Research Projects and Resources
The analysis of stomach contents from harbour and Dall’s porpoises is used to determine the diet of these small cetaceans. The stomachs are obtained from stranded animals collected through the Marine Mammal Incident Response Program (DFO Pacific Region) and animals killed by transient killer whales.
Sightings of small cetacean are collected during line transect surveys aboard large vessels. As well, incidental sightings are recorded and forwarded to the B.C. Cetacean Sightings Network. These sightings are used to help increase our understanding of abundance and distribution of porpoises and dolphins.
Fisheries and Oceans Canada has been conducting annual monitoring of resident killer whales for over 30 years, resulting in one of the longest continuous studies of any cetacean population in the world. The annual census of the resident killer whale population involves the use of photo-identification, a technique that was established in the early 1970’s by the late Michael Bigg. Using photographs to identify individual killer whales enables researchers to estimate population size by directly counting all individuals, and gives insight into social structure, birth and death rates, ages of individuals, and movement patterns.
- Northern Resident Killer Whales in British Columbia Photo-identification Catalogue 2007
The study of foraging ecology of killer whales uses various techniques including analyzing food remains from the stomachs of dead animals, observing predatory behaviour, scat analysis, and collecting scale and tissue remains left at kill sites. The species of prey is identified by analysis of scales (for salmonids) or by genetic analysis. This research has revealed that resident killer whales have a strong preference for Chinook salmon but also eat chum salmon in the fall. Studies are currently underway to identify Chinook salmon stocks that are particularly important to resident killer whales and to determine if resident killer whale populations are limited by the availability of Chinook salmon.
- Selective foraging by resident killer whales (Ford, J.K.B. and G.M. Ellis. 2006) (PDF)
- Prey selection and food sharing by resident killer whales (Ford, J.K.B, and G.M. Ellis. 2005) (PDF)
- Linking prey and population dynamics of resident killer whales (Ford, J.K.B., et al. 2005) (PDF)
- Dietary specialization in two sympatric populations of killer whale in coastal British Columbia and adjacent waters (Ford, J.K.B., et al. 1998) (PDF)
Remote Acoustic Monitoring
Remote underwater acoustic recording devices are useful to investigate killer whale occurrence in winter and spring. An “OrcaBox” has been deployed at Langara Island, Dixon Entrance, since 2003 and has successfully recorded killer whale vocalizations for four consecutive winters. More shore based and offshore acoustic devices are being deployed in other areas off the coast of British Columbia.
Identification of Critical Habitat
Critical habitat has been identified as Johnstone Strait for the northern resident killer whale population and Juan de Fuca Strait - Haro Strait – Georgia Basin for the southern resident population.
- Description of critical habitats for southern and northern resident killer whale populations (Species at Risk Act public registry)
- An assessment of critical habitats of resident killer whales in waters off the Pacific coast of Canada. (Ford, J.K.B. 2006) (PDF)
The diet of transient killer whales is studied in similar ways to resident killer whales, using behaviour observations, analyzing food remains from the stomachs of dead animals, scat analysis, and collecting prey remains left at kill sites. Unidentifiable prey remains are analyzed genetically to determine the species. Recent studies have reveled that harbour seals are the most important prey item, followed by harbour porpoises, Steller sea lions and Dall’s porpoises. Transients have also been seen preying upon Minke and grey whales.
- Fight or Flight: antipredator strategies of baleen whales (Ford, J.K.B. and R.R. Reeves. 2008) (PDF)
- Killer whale attacks on Minke whales (Ford, J.K.B. et al, 2005) (PDF)
Ongoing, long-term photographic identification studies have been used to estimate the population of West Coast transient killer whales. Photo identification data are also being used to study social structure and behaviour, life history, habitat use, and site fidelity. West Coast Transients are the only population known to frequent coastal waters of British Columbia. In 2007, their population was estimated to be about 250 whales. They can be seen any month of the year usually traveling close to shore in groups less than 10 individuals.
