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Introduction: Coastal marine ecosystems, are particularly susceptible to climate change. One such threat is atmospheric heatwaves, which are predicted to increase in frequency, duration, and intensity. Many intertidal organisms already live at the edge of their thermal tolerance limits and heatwaves can outstretch an organism's ability to compensate in the short term. In June 2021 the Pacific Northwest region of North America, including the Salish Sea, experienced a significant atmospheric heatwave during some of the lowest tides of the year. This was followed by numerous reports of dead and dying intertidal marine organisms region-wide. A semi-quantitative rapid assessment found a range of both species- and location-specific effects but generally recorded widespread negative impacts to intertidal shellfish species across the Salish Sea. Methods: Following these results, we opportunistically analyzed data collected by intertidal bivalve resource managers from the region. These datasets allowed us to examine regional density and size data for clam and oyster populations before and after the heatwave to increase our quantitative understanding of heatwave effects. Results: We found a range of responses including positive and negative effects of the heatwave on clam and oyster density. While we generally found small changes in bivalve size, some site-species combinations displayed large shifts in size frequency. Many of our analyses did not indicate even moderate statistical support, even with large changes in the mean, driven in part by high variability in the data. Time intervals between surveys, ranging from 2 to over 25 months, had little effect on observed variability indicating that any heatwave-induced effects may be masked by variability inherent to the population ecology and/or survey methodology. Discussion: This analysis has highlighted the need for intertidal resource managers, and the greater research community, to consider alternative survey approaches designed to constrain variability in order to detect the effects of acute or extreme events. With the effects of climate change predicted to become more intense, targeted survey approaches may be needed to detect the effects and implications of such events and to continue effective management of intertidal bivalves in the Salish Sea and worldwide. [ABSTRACT FROM AUTHOR]

This article discusses the observation of the critically endangered soupfin shark in the Changing Salish Sea. The study confirms the presence of soupfin sharks in Hammersley Inlet through fishing efforts and sampling. The findings suggest that the presence of soupfin sharks may have implications for trophic dynamics and fisheries management in the region. The article also provides a list of references for further research on marine ecosystems in the Salish Sea and surrounding areas. [Extracted from the article]

Little is known about the in-water behavior and site fidelity of harbor seals (Phoca vitulina richardii), as most photo-identification (photo-ID) studies are typically conducted while they are hauled-out on land. We investigated in-water site fidelity rates and seasonal presence in Burrows Pass, Washington, using photographs collected during a long-term photo-ID and behavioral study from January 2015 through November 2019. There was a minimum of 161 individuals and a maximum of 286 individual harbor seals using Burrows Pass. Harbor seals were present in all seasons, with the lowest sighting rates during summer. Individuals were more likely to be sighted/re-sighted in fall and spring. There was large variations in the level and seasonality of site fidelity among individuals. The majority of seals (69.62%) were seen only once, but 22.69% showed low to moderate site fidelity (2–5 sightings) and 7.69% showed strong site fidelity (≥6 sightings) over seasons and across years. These seasonal variations were likely due to foraging, life history, and individual behavioral variabilities. Studies like this provide necessary information about harbor seal in-water site fidelity and behavior, which are less well known but vitally important in harbor seal management and conservation.

The Salish Sea supports several baleen whale species, including humpback (Megaptera novaeangliae), gray (Eschrichtius robustus) and minke whales (Balaenoptera acutorostrata). With the exception of minke whales, these species were decimated by commercial whaling in the 1900s. Because recovery of these populations is monitored on broad spatial scales determined by stocks or populations, their use of the Salish Sea ecosystem is not well documented or understood. We collated 17,436 opportunistic sighting reports to assess patterns in mysticete presence and distribution in the Salish Sea (1976-2019). We used the proportion of sightings for each species and spatial models targeting comparisons between species to limit the influence of spatio-temporal variation in reporting efforts. Humpback whale sightings have increased dramatically since the late 2000s, mirroring population-wide increases and suggesting a renewed use of historically important feeding areas. Gray whale sightings increased most notably at two distinct times (1989, 2017), both of which align with periods of high mortality experienced by the delisted Eastern North Pacific stock of gray whales and may reflect individuals straying from their migration routes. Sightings of minke whales remained relatively stable over this study period and were likely driven by a group of 30-40 individuals that forage off shallow banks and bathymetrically complex habitats around the San Juan Archipelago. Though it can be difficult to separate the bias that accompanies public sightings databases, citizen science efforts are invaluable for monitoring the recovery of rebounding populations and can illuminate longitudinal patterns that would otherwise go unnoticed. [ABSTRACT FROM AUTHOR]

