Research

Large Whale Tail

The Center for Cetacean Research and Conservation (CCRC) conducts and facilitates benign research on whales and dolphins.

The conservation status and biology of most cetaceans are poorly understood. Many cetacean populations are threatened; quite a few are endangered. All are susceptible to humankind’s interference with marine ecosystems. Multidisciplinary scientific research is needed to develop appropriate conservation strategies. CCRC has undertaken studies on the biology, behaviour, and ecology of a variety of cetaceans.

In 1996, CCRC researchers began documenting populations of bottlenose dolphins, spotted dolphins, and dense-beaked whales in the Bahamas. CCRC efforts have revealed a novel feeding technique by bottlenose dolphins, the first underwater footage of beaked whales, and underwater footage of a sperm whale with a broken jaw.

In 1998, CCRC initiated the Cook Islands Humpback Whale Survey, a long-term study of the depleted, yet unstudied humpback whales of the central South Pacific. This study focuses on humpbacks while they are in the waters of the Cook Islands, a chain of 15 islands in the central tropical South Pacific. Humpbacks frequent the Cook Islands during the austral winter to breed and calve. The Cook Islands offer an unprecedented opportunity to study the status and population identity of humpback whales in the central South Pacific, information vital for developing appropriate conservation measures for this endangered species.

Research Objectives

  1. Document population of humpback whales and other cetaceans.
  2. Photo-identification of individual animals using digital imaging and digital video.
  3. Document distribution of cetaceans within the area and compare this to the distribution of other species of marine life and oceanographic variables.
  4. Opportunistically collect 1) sloughed skin; 2) biopsied skin; 3) blubber samples; 4) faecal samples for genetic and hormonal analysis; and 5) opportunistically and non-invasively collect animal bodily fluids and tissues from live or dead animals.
  5. Carry out surface and underwater behavioural observations of dolphins and whales.
  6. Record and assess diving behaviour of humpback whales, beaked whales, and sperm whales in the area.
  7. Involve and engage Cook Islanders in the research process to further their understanding of and commitment to marine conservation through public outreach sessions offered to schools and community groups.
  8. Opportunistically film television documentaries and news stories, and write magazine articles and blogs.
  9. Rescue and rehabilitate cetaceans that “strand” themselves on the shores of the Cook Islands.
  10. Share data with the members of the South Pacific Whale Research Consortium to compare and publish findings.
  11. Examine the DNA of each individual whale to determine genetic relationships, common ancestors, and migration routes using genotype matching.

Conservation Initiatives

  1. Providing curriculum enrichment and community outreach programs.
  2. Publishing scientific findings in both professional and popular formats through various media.
  3. Offering practical experiences for interns and volunteers.
  4. Providing educational films for television and movie theatres.
  5. Including the local community in cetacean “strandings.”
  6. Collaborating with and facilitating organisations and individuals of complementary purpose.

 

Humpback Whales

Whale Tail Coming Out of the WaterHumpbacks are the most studied of the large whales, yet much of their basic biology remains unknown. There are few estimates of Central South Pacific humpback population parameters, until recent studies.

Humpbacks have been hunted extensively in the South Pacific by commercial and pirate whalers as recently as 25 years ago. Indeed, disregarding an international moratorium on high seas whaling, several nations are clamouring to resume the hunt in these waters. Small island nations of Oceania are especially vulnerable to financial incentives offered by countries that continue to hunt whales. The Cook Islands have led the way in whale conservation by claiming a 2 million square-kilometre whale sanctuary in their exclusive economic zone. Other countries have followed suit, including French Polynesia, New Caledonia and Niue, Palau, Tokelau, Tonga, Kiribati, and other island nations.

The Cook Islands offer an unprecedented opportunity to study the status of humpback whales in the Central South Pacific, information vital for developing conservation measures for this endangered species.

We used the scientific data collected from New Caledonia, Tonga, the Cook Islands, and French Polynesia to successfully list the humpback whales across Oceania as “endangered." This is an enormous feat in the protection of the whales and has prevented the Japanese whalers from being able to add humpback whales to their harvesting quota.

Various behaviours are observed both on the surface and underwater. CCRC collects valuable data and footage including but not limited to: diving behaviour, mother and calf relationships, male escort relationships, group structure, male competition, and migration.

Satellite Tagging

Satellite tags are carefully placed on humpback whales to determine migration patterns. Whales are tracked via satellite and their GPS positions are downloaded via the ARGOS system. CCRC involves schools and classes in Rarotonga, and through local television and newspapers, we plot the paths of these tagged humpbacks.

