the dart bounces off the whale it floats and we scoop it up. The samples have been sent off to the University of Auckland to analyse the DNA profiles."
Southern right whales spend a large portion of their winter breeding months, June - September, very close to the shore in sheltered waters sometimes resting on the ocean floor with their blowholes above the surface.
Ms Lake said, "To have ten whales in Te Waewae at one time is really special and both the pods included a calf, which is great. We had quite a few phone calls from the public who had noticed the whales. Due to their huge size and the amount of time they spend close to the shore it’s easy to spot them when they are close to land. This time of year is a rare opportunity for members of the public to see large whales and to help DOC with our crucial research."
DOC asks the public to report sightings of the whales to its 0800 DOC HOT line (0800 362 468) and where possible to photograph the whales.
What to look for
Adult southern right whales are on average 15 metres long, and newborn calves, between four metres and six metres. They are mostly black in colour and can be identified by their lack of a dorsal fin, a V-shaped blowhole spray, and white growths on their heads called callosities. Each whale has a unique callosity pattern.
What to do if you see a southern right whale
Southern right whale sightings should be reported to DOC, preferably as soon as possible after the sighting is made, on 0800 DOC HOT line (0800 362 468). DOC needs to know the date, time and location of the sighting; the number of whales; whether there were any calves; and their direction of travel.
Photos help identify individual whales, especially those of the left side of the head, and of the full body length.
Whales should be approached slowly, quietly and cautiously, and no closer than 50 metres, preferably from behind or parallel to them. Boaties are requested not to obstruct their path, cut through a group or separate mothers from calves, and to turn off their engines if a whale approaches their vessel. Sudden noises may startle the animals and should be avoided. Aircraft should keep a 150 metre distance from whales and not fly directly over them.
The whales were hunted extensively along the coasts of New Zealand from the beginning of the 19th century, resulting in a population collapse from approximately 17,000 whales to about 1000 today.
They are called southern right whales for the wrong reasons – named by early whalers because they are slow moving, were easily hunted, float when dead and provided large quantities of valuable oil and whalebone. They were therefore the ‘right’ whale to hunt.