Sally A. Mizroch

Alaska marine mammal stock assessments, 2009

NOTE – March 2008: In areas outside of Alaska, studies have shown that stock structure is more fine-scale than is reflected in the Alaska Stock Assessment Reports. At this time, no data are available to reflect stock structure for harbor porpoise in Alaska. However, based on comparisons with other regions, smaller stocks are likely. Should new information on harbor porpoise stocks become available, the harbor porpoise Stock Assessment Reports will be updated.

Alaska marine mammal stock assessments, 2006

STOCK DEFINITION AND GEOGRAPHIC RANGE The humpback whale is distributed worldwide in all ocean basins. In winter, most humpback whales occur in the subtropical and tropical waters of the Northern and Southern Hemispheres. Humpback whales in the high latitudes of the North Pacific are seasonal migrants that feed on euphausiids and small schooling fishes (Nemoto 1957; 1959, Clapham and Mead 1999). The humpback whale population was considerably reduced as a result of intensive commercial exploitation during the 20 century. A large-scale study of humpback whales throughout the North Pacific was conducted in 2004-06 (the Structure of Populations, Levels of Abundance, and Status of Humpbacks, or SPLASH, project). Initial results from this project (Calambokidis et al. 2008), including abundance estimates and movement information, are used in this report. Genetic results, which may provide a more comprehensive understanding of humpback whale population structure in the North Pacific, should be available in the near future. Figure 38. Approximate distribution of humpback whales in the western North Pacific (shaded area). Feeding and wintering grounds are presented above (see text). Area within the hash lines is a probable distribution area based on sightings in the Beaufort Sea. See Figure 39 for humpback whale distribution in the eastern North Pacific.

Alaska marine mammal stock assessments, 2002

STOCK DEFINITION AND GEOGRAPHIC RANGE Steller sea lions range along the North Pacific Rim from northern Japan to California (Loughlin et al. 1984), with centers of abundance and distribution in the Gulf of Alaska and Aleutian Islands, respectively. The species is not known to migrate, but individuals disperse widely outside of the breeding season (late May-early July), thus potentially intermixing with animals from other areas. Despite the wide-ranging movements of juveniles and adult males in particular, exchange between rookeries by breeding adult females and males (other than between adjoining rookeries) appears low (NMFS 1995). Loughlin (1997) considered the following information when classifying stock structure based on the phylogeographic approach of Dizon et al. (1992): 1) Distributional data: geographic distribution continuous, yet a high degree of natal site fidelity and low (<10%) exchange rate of breeding animals between rookeries; 2) Population response data: substantial differences in population dynamics (York et al. 1996); 3) Phenotypic data: unknown; and 4) Genotypic data: substantial differences in Figure 1. Approximate distribution of Steller sea lions in the North Pacific. Major U.S. haulouts and rookeries (50 CFR 226.202, 27 August 1993) and active Asian haulouts and rookeries (Burkanov and Loughlin, 2005) are depicted (points). Black dashed line (144° W) indicates stock boundary (Loughlin 1997). Note: Haulouts and rookeries in British Columbia are not shown.

Alaska marine mammal stock assessments, 2015

NOTE – NMFS is in the process of reviewing humpback whale stock structure under the Marine Mammal Protection Act (MMPA) in light of the 14 Distinct Population Segments established under the Endangered Species Act (ESA) (81 FR 62259, 8 September 2016). A complete revision of the humpback whale stock assessments will be postponed until this review is complete. In the interim, new information on humpback whale mortality and serious injury is provided within this report.

Beluga whale, Delphinapterus leucas, satellite-tagging and health assessments in Cook Inlet, Alaska, 1999 to 2002

Cook Inlet beluga whales, Delphinapterus leucas, are currently listed as ‘Endangered’ under the U.S. Endangered Species Act (ESA). The National Marine Fisheries Service (NMFS) began monitoring this population during the 1990s after it was added to the ESA Candidate Species list in 1988. Monitoring efforts included aerial surveys, and in 1995, the first attempts to capture and satellite-tag whales. Working with Canadian scientists and Alaska Native subsistence hunters in 1995 and 1997, tagging methods were adapted to conditions in Cook Inlet (muddy water, extreme tides, and extensive mudflats), culminating in successful capture and tracking of a whale during the summer of 1999. This was followed by three more years of capture and tagging studies during late summer. Tags were attached to 18 whales between 1999 and 2002. We do not have detailed accounts of these later tagging seasons (e.g., similar to the Appendix chronicling events from the 1997 and 1999 seasons in Ferrero et al. (2000)). Litzky et al. (2001) summarized field operations for the 2000 tagging season, but no reports exist for 2001 and 2002. A reanalysis of the tag dataset (Goetz et al. 2012) led to questions about the captures and how tags were programmed during this time period. Given the Cook Inlet population has continued to decline (Hobbs et al. 2015, Shelden et al. 2017), and was listed as an Endangered Distinct Population Segment under the ESA in October 2008 (NOAA 2008), future recommendations for tagging will depend on lessons learned from these past projects. Lacking detailed field reports, we consolidated information from multiple sources. Herein, we bring these varied sources together to provide a thorough documentation of the tagging operations undertaken in Cook Inlet each summer in 2000, 2001, and 2002. We include revised tag transmission timelines, monthly movement maps, dive behavior data, and ice-association graphs and maps for all whales (where applicable) tagged in 1999, 2000, 2001, and 2002. Whale locations were compared to sighting records (opportunistic and systematic) to determine how many whales were likely proximate to tagged whales. Animations of whale movements are available at http://www.afsc.noaa.gov/News/Cook_Inlet_Beluga_Range_Contracted.htm (accessed 17 Aug. 2016).