Little is known about the winter movements of these animals, and there is no information regarding where they feed in the Antarctic. The Cook Islands aggregation appears to be small and transient, and recent photo-identification matches have shown connections with other areas (principally Tonga, but also Samoa, French Polynesia, and even New Caledonia).

In September 2006 and 2007, CCRC attached ARGOS satellite-monitored tags to eight humpback whales of various sex and behavioural classes. All whales were tagged in the near-shore waters of Rarotonga. We reported the movements of seven whales satellite-tagged in the Cook Islands, including the first documented migration to an Antarctic feeding ground.

Transmitters were attached to a stainless steel anchoring system. Satellite transmitters (Wildlife Computers implantable SPOT3/4) were deployed in humpback whales in the Cook Islands on the left or right flank of the whales, about 1 to 2 m ahead of the dorsal fin, and usually within 2 m from the midline of the whale’s body. This was accomplished using an 8-m pole deployed from a small motorboat. We repeated this study in 2014.

Opportunistically, we tag other species (i.e. sperm whales) if the circumstances are appropriate. Along with a pole, we use a small firing system for more accurate attachment.

Acoustics

Male humpback whales sing long and complex songs in the waters of the Cook Islands and other winter breeding grounds in the tropical oceans. Since male humpbacks usually only sing during the breeding season, it is likely that the song serves a reproductive function. The song may serve to attract females, to assert dominance among other males, or to maintain a distance between courting males. Songs are recorded using hydrophones (underwater microphones) and M-Audio digital recorders. Photo IDs, videos, and skin samples are collected from singers whenever practical. Song structure and form have been compared among the Cook Islands’ humpbacks and 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. Moreover, analysis of song and singers’ behaviour should yield insights into the functional significance of the humpback song. In the 2001 field season, we recorded a humpback whale off of Rarotonga with a new and different song. Within the next 10 days, the humpbacks in the Cook Islands waters included a phrase of the new song into their familiar repertoire. We are working with acousticians Michael Noad in Australia and Ellen Garland at Oregon State University to analyze the acoustic data collected across the region. It appears that certain phrases of the whale song are passed from West to East over subsequent years. We (the South Pacific Whale Research Consortium) have published a paper in SCIENCE entitled “Dynamic horizontal cultural transmission of humpback whale song.”

2019 humpback season brings Dr. Ellen Garland back to Rarotonga where we will continue studies of horizontal cultural transmission of humpback whales.

Using sound analysis software, we discovered four new songs that had emerged in a population in Eastern Australia and gradually spread to the East. Within two years of the new song’s creation, whales in French Polynesia were singing the same version. It was passed through the Cook Islands.

Photo Identification

Identification photographs (photo IDs) are taken of the uniquely marked flukes of each whale encountered. Photo IDs are acquired using digital still cameras equipped with telephoto and zoom lenses. Distinctive markings and behaviour of whales are recorded with digital video cameras on the surface, and when necessary, underwater. Field data, including behavioural mode, individuals present, geographic position, date, time, etc. are collected with voice recorders. All images are digitized, and data are transcribed and subsequently integrated into databases. Photo IDs and video stills are entered into a humpback photo ID catalogue to monitor individual whales’ residence and patterns of association.

Humpbacks of the South Pacific often dive without fluking, which is problematic for getting photo ID shots of their flukes. In response to this low fluke rate, CCRC researchers photograph humpbacks underwater. High degrees of lateral pigmentation have been documented on a large percentage of the humpbacks observed in the Cook Islands, which makes underwater photo-identification a feasible alternative. Whenever possible, underwater fluke shots are taken in addition to the more easily photographed lateral pigmentation shots.

Genetics

Genetic material (DNA) encoded with individual whales’ attributes can be gleaned from miniscule samples of their skin. These are collected by two methods:

Skin sloughed off as whales dive, tail slap, or breach is collected whenever possible.
However, since skin is not sloughed predictably, skin and blubber samples are also collected with a small biopsy dart fired by a biopsy gun when necessary. The biopsy gun is registered with the Cook Islands Police Department. Samples of both types 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 will be subsequently analyzed to determine the sex and relatedness of individuals. On a larger scale, samples are compared with those in existing databases to assess population identity of Cook Islands humpbacks and genetic diversity in humpbacks worldwide.

Toxicology

The long lives and high lipid content blubber of humpback whales predispose them to be severely affected by exposure to chronic contaminant burdens. Since little research of this nature has been conducted, portions of the biopsy samples collected for genetic analysis will be analysed for toxic contaminant burden and biomarkers of likely risk to evaluate the toxicological status of the Cook Islands humpbacks. Other biopsies will be frozen and shipped with a CITES export permit to universities for analysis.

