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NMFS PIFSC Technical Memorandum ; 72

PIFSC data report ; DR-18-002

The Pacific Islands Fisheries Science Center's (PIFSC) Cetacean Research Program (CRP) has been conducting visual surveys for cetaceans in the waters surrounding Guam and the Commonwealth of the Northern Mariana Islands (CNMI) as part of an ongoing effort to develop a record of cetacean occurrence in the region. Visual surveys have been conducted aboard small boats (7.6--12.2 m) since 2010 off the southernmost islands of the Mariana Archipelago (Guam, Rota, Saipan, Tinian, and Aguijan). These surveys include the collection of photographs for individual identification, tissue samples for genetic analysis of population structure, and the deployment of satellite tags for assessment of individual movements throughout the broader region. These surveys are conducted in partnership with the Commander, U.S. Pacific Fleet Environmental Readiness Division, which is mandated by Letters of Authorization and Biological Opinions issued under the Marine Mammal Protection Act (MMPA) and the Endangered Species Act (ESA) to monitor cetaceans within the Mariana Islands Training and Testing (MITT) study area. Data sets from the small-boat survey efforts are used to evaluate the distribution, stock structure, and movements of cetaceans within the study area. This report includes a summary of the most recent visual surveys that were conducted in the 'winter' (March) and 'summer' (MayJune) of 2016.

This report includes a summary of the most recent visual surveys that were conducted in the winter (February–March) and summer (August–September) of 2015, the movements of a false killer whale (Pseudorca crassidens) that were satellite tagged during the PIFSC Mariana Archipelago Cetacean Survey in May–June, 2015, the results of nuclear and mitochondrial analysis of short-finned pilot whale samples collected during small-boat surveys of the southernmost Mariana islands (2011–2014), and analysis of beaked whale occurrence long-term passive acoustic data set for 2014–15. Analyses of acoustic data for baleen whales are still underway and will be reported at a later time.

The Pacific Islands Fisheries Science Center’s (PIFSC) Cetacean Research Program (CRP) has been conducting visual surveys for cetaceans in the waters surrounding Guam and the Commonwealth of the Northern Mariana Islands (CNMI) and collecting long-term passive acoustic monitoring data at two sites in CNMI as part of an ongoing effort to develop a record of cetacean occurrence in the region. Visual surveys, conducted aboard small boats (7.6 – 12.2 m), have been ongoing since 2010 off the southern Mariana Islands of Guam, Rota, Saipan, Tinian, and Aguijan (Figure 1). These surveys include the collection of photographs for individual identification, tissue samples for genetic analysis of population structure, and the deployment of satellite tags for assessment of individual movements through the broader region. These surveys have been carried out in partnership with the Commander, U.S. Pacific Fleet Environmental Readiness Division. PIFSC has also maintained long-term acoustic monitoring sites in CNMI since 2010. The various datasets from these efforts are collectively being used to evaluate the seasonal occurrence and distribution, stock structure, and movements of cetaceans within the study area. This report includes a summary of the most recent survey, updates on the status of existing photo-identification catalogs and the creation of new photo-identification catalogs, and summaries of genetic analyses of bottlenose dolphin (Tursiops truncatus) and short-finned pilot whale (Globicephala macrorhynchus) samples collected in the region, preliminary interpretation of satellite telemetry datasets, and the year-round occurrence of cetacean sounds recorded. The Appendices contain the more detailed reports on the mitochondrial and nuclear DNA analyses of bottlenose dolphins and short-finned pilot whales sampled in the Mariana Islands.

Due to U.S. territorial status, management of marine mammal stocks around Guam and the CNMI is the responsibility of the U.S. National Marine Fisheries Service. The U.S. Navy is mandated by permits and Biological Opinions issued under the Marine Mammal Protection Act (MMPA) and the Endangered Species Act (ESA) to monitor cetacean presence within the Mariana Island Range Complex (MIRC). The ocean surface and undersea area components of the MIRC encompass 1,299,851 km of open ocean and coastal areas that extend from the international waters south of Guam to north of Pagan (CNMI), and from the Pacific Ocean east of the Mariana Islands and west to the middle of the Philippine Sea (U.S. Navy 2010). Within the MIRC, the Navy is authorized to conduct training and testing activities, which may include the use of active sonar, underwater detonations, and explosive ordnance use. Such activities have the potential to harass or harm cetaceans...In an effort to further develop a record of cetacean occurrence in the region, as well as to gather photos and biopsy samples and deploy satellite tags for population studies, the Pacific Islands Fisheries Science Center’s (PIFSC) Cetacean Research Program (CRP) conducted surveys for cetaceans in the waters surrounding Guam and the CNMI (Figure 1) during 2010-2014. This research was carried out in partnership with the U.S. Navy and is expected to continue through 2015. Detailed reports for each survey year were submitted to the Navy (Oleson and Hill 2010, Ligon et al. 2011, Hill et al. 2012, Hill et al. 2013). The summary of the combined surveys is reported here.