|
The
Center for Cetacean Research & Conservation
Cook
Islands Whale Research Project
Report
for the year 2002
The 2002 field season,
between June 14 and October 27, 2002 was not as successful as previous
years due to high winds and bad weather. There were 59 whales sighted
as opposed to 82 whales sighted last year (group size 1 to 3) during
31 humpback encounters documented over a period of 105 days of observation
by the research team and many more sightings by fishermen, dive boat
operators, tourists and islanders. Because of the bad weather only 76
days were spent on the water. Other observations were conducted from
shore. A total of 430 hours 16 minutes were spent combining the effort
of R/V Kaukura Whale Research Vessel and F/V Te Mana Karere captained
by Wayne Barclay.
Antarctic minke whales were sighted twice off of Rarotonga by dive boats,
the occasional breaching sperm whale was observed way off shore, and
dolphins were reported only twice during the humpback season. There
was one long liner / cetacean encounter on December 22nd where the bodies
of most of the fish were eaten off the lines. Approximately 60 to 70
"dolphin-like" animals (probably pilot whales) were reported
to be in the area of the "set" the day before
Peponocephala electra (melon headed whales) were observed in Penrhyn
on 2 encounters/ December 14th, 2002 and again in February, 2003.
Two humpbacks were reported off the reef in Penrhyn in August.
Days were spent
on the water at every opportunity depending on weather. Skin samples
were collected for DNA analysis and sent to the laboratory at the University
of Auckland. Along with these samples was a piece of whale bone from
a stranded humpback skull that washed up in Aitutaki in July. A previous
piece had been sent to the lab with last season's samples but immigration
officials in New Zealand fumigated the bone and affected the DNA. The
new piece has been delivered to the University laboratory where it will
be analyzed. A sperm whale that stranded on the reef in Palmerston had
its lower jaw removed by Bill Marsters (Fisheries) and I have taken
a tooth to the University of Auckland biological laboratories for a
scraping to sequence the DNA. Skin, tissue and teeth from the stranded
fraser's dolphin in Rarotonga were also transported to the lab for analysis
to confirm the species. The dolphin bones are still soaking in water
to remove tissue.
Skin Samples from Humpback Whales
Genetic material
(DNA) coded with individual whales' attributes were gleaned from samples
of the humpback whales skin and body parts. Sloughed skin samples were
collected by diving into the footprint of the whale at the surface of
the water as they fluked, tail slapped or breached. No samples were
collected with a cross bow and biopsy dart this season. A biopsy gun
has arrived from "Pax Arms" in New Zealand, to make skin and
lipid sampling more efficient and less traumatic to the animal. The
President of "Pax Arms" happened to be on holiday in Rarotonga
and spent half a day with me, going over the protocols and details of
using the gun. Samples were flown to Auckland with the appropriate permits
and transferred to the biological lab at the University of Auckland.
There they are logged with a unique access number, allowing cross-referencing
of photo-ID and field data recorded simultaneously. Samples are preserved
and stored according to established protocols for later analysis. DNA
is subsequently analyzed to determine the sex and relatedness of individuals
and to assess the population identity of Cook Islands whales. Teeth,
baleen, organs and other body parts are collected from dead specimens
for analysis and determination of death. The remains of the 2 beaked
whale skeletons (Ziphius cavirostris) collected on Manuae in June of
2000 for Cook Islands Whale Research, have been studied by CCRC staff,
Merel Dalebout (beaked whale geneticist) and Robert Brownell of Southwest
Fisheries. They are still waiting to be analyzed by Darlene Ketten of
Wood's Hole Oceanographic Institute and Massachusetts Eye and Ear Hospital.
The bones are now on display at the Whale Education Centre in Rarotonga.
The blue whale vertebrae found behind Harbour house is also on display
with a variety of bones from around the islands.
Turtle shells have been loaned to the center by Mel Abuthnott and Iaoba
Marsters Sr.
A boiling pot for whale blubber is on loan to the Centre from the library
and an original whaling harpoon from a local man.