Surveys

Opportunistic and systematic surveys of humpback whales, beaked whales, dolphins, and other marine mammals are conducted in the EEZ of the Cook Islands. The main goals of surveys are to:

  1. Document population identity and photo IDs of humpback whales and other cetaceans.
  2. Document distribution of cetaceans within the area and compare this to the distribution of other species of marine life and oceanographic variables.

 

Beaked Whales

Cook Islands Beaked Whale Survey

One quarter of the world’s 90 whale and dolphin species belong to the family of beaked whales (Ziphiidae), but because they favor deep-water habitats, study and knowledge of these cetaceans is in its infancy. Their conservation status is to this day unknown. Beaked whales are the deepest and longest diving of all cetaceans. In 2011, a tagged Cuvier's beaked whale dove to a depth of 2,992 meters, which is the deepest recorded dive by any mammal, and spent up to two hours and 17 and a half minutes underwater before resurfacing. What little we know of beaked whales has largely come from stranded animals. Sightings of these elusive creatures at sea are extremely rare due to their long dive times and unobtrusive surfacing behavior. Our research is currently looking at the group structure of beaked whales in the waters off the Cook Islands.

CCRC launched an opportunistic survey of beaked whales in the Cook Islands, South Pacific in 1998, which coincided with the establishment of the Cook Islands Humpback Whale Survey. We plan to take a closer look at the prey available to beaked whales and sperm whales in the Cook Islands. Nan recently visited with Charles Potter at the Natural History Museum for the Smithsonian Institute, and we will be starting a beaked whale stable isotope research project, looking at samples of skin and stomach contents of stranded beaked whales in the Cook Islands and Kiribati.

Critical Habitats

In order to protect beaked whales, we must determine their status. Elucidating their diving behaviour will yield much insight into their habitat requirements and possibly their food preferences. Dive data will enable us to fine-tune the pioneering assessment of habitat requirements of beaked whales in the Northern Bahamas and the Cook Islands.

Rather than being widespread across deep ocean basins, beaked whales are most frequently sighted over and at the edges of deep canyons, gullies, and walls, probably because their prey are associated with these features. As we learn more about beaked whale distribution, it appears that beaked whales rely on isolated critical habitats. To ensure the welfare of beaked whale populations around the world, these critical habitats must be identified and protected. A cooperative survey to identify beaked whale populations and their critical habitats around the world is in the making.

Acoustic Pollution

Cetaceans, because they communicate and navigate almost entirely using sound, are sensitive to acoustic pollution. Beaked whales, because of their peculiar physiology and deep diving, are especially susceptible to damage resulting from acoustic pollution. Threatening sources of acoustic pollution in marine environments include widespread oil prospecting, ice-breaking, shipping noise, and military sonar.

On dozens of the recent occasions when more than five beaked whales have stranded in a limited area over a short period of time, naval sonar tests were being conducted. The most dramatic of these events occurred on March 18th and 19th, 2000, when 17 cetaceans, 13 of which were beaked whales, stranded in the northern Bahamas. Nan Hauser assisted in collecting, documenting, and necropsying these whales. Several of the beaked whales’ heads were flown to Massachusetts Eye and Ear Hospital in Boston, Massachusetts, where Dr. Darlene Ketten (whale acoustic specialist) ran them through CT scanning machines. Ketten’s examination revealed unmistakable evidence of acoustic trauma.

Darlene Ketten visited the Cook Islands on July 27th, 2009 to work with us on 2 beaked whale heads that were in Nan's freezer in Takuvaine Valley. We analysed the heads and conducted necropsies. In October 2009, Nan sent ears, eyes, brains, and mandibular fat to Woods Hole Oceanographic Institute to be CT scanned. The results will be on display at the Whale and Wildlife Centre.

Small Cetaceans

A-POD: Small cetacean survey in collaboration with OSU and University of Auckland.
A pattern of dolphins [aPOD] - the seascape genetics of island populations in protected and unprotected habitats of Oceania.

Summary

The islands of Oceania extend from Melanesia in the west to far Polynesia in the east, representing the world’s most extensive habitat for insular populations of dolphins. The limited information available from two species in this region, the spinner and bottlenose dolphins, suggests that each forms a metapopulation with relatively isolated local populations connected by long-term or episodic gene flow. To understand this “pattern of dolphins,” Scott Baker proposed a large-scale study of the seascape genetics of these two species in strategic locations throughout Oceania, working in collaboration with members of the South Pacific Whale Research Consortium. The study locations will be chosen to represent spatial scales ranging from 10s to 1,000s of kilometres and to reflect contrasting histories of exploitation and protection, including existing and proposed Marine Protected Areas (MPAs). The seascape model will take into account information on habitat preference and abundance of dolphins available from independent aerial surveys planned for a large portion of the region. From this synthesis, it will be possible to assess the adequacy of existing MPAs for preserving local communities of dolphins, and to inform the design of new MPAs intended to help protect top predators.

