Search

The Northern California Current is a highly productive marine upwelling ecosystem that is economically and ecologically important. It is home to both commercially harvested species and those that are federally listed under the U.S. Endangered Species Act. Recently, there has been a global shift from single-species fisheries management to ecosystem-based fisheries management, which acknowledges that more complex dynamics can reverberate through a food web. Here, we have integrated new research into an end-to-end ecosystem model (i.e., physics to fisheries) using data from long-term ocean surveys, phytoplankton satellite imagery paired with a vertically generalized production model, a recently assembled diet database, fishery catch information, species distribution models, and existing literature. This spatially-explicit model includes 90 living and detrital functional groups ranging from phytoplankton, krill, and forage fish to salmon, seabirds, and marine mammals, and nine fisheries that occur off the coast of Washington, Oregon, and Northern California. This model was updated from previous regional models to account for more recent changes in the Northern California Current (e.g., increases in market squid and some gelatinous zooplankton such as pyrosomes and salps), to expand the previous domain to increase the spatial resolution, to include data from previously unincorporated surveys, and to add improved characterization of endangered species, such as Chinook salmon (Oncorhynchus tshawytscha) and southern resident killer whales (Orcinus orca). Our model is mass-balanced, ecologically plausible, without extinctions, and stable over 150-year simulations. Ammonium and nitrate availability, total primary production rates, and model-derived phytoplankton time series are within realistic ranges. As we move towards holistic ecosystem-based fisheries management, we must continue to openly and collaboratively integrate our disparate datasets and collective knowledge to solve the intricate problems we face. As a tool for future research, we provide the data and code to use our ecosystem model. [ABSTRACT FROM AUTHOR]

Three killer whale ecotypes are found in the Northeastern Pacific: residents, transients, and offshores. These ecotypes can be discriminated in passive acoustic data based on distinct pulsed call repertoires. Killer whale acoustic encounters for which ecotypes were assigned based on pulsed call matching were used to characterize the ecotype-specific echolocation clicks. Recordings were made using seafloor-mounted sensors at shallow (∼120 m) and deep (∼1400 m) monitoring locations off the coast of Washington state. All ecotypes' echolocation clicks were characterized by energy peaks between 12 and 19 kHz, however, resident clicks featured sub peaks at 13.7 and 18.8 kHz, while offshore clicks had a single peak at 14.3 kHz. Transient clicks were rare and were characterized by lower peak frequencies (12.8 kHz). Modal inter-click intervals (ICIs) were consistent but indistinguishable for resident and offshore killer whale encounters at the shallow site (0.21–0.22 s). Offshore ICIs were longer and more variable at the deep site, and no modal ICI was apparent for the transient ecotype. Resident and offshore killer whale ecotype may be identified and distinguished in large passive acoustic datasets based on properties of their echolocation clicks, however, transient echolocation may be unsuitable in isolation as a cue for monitoring applications. [ABSTRACT FROM AUTHOR]

The endangered Southern Resident killer whales (Orcinus orca) of the northeast Pacific region use two main types of vocal signals to communicate: discrete calls and whistles. Despite being one of the most-studied cetacean populations in the world, whistles have not been as heavily analyzed due to their relatively low occurrence compared to discrete calls. The aim of the current study is to further investigate the whistle repertoire and characteristics of the Southern Resident killer whale population. Acoustic data were collected between 2006-2007 and 2015-2017 in the waters around San Juan Island, Washington State, USA from boats and from shore. A total of 228 whistles were extracted and analyzed with 53.5% of them found to be stereotyped. Three of the four stereotyped whistles identified by a previous study using recordings from 1979-1982 were still occurring, demonstrating that whistles are stable vocalizations for a period of more than 35 years. The presence of three new stereotyped whistles was also documented. These results demonstrate that whistles share the longevity and vocal tradition of discrete calls, and warrant further study as a key element of Southern Resident killer whale communication and cultural transmission. [ABSTRACT FROM AUTHOR]

Chinook salmon (Oncorhynchus tshawytscha) along the west coast of North America have experienced significant declines in abundance and body size over recent decades due to several anthropogenic stressors. Understanding the reasons underlying the relatively high levels of persistent organic pollutants (POPs) in Chinook stocks is an important need, as it informs recovery planning for this foundation species, as well for the Chinook-dependent Resident killer whales (Orcinus orca , RKW) of British Columbia (Canada) and Washington State (USA). We evaluated the influence of stock-related differences in feeding ecology, using stable isotopes, and marine rearing ground on the concentrations and patterns of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in Chinook salmon. A principal components analysis (PCA) revealed a clear divergence of PCB and PBDE congener patterns between Chinook with a nearshore rearing distribution ('shelf resident') versus a more offshore distribution. Shelf resident Chinook had 12-fold higher PCB concentrations and 46-fold higher PBDE concentrations relative to offshore stocks. Shelf resident Chinook had PCB and PBDE profiles that were heavier and dominated by more bioaccumulative congeners, respectively. The higher δ13C and δ15N in shelf resident Chinook compared to the offshore rearing stocks, and their different marine distributions explain the large divergence in contaminant levels and profiles, with shelf resident stocks being heavily influenced by land-based sources of industrial contamination. Results provide compelling new insight into the drivers of contaminant accumulation in Chinook salmon, raise important questions about the consequences for their health, and explain a major pathway to the heavily POP-contaminated Resident killer whales that consume them. • Diet and marine migration underlie divergent contaminant profiles in Chinook salmon. • Shelf resident Chinook had higher δ13C and δ15N than offshore stocks. • Shelf resident Chinook had higher contaminant levels relative to offshore stocks. • Shelf resident Chinook contaminant profiles reflect proximity to land-based pollution. • Eliminating PCB and PBDE sources would benefit salmon and killer whales. [ABSTRACT FROM AUTHOR]

