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Pacific salmon (Oncorhynchus spp.) are important to the ecology, economy, and cultures of the Pacific Northwest. Many populations of Pacific salmon in the Pacific Northwest are declining because of poor marine survival. We evaluated the role of Steller (Eumetopias jubatus) and California (Zalophus californianus) sea lions as predators of Pacific salmon. Roughly, half of the 1330 metric tons (t) of Pacific salmon eaten by Steller sea lions per year and of the 1220 t of Pacific salmon eaten by California sea lions per year in northwest Washington during 2010-2013 were coho salmon (O. kisutch). The response of Steller and California sea lions to the large run of pink salmon (O. gorbuscha) in 2011 was less than expected. Sea lions of these species rarely ate large (roughly ≥50 cm in total length) Chinook salmon (O. tshawytscha), indicating that they have limited direct competition for prey with the southern resident distinct population segment of killer whales (Orcinus orca). Combined, California and Steller sea lions in northwest Washington consumed a mass of coho salmon similar to that landed by commercial fisheries in Washington State. More work on modeling the effect of the predation by California and Steller sea lions on salmon populations, particularly for coho salmon, is needed to better evaluate the conservation and productivity of Pacific salmon. [ABSTRACT FROM AUTHOR]

Preseason abundance forecasts drive management of US West Coast salmon fisheries, yet little is known about how environmental variability influences forecast performance. We compared forecasts of Chinook salmon (Oncorhynchus tshawytscha) against returns for (i) key California-Oregon ocean fishery stocks and (ii) high priority prey stocks for endangered Southern Resident Killer Whales (Orcinus orca) in Puget Sound, Washington. We explored how well environmental indices (at multiple locations and time lags) explained performance of forecasts based on different methods (i.e. sibling-based, production-based, environment-based, or recent averages), testing for nonlinear threshold dynamics. For the California stocks, no index tested explained >50% of the variation in forecast performance, but spring Pacific Decadal Oscillation and winter North Pacific Index during the year of return explained >40% of the variation for the sibling-based Sacramento Fall Chinook forecast, with nonlinearity and apparent thresholds. This suggests that oceanic conditions experienced by adults (after younger siblings returned) have the most impact on sibling-based forecasts. For Puget Sound stocks, we detected nonlinear/threshold relationships explaining >50% of the variation with multiple indices and lags. Environmental influences on preseason forecasts may create biases that render salmon fisheries management more or less conservative, and therefore could motivate the development of ecosystem-based risk assessments. [ABSTRACT FROM AUTHOR]

From December to February in most years from 1967 to 2007, observers counted gray whales, Eschrichtius robustus, from shore sites south of Carmel in central California. In addition to gray whales, other cetacean species were also recorded. These observations were summarized and compared among survey platforms and to ocean conditions. Eleven cetacean species were identified including eight odontocete species (killer whale, Orcinus orca; Pacific white-sided dolphin, Lagenorhynchus obliquidens; common dolphin, Delphinus spp.; bottle-nose dolphin, Tursiops truncatus, northern right whale dolphin, Lissodelphis borealis; Risso's dolphin, Grampus griseus; Dall's porpoise, Phocoenoides dalli; and harbor porpoise, Phocoena phocoena) and three mnysticete species (humpback whale, Megaptera novaeangliae: minke whale, Balaenoptera acutorostrata; and blue whale, Balaenoptera musculus). As expected, the detection of certain species among survey platforms (shore-based census watches, 25-power "Big Eye" binocular watches, and aerial surveys) was limited by species surfacing behavior and/or bathymnetric preference. Comparisons among the shore-based census efforts showed a significant difference in sightings rates from 1967-84 (n = 14, mean = 0.11, SD = 0.11) to 1985-2007 (n = 11, mean = 1.48, SD = 0.47; t-Test: p < 0.001, df = 23). The warm period observed during the 1990's may partially explain the increase in sighting rates and diversity of species observed at the census site compared to the much cooler temperatures of the 1970's. [ABSTRACT FROM AUTHOR]

Abstract: “Southern Resident” killer whales (Orcinus orca) that comprise three fish-eating “pods” (J, K and L) were listed as “endangered” in the US and Canada following a 20% population decline between 1996 and 2001. Blubber biopsy samples from Southern Resident juveniles had statistically higher concentrations of certain persistent organic pollutants than were found for adults. Most Southern Resident killer whales, including the four juveniles, exceeded the health-effects threshold for total PCBs in marine mammal blubber. Maternal transfer of contaminants to the juveniles during rapid development of their biological systems may put these young whales at greater risk than adults for adverse health effects (e.g., immune and endocrine system dysfunction). Pollutant ratios and field observations established that two of the pods (K- and L-pod) travel to California to forage. Nitrogen stable isotope values, supported by field observations, indicated possible changes in the diet of L-pod over the last decade. [Copyright &y& Elsevier]

The article studies the food habits of killer whales (Orcinus orca) and the effect of changes of feeding, on marine Eco system. Jim Estes of the University of California, Santa Cruz, suggests that the disappearance sea otters caused a boom of sea urchins, thereby destroying large areas of kelp forest. The article also presents arguments of marine biologists including Alan Springer and Paul Wade on Orcinus orca and their marine feeds.

Despite their limited area relative to the global ocean, coastal zones-the regions where land meets the sea-play a disproportionately important role in generating ecosystem services. However, coastal ecosystems are under increasing pressure from human populations. In particular, urban stormwater is an increasingly important threat to the integrity of coastal systems. Urban catchments exhibit altered flow regimes that impact ecosystem processes and coastal foodwebs. In addition, urban stormwater contains complex and unpredictable mixtures of chemicals that result in a multitude of lethal and sublethal impacts on species in coastal systems. Along the western coast of the United States, we estimate that hundreds of billions of kilograms of suspended solids flow off land surfaces and enter the Northern California Current each year. However, 70% of this pollution could be addressed by treating only 1.35% of the land area. Determining how to prioritize treatment of stormwater in this region requires a clear articulation of objectives-spatial distribution of appropriate management actions is dependent on the life histories of species, and management schemes optimized for one species may not achieve desired objectives for other species. In particular, we highlight that the scale of stormwater interventions must match the ecological scale relevant to species targeted by management. In many cases, management and policy will require mechanisms in order to ensure that local actions scale-up to efficiently and effectively achieve management objectives. In the face of rapid urbanization of coastal zones, failure to consider the match of management and ecological scales will result in the continued decline of coastal ecosystems and the species they support. This article is part of the theme issue 'Integrative research perspectives on marine conservation'.

In November 2001, we observed a herd of killer whales (Orcinus orca) preying upon a leatherback turtle (Dermochelys coriacea) off the coast of California. Here we provide details of the event and speculate that oceanic killer whales may have less specialized diets than nearshore populations. We also suggest that killer whale predation should be considered a factor in the recovery of this critically endangered sea turtle. [ABSTRACT FROM AUTHOR]