Significant
findings
This season's song
was almost non-existent. We had only one and a half days of song on
October 14th and 15th. Two hours of song were recorded on the 14th of
October off of Matavera Point and Sand River. Song was also heard off
of Black Rock the same day yet the wind had picked up and the recording
was poor. On the contrary, whale song was abundant throughout the 2001
season. The year before that, during the 2000 season, there was a lapse
of song for approximately seven weeks from August 1st to September 17th.
The song was recorded on DAT tapes and will be sent to Michael Noad
along with the whale song from 1998, 1999, 2000 & 2001. I am in
the process of transferring the Digital Audio Tapes to CD format. He
will also compare the song to that of Eastern Australia, New Caledonia,
Tonga, and French Polynesia. Dr. Michael Noad has officially become
a member of the South Pacific Whale Research Consortium and will be
the acoustician for the recordings from the Cook Islands and other nations
across Oceania.
What we heard of the song this year was a typical variation of the year
before.
As mentioned in last years report, on the 27th of August, 2001, a whale
was recorded singing an entirely new song.
(WP #207 South 21°11.960 West 159° 49.282)
We called it the "creaky door, broken chainsaw, laughing monkey
song". Despite it's strange composition, the "laughing monkey"
phrase was incorporated into the Cook Islands whale song on September
2nd, 2001 . This whale sang a continuous song for 84 (eighty four) minutes
without a break.
(WP # 218 South 21°14.329 West 159°50.487)
Recordings were made for the entire time sequence. This was of great
interest to the whale community and the acousticians, although it is
believed that he had to come up for a breath or two during that time
even though he was not observed doing so. Often when a male is singing,
he will continue the song as he surfaces, with barely an exhalation
(with no visible blow) and inhale quickly at the surface without stopping
the song. (note: We have heard whale song off of Rarotonga almost every
day of the 2003 field season)
Whale Song
The whale vocalizations
were recorded using hydrophones (underwater microphones) and a Sony
DAT recorder. Photo-IDs, video, and skin samples were collected from
singing humpbacks whenever practical. Song structure and form will be
compared among the Cook Islands' humpbacks and with songs recorded at
other breeding grounds across the South Pacific and around the world.
Because humpback song varies geographically, comparative analysis of
song will be used in addition to comparative genetic techniques to determine
the stock identity of Cook Islands humpbacks.
Some analysis has been done on the whale vocalizations between the mother
and calf from the encounter where the calf was in distress. The calf's
vocalizations increased when the mother left the immediate area with
a male escort and left her calf behind with our research vessel. This
is when the calf actually swam to the research vessel and attempted
to nurse on the side of it.
We did not experience
the level of competitive behaviour again this year as we had in 2000
when we had observed a male displacing another male from a group of
3 animals on the 11th day of observing this particular whale named Woodie.
He traveled with 2 females counter clockwise around the island where
he encountered another male with whom he displayed aggressive behaviour
with ramming, pushing, and chasing. (note: We have observed 3 months
of competitive behaviour between males during the 2003 field season)
Mothers and
Calves
In 2002 we had 15
encounters with mothers and calves. It appeared that Rarotonga was used
as a "nursery grounds" this season as we had very few escorts
and only 2 days of singing during the entire season. Note: in 2003 escorts
were abundant and we observed frequent competitive behaviour.
No aggressive behaviour
from females was displayed as in the year 2000 when a female accompanied
by her young calf and an escort, rammed the research vessel twice, blowing
bubble screens as a warning and exerting impressive powerful exhalations
from her blowholes.
The strange behaviour* from the calf in September of 2000 has to date
still not been explained and has fascinated fellow researchers that
have watched the underwater footage. Wally and Trish Franklin from the
Oceania Project in Hervey Bay, Australia have reported to me that they
have observed a calf jaw popping at the surface only once for no definitive
reason. This is the only other record of the jaw popping behaviour that
I am aware of. (This footage was shown at the 2003 International Marine
Mammal Conference with interesting feedback.)