Admiralty Inlet, Puget Sound, Washington, has been selected as a potential tidal energy site. It is located near shipping lanes, is possibly a highly variable acoustic environment, and is frequented by the endangered Southern Resident killer whale (SRKW). Resolving environmental impacts is the first step to receiving approval to deploy tidal turbines. Several monitoring technologies are being considered to determine the presence of SRKW near the turbines. Broadband noise level measurements are critical for determining design and operational specifications of these technologies. Acoustic environment data at the proposed site were acquired at different depths using a cabled vertical line array from two cruises during flood and ebb tidal periods in May and June 2011. The ambient noise level decreases approximately 5 dB re 1 μPa per octave for frequency ranges of 1-70 kHz and increases approximately 5 dB re 1 μPa per octave for the frequency from 70 to 100 kHz. The difference between noise pressure levels in different months varies from 10 to 30 dB re 1 μPa for the frequency range below 70 kHz. Commercial shipping and ferry vessel traffic were found to be the most significant contributors to sound pressure levels for the frequency range of 1-50 kHz, and the variation could be as high as 30 dB re 1 μPa. These noise level measurements provide the basic information for designing and evaluating both active and passive monitoring systems proposed for deployment and operation of a tidal power generation alert system. [ABSTRACT FROM AUTHOR]

A major criterion for permitting the deployment of tidal turbines in Washington State's Puget Sound is management of risk of injury to killer whales from collision with moving turbine blades. An active monitoring system is being proposed to detect and track killer whales within proximity of turbines and alert turbine operators of their presence and location to permit temporary turbine shutdown when the risk of collision is high. Knowledge of the target strength (TS) of killer whales is critical to the design and application of active acoustic monitoring systems. In 1996, a study of the IS directivity of a 2.2-m-long bottlenose dolphin at an insonifying frequency of 67 kHz was performed. Noting that killer whales, which are dolphins, are morphologically similar to bottlenose dolphins and then assuming allometry, we estimated the relative broadside and tail aspect TS of a 7.5-m-long adult killer whale at an insonifying frequency of 67 kHz to be -8 and -28 dB, respectively. We used a three-layer model for plane wave reflection of sound at 200 kHz from the lung of killer whales to estimate their IS. We assessed the accuracy of our killer whale IS estimates by comparing them with IS estimates of free swimming killer whales obtained using a split-beam active acoustic system operating at 200 kHz. The killer whale TS estimates based on the preliminary model were in good agreement with those obtained for free swimming killer whales. [ABSTRACT FROM AUTHOR]

The article discusses the initiatives of the government to address the effects of climate change on marine mammals and killer whales in Puget Sound, Washington. Governor Chris Gregorie has allocated $42 million for the restoration and protection of whales in 2005, while the State Legislature has passed the H.R. 2815 which requires reduction of emission levels. Furthermore, another legislation Initiative-937 was approved which allows large companies to use 15 percent of their electricity from clean energy sources.

Focuses on the threats to the population of killer whales at the Salish Sea in Puget Sound, Washington. Health risks posed by polychlorinated biphenyls; Decline in salmon population in the Pacific Northwest; Threat posed by whale-watchers; Action taken by environmental groups to address the problem.

Underwater noise of whale-watching boats was recorded in the popular killer whale-watching region of southern British Columbia and northwestern Washington State. A software sound propagation and impact assessment model was applied to estimate zones around whale-watching boats where boat noise was audible to killer whales, where it interfered with their communication, where it caused behavioral avoidance, and where it possibly caused hearing loss. Boat source levels ranged from 145 to 169 dB re 1 µPa @ 1 m, increasing with speed. The noise of fast boats was modeled to be audible to killer whales over 16 km, to mask killer whale calls over 14 km, to elicit a behavioral response over 200 m, and to cause a temporary threshold shift (TTS) in hearing of 5 dB after 30-50 min within 450 m. For boats cruising at slow speeds, the predicted ranges were 1 km for audibility and masking, 50 m for behavioral responses, and 20 m for TTS. Superposed noise levels of a number of boats circulating around or following the whales were close to the critical level assumed to cause a permanent hearing loss over prolonged exposure. These data should be useful in developing whale-watching regulations. This study also gave lower estimates of killer whale call source levels of 105-124 dB re 1 µPa. [ABSTRACT FROM AUTHOR]

The article offers information on the research conducted by Peter Ross and his colleagues on the source of the pollutants in the resident orcas inhabiting waters off British Columbia and Washington State. The research shows that salmon acquire most of their persistent organic pollutant (POP) load in the Pacific Ocean. Moreover, 40% of the atmospheric polybrominated diphenyl ethers PBDEs originates in Asia.

The article features the Southern Resident killer whales, listed as one of the endangered species in Washington and a part of the yearly Puget Sound event in the state. The killer whales were reported by the National Marine Fisheries Service to be the recent subject to extinction. The federal government in the U.S. developed a wildlife conservation legislation, the Endangered Species Act, to keep the whales' population in check. Possible causes of the decline include vessel traffic, toxic chemical contamination in the water, and lesser food supply.

Reports on the success of the rescue and reintroduction of Springer, an orphan killer whale, by scientists in Puget Sound, Washington in October 2004.

Background noise can interfere with the detection and discrimination of crucial signals among members of a species. Here we investigate the vocal behaviour in the presence and absence of whale-watcher boat traffic of three social groups (pods) of killer whales (Orcinus orca) living in the nearshore waters of Washington state. We find longer call durations in the presence of boats for all three pods, but only in recent recordings made following a period of increasing boat traffic. This result indicates that these whales adjust their behaviour to compensate for anthropogenic noise once it reaches a threshold level. [ABSTRACT FROM AUTHOR]