The distinguishing features of a previously unknown amphibious Isoetes discovered in coastal British Columbia, Canada are described. Although occurring in an ephemeral, vernal, seaside rock pool habitat thought to be indicative of I. nuttallii, field observations and morphological investigations determined these plants to be a distinctive taxon possessing small and boldly ornamented megaspores, relatively large microspores, and a regionally unique short velum coverage of the sporangia. It is reminiscent, particularly in spore ornamentation, of the aquatic, mid-season I. maritima and is known from one site (possibly two) where no living plants are presently evident. A unique combination of uncommon morphological features, restricted geographic range, rare habitat, and early growth season distinguishes these plants as distinct from all known Isoetes taxa. Isoetes salishensis, sp. nov. is proposed as an addition to the growing list of flora and fauna endemic to or centered on the Salish Sea area of southwestern British Columbia and northwestern Washington State. [ABSTRACT FROM AUTHOR]

Little is known about the in-water behavior and site fidelity of harbor seals (Phoca vitulina richardii), as most photo-identification (photo-ID) studies are typically conducted while they are hauled-out on land. We investigated in-water site fidelity rates and seasonal presence in Burrows Pass, Washington, using photographs collected during a long-term photo-ID and behavioral study from January 2015 through November 2019. There was a minimum of 161 individuals and a maximum of 286 individual harbor seals using Burrows Pass. Harbor seals were present in all seasons, with the lowest sighting rates during summer. Individuals were more likely to be sighted/re-sighted in fall and spring. There was large variations in the level and seasonality of site fidelity among individuals. The majority of seals (69.62%) were seen only once, but 22.69% showed low to moderate site fidelity (2–5 sightings) and 7.69% showed strong site fidelity (≥6 sightings) over seasons and across years. These seasonal variations were likely due to foraging, life history, and individual behavioral variabilities. Studies like this provide necessary information about harbor seal in-water site fidelity and behavior, which are less well known but vitally important in harbor seal management and conservation. [ABSTRACT FROM AUTHOR]

Harbor porpoises (Phocoena phocoena) are the only cetaceans routinely sighted in Hood Canal, a narrow fjord that comprises the western edge of Puget Sound, Washington, USA. Harbor porpoises are sensitive to anthropogenic sounds, including noise from recreational and commercial vessel traffic, and the United States Navy, which conducts military training and testing within Hood Canal that can include underwater sound sources. This study was funded as part of the Navy monitoring program to assess potential impacts of naval activities on cetaceans. We conducted vessel-based line-transect surveys for harbor porpoises in Hood Canal in 2022-2023 to derive seasonal estimates of abundance and density. We carried out surveys over 37 days and surveyed the entire canal twice per season totaling 2,176 km of on-effort track line. We recorded 809 oneffort harbor porpoise groups and 1,385 individuals. Seasonal abundance estimates were lowest in winter (308 animals, 95% CI = 189-503) and gradually increased through spring and summer to a peak of 1,336 animals (95% CI = 826-2,160) in fall. Overall porpoise density was highest in central Hood Canal, an area that includes a designated United States Navy training range, though porpoise sightings were notably absent in a 21-km² area adjacent to the naval submarine base within this otherwise high-density region. Though we collected only a single year of data, these results suggest that harbor porpoise abundance in Hood Canal increased significantly since it was last estimated (2013-2015). The notable seasonal fluctuation of harbor porpoise abundance suggests Hood Canal may host a larger percentage of the overall Washington Inland Waters stock during the fall season, raising important management considerations. [ABSTRACT FROM AUTHOR]