(*loud jaw clapping,
expelling air from it's blowholes underwater and displaying arching
and jerking motions with his body. Approximately 17 days later the calf
still appeared to be troubled with digestive ailments and vomited with
its mouth wide open at the surface.)
The regurgitated
milk (gastro-esophageal reflux) that was collected from the calf will
be analysed for milk proteins.
Baleanoptera
bonaerensis?
No further identification
was made to the strange whale that was observed in early October of
2000. After sending the data to various whale researchers, it seems
that no one can identify the species of this whale. The suggestions
range from either a strange variation of a pygmy brydes whale, a pygmy
blue whale, a hybrid or possibly a new species. The suggestion by Bob
Brownell and Robert Pitman is that the whale is an Antarctic Minke Whale
(Baleanoptera bonaerensis) but has since been challenged by others in
the field, including myself. Bob Brownell was in Rarotonga at the end
of the 2002 whale season and we spent quite a bit of time analyzing
the footage of a Baleanoptera bonaerensis that he had on film. The head
was distinctly different and Nikki Rumney from The Dwarf Minke Whale
Project in Australia has also commented that it does not look like a
true southern minke whale.
Both the Cook Islands,
New Caledonia and Moorea had fewer whales this year. At the consortium
meeting in Auckland last week (end of February) we compared our tail
fluke ID's with those of Moorea's over past years to determine whether
the same whales that frequent their waters veered off to the west and
migrated past Rarotonga this year as an alternative. Again the results
of the "matching workshop in Auckland were surprising since we
had only one tail fluke match with Moorea in 1999, only one dorsal fin
match in 2000 and no matches in 2001 or 2002. This suggests that they
are distinct populations. The DNA samples from the 2000 and 2001 season
are being analyzed by Carlos Olavarria, working under Dr. Scott Baker
at the University of Auckland.
Tonga
We had our fifth,
sixth and seventh match with Tonga at this years Consortium meeting.
(February 2003)
1) Humpback Whale: CIMn / Rarotonga on 28 August, 2002 with
ID #Tg 9920 in Tonga on September 11th, 2000. ( 2 adults together)
2) Humpback Whale:
CIMn / Rarotonga on 27 September, 2002 with ID #Tg 9920 in Tonga on
September 1st, 2000.
3) Humpback Whale:
CIMn / Rarotonga on 11 August 2000 with ID# Tg 02/50 in Tonga on September
5, 2002 / escort with + biopsy.
Niue
No other work has
been conducted in Niue since we discovered a match between a whale seen
in the Cook Islands in 2000 and Niue in 2001.
Humpback Whale (Cimn
#031/00) in Rarotonga on 7 August, 2000
Humpback Whale (AM01/09, frame 18a) in Niue on 26 August, 2001.
This is the first
match with Niue. Minimal photo identification work has been done there
in the past. Only 2 tail flukes were collected there in 2001 during
a short study. The observation team reported 2 mother / calf pairs.
Other matches were made during last weeks meetings between New Caledonia
and Eastern Australia, and New Caledonia and Tonga.
IWC
With the upcoming
IWC (International Whaling Commission) meeting convening in Berlin at
the end of May and June, much of our discussion at the consortium meeting
involved politics and the threat of the whaling industry increasing
their quotas.
Environment Australia has funded the Consortium with $50,000 (Australian
dollars) to pursue our research in Fiji and Vanuatu. The grant is directed
towards creating whale sanctuaries across Oceania.
Beaked Whales
With beaked whales
and other cetaceans we will continue to document their presence and
the construction of a photo-identification catalog. Depending on our
encounter rate, more research should follow. Graham Ross in Australia,
has shown interest in comparing the findings of beaked whales in the
Cook Islands with those in other countries.
We had 2 encounters (total 7 animals) with Mesoplodon densirostris during
the field season, both occurring on the same day. Photos and video were
taken.
Fraser's dolphin
On September 27th,
2002 a young dolphin beached itself in the shallow water of Rutaki.
