Chapter 6: Marine Mammals - Cetaceans

• Main Authors: Pittman, SJ, Winship, AJ, Poti, M, Kinlan, BP, Leirness, JB, Baird, RW, Barlow, J, Becker, EA, Forney, KA, Hill, MC, Miller, PI, Mobley, J, Oleson, EM
• Other Authors: Costa, BM, Kendall, MS
• Format: Book Part
• Language: unknown
• Published: Bureau of Ocean Energy Management and National Oceanic and Atmospheric Administration 2016
• Subjects: Conservation; Earth Observation - Remote Sensing; Ecology and Environment; Marine Sciences; Oceanography; Planning; Policies; Humpback Whale; Megaptera novaeangliae
• Online Access: http://plymsea.ac.uk/id/eprint/7258/; http://www2.coastalscience.noaa.gov/publications/handler.aspx?key=9208

Marine mammals are ecologically, economically and culturally important to Hawaiʻi. Reliable information on species space-use patterns is required to inform marine spatial planning, particularly for offshore renewable energy installations. This chapter provides distribution maps for marine mammals observed in the U.S. waters of the Main Hawaiian Islands from 1993 to 2014 using data integrated from multiple sources and spatial predictive modeling. At least 26 species of marine mammal (one seal and 25 cetaceans) have been recorded across the project area, of which eight species are listed as Endangered. This chapter has two sections: 6.1 Cetaceans, and 6.2 Hawaiian monk seal. For cetaceans, maps are provided for 22 species, including 15 showing locations of sightings and seven showing predicted spatial distributions. Sighting data from aircraft, ships and small research vessels were integrated and modeled using non-linear algorithms to map summer and winter distributions. These models were based on the statistical relationships between cetacean abundance and environmental variables at the locations of sightings. Model performance ranged from 17 to 59 percent PDE (percentage deviance explained). Highest performing models were achieved for common bottlenose dolphin (Tursiops truncatus; 59% summer), spinner dolphin (Stenella longirostris; 56% winter) and humpback whale (Megaptera novaeangliae; 37% winter). All categories of predictors (survey platform, temporal, climatic, atmospheric, geographic, physical and biological oceanographic, and topographic), contributed to models, with depth, slope, surface current direction and the strengths of temperature and chlorophyll fronts being relatively important environmental predictors across models. For Hawaiian monk seal (Monachus schauinslandi), we provide maps of sighting locations, individual space-use patterns and the newly released critical habitat maps, followed by discussion of priorities for future data collection to support marine spatial planning.