By Jo Meek
Producer, All Out Productions
On the warm shallow waters of the South Pacific a small boat rides unseasonably choppy seas.
The research team tags its first whale (Image: Lisa Walker)
Driving the boat is Nan Hauser, founder and director of the Centre for Cetacean Research in Rarotonga, the largest of the Cook Islands.
For the past nine years Nan and her seasonal team of whale researchers have been out on the water studying the behaviour and movement of the humpback whales that migrate past the Cook Islands each year.
They arrive here from the Antarctic feeding grounds to mate and give birth in the warmer tropical waters.
Every year between July and November brings new whales; Nan Hauser rarely sees the same ones in successive seasons.
So where do they go year on year? This season, Nan hopes to expand her knowledge of the humpbacks by keeping track of at least some of those that pass through.
It is an ambitious task, especially as this winter season, unusually, has brought choppy seas and bad weather.
However, Nan and Ygor Geyer, an expert whale tagger who has travelled from Brazil for this project, are both determined to be the first in the South Pacific to place satellite tags successfully on three of the humpbacks.
"We have no idea where the whales go or where they are from," says Nan Hauser.
"All we know is that they feed in the Antarctic and use the Cook Islands as a corridor to pass through.
"It's the perfect place to satellite tag because we have no re-sights of whales from previous years; that does not happen anywhere else in the world that we know of."
It is a month since Ygor arrived from his own tagging project in Brazil; but in the Cook Islands he has yet to tag a single whale, and time and the weather are not on his side.
The task is not an easy one. It sees Ygor standing at the bow of their small boat as Nan negotiates the rough ocean, holding a 18ft (5.5m) pole which has at one end a 10in (25cm) tag.
This will not hurt the whale. The animal has such a thick level of blubber that the tag merely pierces the skin and rests near the surface to be switched on automatically every three days, allowing Nan and her team to track the whale's journey by GPS.
Nan has to position Ygor the right distance away from the whale to allow him to place the tag just below the dorsal fin. He needs a good steady hand; and, he says, he will not tag unless he is completely sure there is no risk of harming the whale.
But it is a dangerous job: a grown humpback whale is at least twice the size of the boat and could easily capsize it. Nan and Ygor both have years of experience between them and believe their research is worth any risks they may face. But is the wait becoming a frustration?
"We have spent months waiting to go out to tag in Brazil because of the weather," says Ygor.
"Sometimes we have only one or two days that are any good to work; so no, I'm not frustrated, but I do want to get out there."
But first they have to find the whales; and just as the rain starts to pour - on the day Ygor the whale-tagger was originally due to go home to Brazil - a whale is spotted.
It does not take the team long to get close, but they do not have much time as they refuse to chase the whale, an aggressive manouevre with which neither agrees.
Ten minutes after they first see the whale blow, the first tag has been deployed. It is on a cow (a female humpback whale), followed closely by her recently born calf.
The whale research team in Rarotonga is jubilant. It will allow them to track the travels of this humpback for the next three months and piece together some interesting facts about a mammal about which little is known.
But for Nan that is only one reason for this project; she is looking at the bigger picture, the future population of the humpbacks.
The team: (R-L) Nan Hauser, Fredrik Christiansen, Silvia Morelli, Lisa Walker
"We learn so much about the whales from tagging them - the migration, the speed of travel, the interchange between different countries and islands.
"The Japanese are looking to add humpback whales to their quota [of whales hunted in the Antarctic each year]. If the Cook Islands whales swim into the Japanese killing areas, it has been suggested by the Cook Islands government and its people that we may be able to demand that they are not allowed to kill 'our whales'."
As e-mails and calls of congratulations come into Nan and her team, the researchers manage to tag a second whale, "Jamieson" as she has become known.
The satellite shows that both whales are travelling long distances; the first to be tagged is heading north towards French Polynesia, travelling over 100km (60 miles) in just 24 hours.
It is one more piece of the puzzle that adds to the researchers' growing picture of the journey and behaviour of the humpback whale.
The Cook Islands Whale Research team hopes to successfully complete their tagging project with a third tag in the coming days.