The pelagic food webs of British Columbia's (BC) coastal oceans have never had a comprehensive review of their trophic structure. In this study, we analyzed carbon (δ13C) and nitrogen (δ15N) stable isotope ratios of pelagic food web components collected from four regions in southern BC: Juan de Fuca Strait, the Strait of Georgia, Queen Charlotte Strait, and Queen Charlotte Sound during an August 2019 survey. In addition, conductivity, temperature, and depth (CTD), chlorophyll, and nutrient data were collected to assess the oceanographic basis for regionalization. Between regions, we observed differences in the isotopic baseline driven by regional oceanography. Likewise, we also observed oceanography-driven differences in regional food chain length, carbon range, and isotopic overlap. Species-specific trophic level and isotopic niche were determined. For common pelagic species, we described how trophic level varied regionally, was not always in line with previously published dietary data, and instead largely tracked regional changes in food chain length. We conclude that variable food web properties and trophic ecology can manifest across the small spatial scales of the BC coast's discrete regions. [ABSTRACT FROM AUTHOR]

Endangered Southern Resident killer whales (Orcinus orca) are fish‐eaters that preferentially prey on adult Chinook salmon (Oncorhynchus tshawytscha). Despite being salmon specialists, individuals from all three killer whale pods (J, K, L) have been observed harassing and killing porpoises (family Phocoenidae) without consuming them. Retrospectively, we identified and analyzed 78 episodes of Southern Resident killer whales harassing porpoises between 1962 and 2020, of which 28 resulted in the porpoise's death ("phocoenacide"). Fifty‐six episodes involved harbor porpoise (Phocoena phocoena), 13 involved Dall's porpoise (Phocoenoides dalli), and the porpoise species was unreported for nine episodes. Southern Resident killer whales often targeted young porpoises that were similar in size to adult Chinook salmon. Both sexes participated in porpoise harassment. Juveniles engaged in the behavior the most; however, their rates of engagement were not found to differ significantly from most other age classes. The behavior was passed through generations and social groupings, as it was first observed in L pod and spread to the other two pods. Killer whales are highly complex animals known to exhibit social learning and cultural transmission of learned behaviors, but the reason(s) for this behavior is unknown. Hypotheses include the social and developmental benefits of play, hunting practice, or displaced epimeletic behavior. [ABSTRACT FROM AUTHOR]

The Salish Sea, a dynamic system of straits, fjords, and channels in southwestern British Columbia, is home to ecologically and culturally important bull kelp (Nereocystis luetkeana) forests. Yet the long-term fluctuations in the area and the persistence of this pivotal coastal marine habitat are unknown. Using very high-resolution satellite imagery to map kelp forests over two decades, we present the spatial changes in kelp forest area within the Salish Sea, before (2002 to 2013) and after (2014 to 2022) the ‘Blob,’ an anomalously warm period in the Northeast Pacific. This analysis was spatially constrained by local environmental conditions. Based on nearshore sea surface temperatures (SSTs) from four decades (1984–2022), we found two periods of distinct increases in SST, one starting in 2000 and another in 2014. Further, the highest SST anomalies occurred on warmer coastlines in the enclosed inlets and the Strait of Georgia, while smaller anomalies were found on colder coastlines near the Strait of Juan de Fuca and the Discovery Passage. The total area of bull kelp forests from 2014 to 2022 has decreased compared to 2002 to 2013, particularly in the northern sector of the Salish Sea. Using the satellite-derived kelp data, we also present an analysis of kelp persistence compared with historical distribution of kelp forests depicted on British Admiralty Nautical Charts from 1858 to 1956. This analysis shows that warm, sheltered areas experienced a considerable decrease in persistence of kelp beds when compared to satellite-derived distribution of modern kelp, confirming a century-scale loss. In particular, the presence of kelp forests in the Strait of Georgia and on the warmest coasts has decreased considerably over the century, likely due to warming temperatures. While the coldest coasts to the south have maintained their centennial persistence, the northern Salish Sea requires further research to understand its current dynamics. This research contributes to a wider understanding of temporal and spatial factors for kelp from the regional perspective of the Salish Sea.

