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Two species of sea lions occur in the inland waters of Washington State: the California sea lion (Zalophus californianus) and the Steller sea lion (Eumetopias jubatus). Both species breed elsewhere, but they typically move into Puget Sound and adjacent waters of the Salish Sea from autumn through spring. There is a need for information on their current abundance and seasonal use patterns as both species prey heavily on threatened/ endangered stocks of salmon and steelhead trout (Oncorhynchus spp.), and empirical abundance estimates of these species are lacking for inland Washington waters. From 2013 to 2016, we conducted 39,399 km of aerial surveys for marine mammals in this area, sighting 255 groups of sea lions. We used a subset of 7,841 km of effort and 165 sea lion sightings made during surveys in good sighting conditions to estimate in-water abundance using line-transect methods. Historical tagging data collected in Pacific Northwest waters were used to evaluate the proportions of time that each species spent on land and conducting dives, and then to develop correction factors to derive total abundance for both sea lion species, providing the first empirical abundance estimates for these waters. We estimated that between 33 and 442 California sea lions were found in Puget Sound/ Hood Canal in different seasons, with nearly 3,000 being found in the broader inland Washington waters in the peak season (spring). Steller sea lions occurred in much smaller numbers, with a peak of 219 animals in Puget Sound/Hood Canal/Strait of Juan de Fuca in autumn (and possibly as many as 600 to 700 in the entire study area). While some estimates suffer from low precision, this study demonstrates that substantial numbers of sea lions use waters of the study area throughout much of the year. Our results provide an important step toward a better understanding of these two species in the inland waters of Washington, as well as their potential effects on protected salmonid prey species. [ABSTRACT FROM AUTHOR]

The United States Exploring Expedition of 1838–1842, in some ways, represents the beginning of American marine mammal biology. The expedition returned home with information on at least twelve marine mammal specimens (mostly small cetaceans or pinnipeds), seven of which were considered new species at the time. Commanded by Lieutenant Charles Wilkes, the expedition covered over 80,000 miles, surveyed new waters and lands, and brought back thousands of scientific specimens. Official publications of the expedition by Titian Peale and John Cassin cover the birds and mammals collected. The squadron's publications, and the journals of its officers and scientists also contain a good deal of information about sightings of marine mammals. Of particular interest were whaling operations and grounds, and the expedition did much to help expand the whaling prospects of the United States around the globe, with a focus on the South Pacific islands. Though largely forgotten today, the "U. S. Ex. Ex." played an important early role in establishing American influence in marine mammal biology and global whaling operations. [ABSTRACT FROM AUTHOR]

The title of Perrin's presentation was, "The problem of porpoise [= dolphin] mortality in the U. S. tropical tuna fishery" (Perrin, [5]). Bill invited Louella the following year to attend the IWC gill net meeting in La Jolla in 1991 (Perrin et al., [15]) where she presented the bycatch data she gathered from gill net fisheries in the Philippines. Besides being the first person to alert the world to the massive kills of dolphins that were happening in the eastern tropical Pacific tuna fishery in the 1960s, decades later Bill created a compilation of the thousands of documents related to the controversy, along with a searchable bibliography (Perrin, [9]). Bill's critical early research on oceanic dolphins brought world attention to the longstanding and growing problem of incidental mortality of cetaceans in fisheries, but it was also transformative given the huge and enduring impact it had on cetacean science. [Extracted from the article]

The inland waters of Washington State are inhabited regularly by 10 species of marine mammals. Updated and comprehensive information regarding marine mammal occurrence, distribution, and behavior in the area is critical when addressing local anthropogenic impact, management, and conservation concerns. We conducted a total of 16,198 km of observation effort during systematic line-transect surveys from a high-wing, twin-engine airplane throughout Puget Sound in all 4 seasons during 2013 to 2016, and in the Strait of Juan de Fuca and San Juan Islands area during summer 2014 and spring 2015. Ten marine mammal species were confirmed across 5772 groups of an estimated 10,673 individuals sighted, including some seasonal patterns of occurrence. The most commonly sighted species in terms of individuals were Harbor Seals (n = 8012), Harbor Porpoises (n = 2168), California Sea Lions (n = 238) and Steller Sea Lions (n = 77). The most common behavior states documented across species among the total 5670 groups were rest (73%) and medium travel (16%); probable foraging was observed among 13 groups (0.2%) and included Gray Whale foraging pits in tidal mudflats. Potential behavioral reactions to the aircraft were rare (0.3% of total individuals), primarily by Harbor Seals and Harbor Porpoises. Results of these surveys represent the most comprehensive up-to-date information available on marine mammal occurrence, distribution, and behavior across seasons in the Puget Sound region. [ABSTRACT FROM AUTHOR]

The estuaries and tidal rivers of the Gulf of Maine have rarely been surveyed systematically for marine mammals. We report here on three years of survey data, 2017 to 2019. This study employed a shipboard visual line-transect methodology study design, collecting data on marine mammals in the lower Piscataqua River, which is confluent with the Gulf of Maine. Marine mammal species observed most often were harbor seals (Phoca vitulina) and gray seals (Halichoerus grypus), with a resulting in-water density estimate of 1.02 seals/km2 and an abundance estimate of seven harbor seals and one gray seal (CV = 19.3%) in the survey area. Seals were present in all months of the year. No live pups were detected. Harbor porpoises (Phocoena pho-coena) and minke whales (Balaenoptera acuto-rostrata) were also observed, but the sightings (6 harbor porpoises; 7 minke whales) did not yield enough data to estimate density or abundance. The minke whales were present during August and September 2018, concurrent with an influx of Atlantic menhaden (Brevoortia tyrannus), a prey species. The consistent albeit relatively low marine mammal species sightings and abundances suggest that the lower Piscataqua River is used regularly by a relatively small number of harbor and gray seals, although not for pupping, and occasionally by harbor porpoises and by foraging minke whales. This is the first study of its kind in an estuarine environment in the Gulf of Maine. [ABSTRACT FROM AUTHOR]