- Transient Killer Whales of British Columbia and Southeast Alaska Photo-Identification Catalogue 2008 (PDF 4MB)
- Recovery Potential Assessment for West Coast Transient Killer Whales (Ford, J.K.B., et al. 2007) (PDF)
Offshore killer whales are the least known of the three populations of killer whales in British Columbia waters because they are not often encountered. They are known to travel long distances and are observed more frequently off the outer coast. Photo identification techniques are used to monitor the population and have yielded a population estimate of fewer than 300 animals. The diet of offshore killer whales is not well understood. Offshore killer whales have been reported to feed on fish such as halibut, and recent analysis of prey remains has revealed they also feed on sharks. Skin biopsy samples are being examined to identify population structure, and acoustic monitoring is used to assess social structure.
- Management Plan (Species at Risk Act public registry)
Population MonitoringPhoto identification techniques and sightings collected during line transect surveys are used to study the abundance and distribution of humpback whales in British Columbia. Individual humpback whales can be identified by unique, natural markings on their tail flukes. Using these techniques, the population abundance of humpback whales in British Columbia in 2006 was estimated to be about 2100. Identification photographs taken over several sequential years can be used to determine social structure, population trends and abundance, site fidelity, and seasonal distribution. Line transect data collected simultaneously with hydro-acoustic data can be used to identify physical oceanographic features that may be important to humpback whales. Humpback whales migrate to British Columbia waters to feed and can be seen primarily from May to October. They show strong site fidelity, returning to the same feeding grounds each year. Comparing identification photographs has revealed that humpback whales feeding in northern British Columbia waters migrate primarily to the Hawaiian Islands in the winter and whales feeding in waters off southern Vancouver Island winter off mainland Mexico and Central America.
- Photo-identification catalogue of humpback whales in British Columbia (website)
- Recovery Potential assessment for BC Humpback whales (Ford, J.K.B., et al. In Press)
SPLASH: Structure of Populations, Levels of Abundance, and Status of Humpbacks
The Cetacean Research Program participated in an international collaborative research project to study humpback whales in the North Pacific during 2004 and 2005. The project’s objectives were to examine trends, abundance, movements, population structure and human impacts on humpback whales throughout the North Pacific. The SPLASH study identified almost 8000 unique individual whales through photographic identification and collected over 6000 tissue samples for genetic studies. This study estimated the abundance of humpback whales in the entire North Pacific to be approximately 20,000. To learn more about SPLASH please visit Cascadia Research Collective.
In collaboration with Cascadia Research Collective, identification photographs are taken and complied into a catalogue. By comparing photographs taken off the coast of British Columbia to photographs from other North Pacific regions we can learn about seasonal distribution, migratory destinations, and site fidelity. As well, line transect surveys provide information on abundance, and remote acoustic monitoring contributes information on distribution and seasonality. Blue whales seen off the coast of British Columbia are part of the eastern North Pacific population. The number of animals in this population is estimated to be about 2000. Their summer feeding grounds range from California to B.C. and Alaska.
Population Status and Distribution
To assess the abundance and distribution of large cetaceans, line transect surveys are conducted from large DFO Science vessels. Observers use high magnification binoculars (termed “Big Eyes”) to detect whales and identify the species. Whale distribution in relation to physical oceanographic features can be studied by simultaneously collecting hydro-acoustic and line-transect data. Identification photographs of large whales, including blue, fin, grey, and sperm whales, are collected in collaboration with other researchers to study distribution, site fidelity, and migratory destinations.
Remote Acoustic Monitoring
Submersible acoustic recording instruments digitally record low frequency vocalizations of large whales. These devices are moored in remote offshore waters for up to nine months. After retrieval, the acoustic data are analyzed and used to increase our understanding of the distribution and seasonality of large whales.
The Historical Whaling Database contains whaling catch records for British Columbia waters from 1908 to 1967. Records contain information on species, catch location and date, and biological details. For a detailed description of the B.C. Historical Whaling Database, refer to Nichol et al (2002) (PDF).
Determining Historical Abundance
Information on the number of whales harvested contained in the Historical Whaling Database is being used in ongoing assessments to determine historical abundance for many species of large whales.
Diet Analysis based on Stomach Contents
Prey remains from the stomachs of harvested whales from the Coal Harbour whaling station, in operation from 1948-1967, were documented by Gordon Pike, a DFO biologist at the Pacific Biological Station. This information can be used along with current prey analysis to study the diet of large whales.
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