Shore-based whale studies
Since 2001, the Hawai‘i Marine Mammal Consortium (HMMC) has conducted shore-based observations of humpback whales (Megaptera novaeangliae) from our research site, “Old Ruins”, located on the northwest coast of the Big Island, approximately 65 meters above sea level, overlooking Kawaihae Bay. Our research builds on that conducted by other research groups (that included Adam, Chris, Susan or Yin) in the 1980’s and 1990’s, using similar methodologies.
Though humpback whales are seen in Hawai‘i seasonally as early as October, we focus our shore-based research on the peak of the season, between early February and early March. During this period, we conduct scan observations once per day in one of four alternating time blocks (7-9 AM, 10 AM-12 noon, 1-3 PM, 4-6 PM) to approximate equivalent coverage of all daylight hours. The goal of each 15-minute scan is to document the presence and relative position of all marine mammals, vessels and aircraft. HMMC staff assume the roles of observer and theodolite operator, while students and volunteers rotate through the roles of computer operator and notetakers (including mapper). Whale and vessel locations are measured with a theodolite and 7x50 reticle binoculars with compass. A theodolite is a surveyor’s instrument that measures horizontal angles in relation to a fixed reference point, and vertical angles relative to gravity. At the touch of a few keystrokes, these angles are transferred to an Apple Macintosh laptop, running customized software developed by personnel at Cornell University.
Our scans add to a long-term database on the relative distribution, behavior and seasonal presence of humpback whales off the Kohala Coast. In addition to numerous humpback whales, we have observed spinner dolphins (Stenella longirostris), false killer whales (Pseudorca crassidens), bottlenose dolphins (Tursiops truncatus), and spotted dolphins (Stenella attenuata) from our shore-based research site in Kohala.
To learn more about our shore-based efforts, read the newsletters we’ve posted as well as our report (36 pages, 776 KB) to the Department of Land and Natural Resources, State of Hawai‘i and the Hawaiian Islands Humpback Whale National Marine Sanctuary on trends in shore-based whale observations 1988-2003.
In December 2005 at the Sixteenth Biennial Conference of the Society for Marine Mammalogy in San Diego, we presented a poster titled: Using compass and reticle binoculars to measure animal position: An evaluation and comparison to theodolite data, which is based on data from our shore station work. In 2009 we published a paper on this topic in Marine Mammal Science