A swimmer found the dead dolphin and promptly called the "whale
research" cell phone to report the finding.
The animal was (waiting for DNA to confirm species) a young Fraser's
Dolphin (Lagenodelphis hosei) and was evidently killed from 3 large
cookie cutter shark bites.
A total necropsy was conducted on the animal, filmed in digital video
and photographed. Since that stranding, no dolphin sightings had been
observed until January 26, 2002 when Melvin Arbuthnott observed 8 spinner
dolphins off of Black Rock. Fishermen saw few dolphins this year off
of Rarotonga but the resident pods in Palmerston and Aitutaki are reportedly
doing well.
This was the first documented sighting of a Fraser's dolphin in the
Cooks.
This species was not scientifically described until 1956 and was not
seen alive until the early 1970's.Because it's appearance falls between
Lagenorhynchus and Delphinus, it has been called a Lagenodelphis. A
Fraser's dolphin has a shorter beak, a smaller dorsal fin and tinier
flippers than a spinner dolphin.
Analysis of prey suggests that the Fraser's dolphin is a very deep diver
and can hunt for fish at depths of 250 to 500 metres. This may be consistent
to why they are susceptible to cookie cutter sharks that we think may
live at depth.. No one has ever observed a cookie cutter shark in the
wild other than being caught in nets accidentally or on long lines.
Distribution is poorly known. Most commonly seen in the Eastern Tropical
Pacific near the equator and in the Philippines at the southern end
of Bohol Strait. Confirmed sightings are from Madagascar, the east coast
of South Africa, Indonesia and Sri Lanka. Other sightings include Japan,
Taiwan and off of Australia in small numbers. Michael Poole reports
that they have been observed off of Moorea in French Polynesia.
A newborn animal is approximately 39 inches or 1 metre. An adult reaches
6 1/2 to 8 1/2 feet or 2 to 2.6 metres.
They are frequently found in large schools often mixed with other pelagic
cetaceans &rarely seen in inshore waters except around oceanic islands.
Rules and
Regulations
With the help of
Cook Islanders, the New Zealand Department of Conservation, Marine Resources,
World Wildlife Fund, The Center for Cetacean Research & Conservation
and the Cook Islands Police Department, I have developed a set of protocols
and regulations for Whale Watching in the Cook Islands.
Dr Woonton has expressed a very wise set of rules that will help keep
our whales safe and ensure that they will not be harassed in the waters
of the Cook Islands. This is by encouraging whale watching from the
shore since our reef is so close to the land and the whales come right
in against it.
Dr. Woonton's motto is "In the Cook Islands, we don't go to the
whales, they come to us." This will hopefully ensure that the whales
keep passing by the Cook Islands on their migration. Other countries
have talked about adopting this idea by his leadership.
I have continued
to present lectures and videos to schools and local groups with excellent
results. School groups will integrate the Whale Education Centre into
the school curriculum.
I need to express
enormous thanks to :
Joan Hauser Daeschler
Helen Hauser Jordan
Doug, Julie, Drew & Ross Macrae
Tap Pryor & Phil Clapham
The South Pacific
Whale Research Consortium
Karl and Sue Trayler
Wayne Barclay
Michael Tavioni
Cook Island Divers
Dept. of Marine Resources
International Fund for Animal Welfare
Ali, Jody & JulieAnne and Scott Nelson
And all of the fishermen, school children and tourists that reported
whales.
Whale Sanctuary
Again,
thank you so very much to the politicians and friends that made the
whale sanctuary a reality. Especially Dr. Woonton., George Pitt and
Tap Pryor.
As
always I submit this report with great enthusiasm. As we unfold the
mysteries of these ageless leviathans, I am in awe of their greatness,
their gentleness, their beauty and just how much more we have to learn
from them.
Thank
you so very much to the Cook Islands Government and for all
of the support & help from everyone in the Cook Islands that have
made
this research project a huge success!
Respectfully submitted
by Nan Hauser, April, 2003
Cook Islands Whale Research.
P.O. Box 3069
Avarua, Rarotonga |