IntroductionCoastal marine ecosystems, are particularly susceptible to climate change. One such threat is atmospheric heatwaves, which are predicted to increase in frequency, duration, and intensity. Many intertidal organisms already live at the edge of their thermal tolerance limits and heatwaves can outstretch an organism’s ability to compensate in the short term. In June 2021 the Pacific Northwest region of North America, including the Salish Sea, experienced a significant atmospheric heatwave during some of the lowest tides of the year. This was followed by numerous reports of dead and dying intertidal marine organisms region-wide. A semi-quantitative rapid assessment found a range of both species- and location-specific effects but generally recorded widespread negative impacts to intertidal shellfish species across the Salish Sea. MethodsFollowing these results, we opportunistically analyzed data collected by intertidal bivalve resource managers from the region. These datasets allowed us to examine regional density and size data for clam and oyster populations before and after the heatwave to increase our quantitative understanding of heatwave effects. ResultsWe found a range of responses including positive and negative effects of the heatwave on clam and oyster density. While we generally found small changes in bivalve size, some site-species combinations displayed large shifts in size frequency. Many of our analyses did not indicate even moderate statistical support, even with large changes in the mean, driven in part by high variability in the data. Time intervals between surveys, ranging from 2 to over 25 months, had little effect on observed variability indicating that any heatwave-induced effects may be masked by variability inherent to the population ecology and/or survey methodology. DiscussionThis analysis has highlighted the need for intertidal resource managers, and the greater research community, to consider alternative survey approaches designed to constrain variability in order to detect the effects of acute or extreme events. With the effects of climate change predicted to become more intense, targeted survey approaches may be needed to detect the effects and implications of such events and to continue effective management of intertidal bivalves in the Salish Sea and worldwide.

Anadromous salmonid species vary in their use of open ocean, coastal, and inland marine waters. To better understand this diversity in behavior and habitat use, 120 coastal cutthroat trout, Oncorhynchus clarkii clarkii, were caught in southern Puget Sound, Washington, USA, tagged with acoustic transmitters, and 95 were detected by a network of receiver stations. Despite sufficient time to reach other parts of the Salish Sea where many receivers operated, none was detected beyond southern Puget Sound, indicating localized movements. Within southern Puget Sound, fish were detected at 34 of 127 receivers in marine sites throughout the year but especially in spring and fall. Most detection events (between first and last detections at a given receiver) were brief (60.5% were ≤ 2 h and 76.8% ≤ 6 h), indicating movement along the shoreline. However, 823 events (12.8%) exceeded 12 h and 222 (3.4%) exceeded 24 h at a receiver, indicating longer occupancy at certain sites and by certain individuals. The detections also indicated that cutthroat trout were active throughout the 24-h period, but they moved more often at night and less often in other periods than would occur by chance, and they moved more often on ebbing and flooding tides and less often at slack periods. Fish with pressure-sensitive transmitters were almost always (97.3% of records) within 2.5 m of the surface and 76.8% between 1 – 2 m, despite deeper and shallower waters nearby where they could have been detected. The data provide new insights into the behavior of this species, whose marine ecology has not been extensively studied, and differs markedly from the region's other native salmonids. [ABSTRACT FROM AUTHOR]

Zooplankton and ichthyoplankton community assessments depend on species diagnostics, yet morphological identifications are time-consuming, require taxonomic expertise, and are hampered by a lack of diagnostic characters, particularly for larval stages. Metabarcoding can identify multiple species in communities from short DNA sequences in comparison to reference databases. To evaluate species resolution across phylogenetic groups and food webs of zooplankton and ichthyoplankton, we compare five metabarcode mitochondrial (mt)DNA markers from gene regions of (a) cytochrome c oxidase subunit I, (b) cytochrome b, (c) 16S ribosomal RNA, and (d) 12S ribosomal RNA for DNA extracted from net tows in the Northeastern Pacific Ocean's Salish Sea across seven sites and two seasons. Species resolved by metabarcoding are compared to invertebrate morphological identifications and biomass estimates. Results indicate that species resolution for different zooplankton and ichthyoplankton taxa can markedly vary among gene regions and markers in comparison to morphological identifications. Thus, researchers seeking "universal" metabarcoding should take caution that several markers and gene regions likely will be needed; all will miss some taxa and yield incomplete overlap. Species resolution requires careful attention to taxon marker selection and coverage in reference sequence repositories. In summary, combined multi-marker metabarcoding and morphological approaches improve broadscale zooplankton diagnostics. [ABSTRACT FROM AUTHOR]

