Great Whale Count


Project Name: The Great Whale Count

Project Dates: Ongoing

Project Site(s): Twelve coastal sites along the southern and western shores of the island of Maui, in an area extending from Makena to Kapalua. The last site is located at Hookipa Beach Park on Maui’s north shore. All sites, except Hookipa, are situated within the Hawaiian Islands Humpback Whale National Marine Sanctuary.

Project Aims: Using citizen science to engage members of the public and promote environmental stewardship, while contributing toward a long-term humpback whale sighting dataset.

Project Justification: This study’s primary objective is to provide an updated and accurate trend of humpback whale sightings for Maui coastal waters. Monitoring the Hawaiian humpback whale population is important because of its endangered status (U.S. Endangered Species Act, 1972) and its support of a thriving whale watching industry.

Project Methodology: This study consists of one day of point-counts each year conducted simultaneously from multiple coastal sites along the southern shores of the island of Maui. The count takes place annually between January 31st and March 11th, which generally coincides with the peak of the breeding and calving season. Sites are monitored by teams of observers consisting of a site leader and a group of volunteers.

Teams perform scans within concurrent 20-minute intervals between 0830 and 1200. During the first 10 minutes, observers report all sightings of humpback whales within the survey area (three nautical mile radius from each site). During each scan, number of pods, individuals in each group, presence of calves, distance and compass bearing to each pod are noted. Environmental conditions are also recorded including sea state, glare percentage, as well as wind speed and direction. Immediately following this scan, observers devote five minutes to recording conspicuous behaviors (e.g. breaches, pectoral fin slaps, tail slaps, and peduncle throws). Observers rest for the remaining five minutes before the next 10-minute scan.

Please note that the Great Whale Count does not aim at calculating a population estimate but rather a proportion of humpback whales within three miles from shore. In addition, sites are situated three miles apart to ensure that there is no overlap between them.

Project Permits and/or Collaborators: No permit required given that the humpback whales are observed from shore.

Management Outcomes: Citizen science is becoming a widespread tool for ecological and environmental monitoring, especially in an era of fiscal restraint by governments and NGOs. Not only can citizen science engage members of the public and promote environmental stewardship, but the data can be useful in ecosystem monitoring and assessment. The Great Whale Count data indicate an overall upward trend in the number of whales sighted since 1995, with a 5.2% increase of humpback whale sightings per year in the Maui coastal waters. These results correlate with other scientific studies, indicating a steadily increase of the population of North Pacific Humpback Whales.

Publications/Presentations: Tonachella et al. (in press). Predicting trends in humpback whale abundance using citizen science. Pacific Conservation Biology.

GWC final count over the past years: 








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