Cetacean Survey of Windward Moloka‘i Waters

Marie Hill, Erin Oleson, Amanda Bradford, Erik Norris, Ali Bayless, Yvonne Barkley- PIFSC Cetacean Research Program; Ed Lyman and Joe Carrier- Hawaiian Islands Humpback Whale National Marine Sanctuary; Daniel Webster- Cascadia Research Collective; Allan Ligon- PIFSC Contractor

Kalaupapa National Historical Park is located on the Kalaupapa Peninsula on the north shore of the island of Molokai.  Surrounded by ocean on three sides and cut off from the rest of Molokai by 1600-foot cliffs, Kalaupapa is considered one of the most remote places in the main Hawaiian Islands.  As a result of this detachment from the outside world, Kalaupapa boasts an abundance of terrestrial and marine resources.  The Pacific Islands Fisheries Science Center Cetacean Research Program (PIFSC CRP), in collaboration with the National Park Service, the Hawaiian Islands Humpback Whale National Marine Sanctuary, and Cascadia Research Collective, conducted two weeks of cetacean surveys off the north coast of Moloka‘i while based out of Kalaupapa.

The windward side of Molokai and Maui have not been intensively surveyed for cetaceans, such that most information about species distribution comes from one or two ship surveys with sparse coverage of the area, from occasional reports from other researchers or fishermen, or from animals that were satellite tagged in leeward waters, but used this area while tagged. The primary goals of this collaborative survey effort were to collect photographs and biopsy samples and deploy satellite tags on a variety of cetacean species to assess windward versus leeward movements and population structure.  A High-frequency Acoustic Recording Package (HARP) was also deployed to record vocalizing cetaceans in the area during our survey.

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Marie Hill scanning the water for cetaceans off the north shore of Moloka‘’i. Photo by Ali Bayless.

The primary target species for this study was Pseudorca crassidens, commonly known as the false killer whale, a large toothed whale that is found in temperate and tropical waters throughout the world.  Based on satellite tag data from Cascadia Research Collective, an area north of Moloka‘i and Maui has been identified as a “hotspot” of the Endangered main Hawaiian Islands (MHI) insular population of false killer whales.  We were particularly interested in finding individuals from one of the three social groups (often referred to as clusters) that are less frequently encountered and have never been successfully satellite tagged.

The collection of telemetry data from two of the three social clusters of MHI insular false killer whales tagged off leeward Hawai‘i and O‘ahu indicate an area of particularly high use off the north side of Moloka‘i and Maui. Figure copied from Baird et al. (2012).

The collection of telemetry data from two of the three social clusters of MHI insular false killer whales tagged off leeward Hawai‘i and O‘ahu indicate an area of particularly high use off the north side of Moloka‘i and Maui. Figure copied from Baird et al. (2012).

The surveys were conducted 24 August – 5 September 2014, during which a total of 1,092 km of trackline was surveyed in northern Moloka‘i waters. For most of the survey days, moderate to strong trade winds prevailed, producing Beaufort 4 to 6 sea states. In addition, during the first week of surveys we received some moderate swells produced by hurricane Marie in the Eastern Pacific. These sea conditions made both finding animals and working with them challenging. We had 1 encounter with Blainville’s beaked whales (Mesoplodon densirostris), 1 encounter with short-finned pilot whales (Globicephala macrorhynchus), 2 encounters with unidentified beaked whales (1 was a probable Blainville’s), and 2 encounters with unidentified odontocetes (1 was a “blackfish”; possibly a false killer whale). We collected 1,003 photos. Individuals photographed during the Blainville’s beaked whale and the short-finned pilot whale encounters will be compared to existing photo-identification catalogs at Cascadia Research Collective.  We successfully retrieved the HARP and are very interested to know what cetacean vocalizations it picked up.  The sounds produced by false killer whale and certain other cetacean species are well-characterized and will be easily picked out if they were recorded on the HARP.

Map of survey effort in Moloka‘i waters.  The green lines are the survey tracks.  The white line outlines the highest use area of the false killer whale “hot spot.”  Circles indicate sighting locations: BB = Blainville’s beaked whale, PW = pilot whale, UB = unidentified beaked whale, UD = unidentified large dolphin (“blackfish”), and UO = unidentified odontocete.  The telephone symbol shows the position of the HARP.

Map of survey effort in Moloka‘i waters. The green lines are the survey tracks. The white line outlines the highest use area of the false killer whale “hot spot.” Circles indicate sighting locations: BB = Blainville’s beaked whale, PW = pilot whale, UB = unidentified beaked whale, UD = unidentified large dolphin (“blackfish”), and UO = unidentified odontocete. The telephone symbol shows the position of the HARP.

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Blainville’s beaked whale mother and calf (upper panel) and pilot whales (lower panel) sighted off the northern coast of Moloka‘i. Photos by Amanda Bradford.

This project could not have been accomplished without the support of multiple entities.  The project was funded by PIFSC, the NMFS Office of Science and Technology, and the Pacific Islands Regional Office. The Hawaiian Islands Humpback Whale National Marine Sanctuary provided the vessel and staff.  The Koholā is an 11-meter  Ambar Marine Silver Ships vessel specifically designed for large whale entanglement response and research and proved to be a versatile and effective platform for this work and exceptionally well-suited for the challenging conditions we encountered during our survey.

Koholā moored just off the Kalaupapa settlement. Photo by Ed Lyman.

Koholā moored just off the Kalaupapa settlement. Photo by Ed Lyman.

Cascadia Research Collective provided tagging expertise and some of the tagging deployment equipment, as well as photo-identification catalogs and associated data of known individuals for our reference.  The National Park Service (NPS) provided an enormous amount of logistical support, both on and off the water. The NPS staff were instrumental in organizing field operations, assisting in everything from equipment transportation and storage to housing arrangements and fueling of the vessel.  Some of the NPS employees joined us on the water to assist in the survey and get a first-hand look at the research being conducted.  This unique collaboration is a great example of what can be accomplished when multiple entities come together to work towards a common goal, and we all hope to work together again in the future.

Collage of Molokai survey team members. Upper left, from left to right: Sarah Allan (NPS), Allan Ligon (PIFSC contractor), Ali Bayless (CRP-JIMAR), Marie Hill (CRP-JIMAR), Joe Carrier (NOAA Corps-HIHWNMS), and Erik Norris (NOAA Corps-CRP); photo by Sly Lee.  Upper right, clockwise: Marie, Daniel Webster (CRC), Erik, Allan, and Yvonne Barkley (CRP-JIMAR); photo by Amanda Bradford.  Lower left, clockwise: Allan, Petra Bertilsson (NPS), Ed Lyman (HIHWNMS), Erik, Daniel, and Erin Oleson (CRP); photo by Amanda Bradford.  Lower right, from left to right: Erik and Amanda Bradford (CRP); photo by Ed Lyman.

Collage of Molokai survey team members. Upper left, from left to right: Sarah Allan (NPS), Allan Ligon (PIFSC contractor), Ali Bayless (CRP-JIMAR), Marie Hill (CRP-JIMAR), Joe Carrier (NOAA Corps-HIHWNMS), and Erik Norris (NOAA Corps-CRP); photo by Sly Lee. Upper right, clockwise: Marie, Daniel Webster (CRC), Erik, Allan, and Yvonne Barkley (CRP-JIMAR); photo by Amanda Bradford. Lower left, clockwise: Allan, Petra Bertilsson (NPS), Ed Lyman (HIHWNMS), Erik, Daniel, and Erin Oleson (CRP); photo by Amanda Bradford. Lower right, from left to right: Erik and Amanda Bradford (CRP); photo by Ed Lyman.

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