Goals, Activities, and Outcomes

  1. Coordinate among members of the South Pacific Whale Research Consortium, including 36 independent researchers active in 10 Pacific Island nations or territories, to collect genetic samples from island communities of dolphins (principally, spinner and bottlenose) in protected and unprotected habitat selected to represent spatial scales from 10s to 1,000s of kilometres;
  2. Confirm species identity and describe the isolation or connectivity among dolphin communities and the influence of maternal fidelity and sex-biased dispersal using standard tests of differentiation and gene flow for mtDNA and nuclear (microsatellite) markers;
  3. Describe the spatial “seascape” of diversity and gene flow using models of isolation by distance and incorporating information on habitat preference and abundance from independent aerial surveys;
  4. Relate results of seascape analyses to the scale and proximity of existing or proposed MPAs to assess their adequacy to protect the functional role of dolphins as top predators;
  5. Identify centers of abundance and diversity of dolphins in Oceania for the purposes of proposing new MPAs.
  6. Contribute to local capacity building through training of fisheries and conservation officers in Pacific Island nations and policy outcomes through memoranda of understanding between South Pacific Whale Research Consortium, the Secretariat for the Pacific Regional Environment Programme (SPREP) and the Convention on Migratory Species (CMS).

 

South Pacific Whale Research Consortium

The South Pacific Whale Research Consortium meets every year. We have shared more than two decades of research together. Catalogues of fluke photographs were compared to describe regional return and interchange. Some degree of migratory interchange has been established between adjacent regions of Oceania (the presumed wintering grounds of IWC management Area V and Area VI humpbacks). Non-systematic surveys and unpublished capture-recapture estimates based on photo identification indicate that the density of whales remains low throughout the wintering grounds of Oceania and the New Zealand migratory corridor. Capture-recapture estimates of abundance for New Caledonia based on photo-identification and DNA profiling (genotyping) gave comparable results, indicating a small and possibly closed population of whales on this wintering ground. Genetic analyses are underway for sloughed skin and biopsy samples collected throughout the Oceania region. We have found genotype matches between the Cook Islands and other island nations across Oceania.

Raising Awareness

Increasing public awareness of whales and their conservation issues is essential for affecting informed decision-making about whale management. CCRC informs and engages in the Cook Islands, the United States, the Bahamas, South Africa, Australia, and New Zealand by: offering first-hand practical experiences for interns and volunteers; supplementing school curricula with educational enrichment programs; providing outreach presentations at public gatherings; distributing scientific findings to decision-makers; and contributing footage and photographs of whales, background information, and interviews for television, radio, and printed broadcast. Moreover, CCRC informs worldwide audiences through television documentaries, magazine articles, scientific journals, and several websites actively updated from the field.

Common Species Seen in the Cook Islands

  • Humpback Whale (Megaptera novaeangliae)
  • Sei Whale (Balaenoptera borealis)
  • Blue Whale (Balaenoptera musculus)
  • Dwarf Minke Whale (Balaenoptera acutorostrata) or
  • Antarctic Minke Whale (Balaenoptera bonaerensis)
  • Sperm Whale (Physeter macrocephalus)
  • Killer Whale (Orcinus orca)
  • Short-Finned Pilot Whale (Globicephala macrorhynchus)
  • Peale’s Dolphin (Lagenorhynchus australis)
  • Cuvier’s Beaked Whale (Ziphius cavirostris)
  • Blainsville’s Beaked Whale (Mesoplodon densirostris)
  • Common Dolphin (Delphinus delphis/frontalis)
  • Spinner Dolphin (Stenella longirostris)
  • Striped Dolphin (Stenella attenuata)
  • Fraser’s Dolphin (Lagenodelphis hosei)
  • Melon-Headed Whale (Peponocephala electra)
  • Risso’s Dolphin (Grampus griseus)
  • Bryde's whale (Balaenoptera edeni)
  • Fin whale (Balaenoptera physalus)
  • False killer whale (Pseudorca crassidens)
  • Pygmy killer whale (Feresa attenuata)
  • Rough-toothed dolphin (Steno bredanensis)
  • Bottlenose dolphin (Tursiops truncatus)
  • Spotted dolphin (Stenella attenuata)
  • Pygmy sperm whale (Kogia breviceps)
  • Dwarf sperm whale (Kogia simus)

 

For more information about our organisation’s benign research on whales, feel free to contact us.