The harbor porpoise (Phocoena phocoena (L., 1758)) used to be common in Puget Sound, Washington, but virtually disappeared from these waters by the 1970s. We conducted systematic aerial line-transect surveys (17 237 km total effort) for harbor porpoises, with the goal of estimating density and abundance in the inland waters of Washington State. Surveys in Puget Sound occurred throughout the year from 2013 to 2015, and in the Strait of Juan de Fuca and the San Juan Islands (and some adjacent Canadian waters) in April 2015. We used a high-wing, twin-engine Partenavia airplane and four observers (one on each side of the plane, one looking through a belly port, and one recording data). A total of 1063 harbor porpoise groups were sighted. Density and abundance were estimated using conventional distance sampling methods. Analyses were limited to 447 harbor porpoise groups observed during 5708 km of effort during good sighting conditions suitable for line-transect analysis. Harbor porpoises occurred in all regions of the study area, with highest densities around the San Juan Islands and in northern Puget Sound. Overall, estimated abundance for the Washington Inland Waters stock was 11 233 porpoises (CV = 37%, 95% CI = 9 616 – 13 120). This project clearly demonstrated that harbor porpoises have reoccupied waters of Puget Sound and are present there in all seasons. However, the specific reasons for their initial decline and subsequent recovery remain uncertain.

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Kealakekua Bay is an important resting site for Hawaiian spinner dolphins (Stenella longirostris) and is popular with both local residents and tourists. Human activities occurring here include swimming, snorkeling, kayaking, and motor-boating. The objectives of this study were to document movement patterns of dolphin groups in Kealakekua Bay, to determine if different types and levels of human activity within the bay result in quantifiable changes in dolphin group movement patterns, and to provide baseline data for future studies. Theodolite tracking was used to assess responses of dolphin groups to human traffic. Variables examined included group mean leg speed (leg speed: the distance between two consecutive theodolite fixes of a dolphin group divided by time; mean leg speed: the average of all leg speeds comprising a track) and group reorientation rate. Swimmers and/or vessels were present within 100 m of all dolphin groups tracked during all surveys. Regression analyses were used to examine potential relationships between dolphin group related variables (e.g., reorientation rate, mean leg speed) and variables related to human activities (e.g., swimming, kayaking, motor-boating). Increasing levels of human activity had a limited but measurable effect on the movement patterns of Hawaiian spinner dolphin groups at this site.

Questions have been raised about the effects human activity in Hawai'ian bays has on dolphins. Concerns about the effects of this activity have led the National Marine Fisheries Service to begin the process of enacting regulations to reduce the impacts of swimmers and vessels on Hawaiian spinner dolphins (Stenella longirostris). One step in evaluating potential effects is to determine if dolphin presence attracts swimmers and vessels into bays. In this study, numbers of vessels and swimmers in Kealake'akua, Honaunau, and Kauhako Bays were measured and related to spinner dolphin presence. In Kauhako Bay, mean number of swimmers per scan sample was significantly higher when dolphins were present, and in Honaunau Bay, mean number of kayaks per scan sample was significantly higher when dolphins were present. In addition to measuring the relationship between dolphin presence and vessel and swimmer presence, it is important to track vessel and swimmer numbers over time and to determine patterns of use in individual bays. This establishes trends in human use of bays and allows management on a more individual bay basis. During this study, Kealake'akua Bay experienced significantly more vessel and swimmer activity than Kauhako Bay. Numbers of one-to three-person kayaks, motorboats <6 m, and zodiacs were highest in Kealake'akua Bay. Numbers of swimmers from shore were higher in Honaunau Bay than in Kauhako Bay. Overall, numbers of vessels and swimmers in the bays were higher than in previous decades, and swimmers comprised the majority human activity in the bays.

The Florida manatee (Trichechus manatus latirostris)i so ne of the most endangered marine mammals in the US To protect this species, it is important to understand the feeding ecology to define critical habitats. Manatees generally are considered to be strictly herbivious mammals that only incidentally consume animal species. This concept is based on the preponderence of freshwater vegetation, seagrasses, and algae that is found in most stomach content and fecal analyses. In the present study, manatees were observed feeding in areas of the Indian River Lagoon in Vero Beach and Fort Pierce, Florida, USA during June to August 2001. Most manatees were observed to be feeding on seagrasses and algae; however, on two occasions, manatees were observed apparently preferentially consuming invertebrates that were attached to ad ock. Although some fibrous algae were present on the dock structure, the majority of biomass present was made up of invertebrates. Manatees were heard crunching invertebrate shells and seen pulling animals, such as tunicates, into their mouths. These observations suggest that manatees actively, rather than incidentally, consume invertebrates in some cases.