The impacts of local-scale temperatures and winds on bull kelp (Nereocystis luetkeana) vary along a coastal gradient, while also being influenced by corresponding global-scale oceanic conditions. Around Vancouver Island and the Gulf Islands, BC, Canada, bull kelp floating canopies were mapped using high-resolution imagery from 2005 to 2022, whereas the largest kelp bed of the area wasmapped withmedium-resolution imagery spanning from1972 to 2022. In order to understand spatial patterns of kelp resilience, the abiotic characteristics were used to organize the coastline into four clusters, ranging fromthe coldest and most exposed coast to a more sheltered and warmer location. Additionally, localscale sea surface temperatures, winds, andmarine heatwaves were categorized by global-scale temporal conditions defined by the positive/negative oceanic oscillations of the Oceanic Niño Index (ONI) and Pacific Decadal Oscillation (PDO). Comparing spatial and temporal categories, we observed that years with positive ONI and PDO, in particular the 2014-2019 period, concentrated most of themarine heatwaves and the spring temperature peaks. However, there are some indications of an underlying long-termtrend. During the period 2020-2022, when ONI and PDO were negative, summer temperatures kept increasing and wind displayed a higher frequency of extreme events. Mapped kelp showed different trends to these stressors: the coldest and most exposed area showed a constant presence of kelp during the entire period, even dating back to 1972. Warmer and semi-sheltered coasts increased in kelp percentage cover after the positive ONI +PDO period of 2014-2019, and the coasts facing the Strait of Georgia displayed a lower kelp percentage cover than the other clusters. In summary, bull kelp was resilient in the study area, but for different reasons: colder and more exposed coasts had the most favorable conditions for kelp, but warmer and more sheltered coastal kelp beds may have benefited from wind-wave forcing. [ABSTRACT FROM AUTHOR]

Extreme water-level recurrence estimates for a complex estuary using a high-resolution 2D model and a new method for estimating remotely generated sea level anomalies (SLAs) at the model boundary have been developed. The hydrodynamic model accurately resolves the dominant physical processes contributing to extreme water levels across the Washington State waters of the Salish Sea, including the relative contribution of remote SLA and other non-tidal residual processes that drive extreme water levels above the predicted tide. The model's predictions have errors of less than 15 cm (<5% of 3–4 m tidal range) at eight tide gauge locations across the model domain. The influence of remote SLAs at the seaward boundary of the model was implemented using a multivariate regression of readily available and locally relevant wind, sea surface temperature, and pressure anomaly data, combined with El Niño Index data (R2 = 0.76). The hydrodynamic model simulations using the remote SLA predictor compared well with simulations using the widely used data-assimilative global ocean model HYCOM SLA data (root mean square difference of 5.5 cm). Extreme water-level recurrence estimates with and without remote SLA show that remote forcing accounts for 50–60% of the total water level anomaly observed along Salish Sea shorelines. The resulting model simulations across decadal timescales provide estimates of extreme water level recurrence across the Salish Sea, capturing climate variability important to long-term coastal hazard planning. This approach has widespread applications for other complex estuarine systems. [ABSTRACT FROM AUTHOR]

The Salish Sea supports several baleen whale species, including humpback (Megaptera novaeangliae), gray (Eschrichtius robustus) and minke whales (Balaenoptera acutorostrata). With the exception of minke whales, these species were decimated by commercial whaling in the 1900s. Because recovery of these populations is monitored on broad spatial scales determined by stocks or populations, their use of the Salish Sea ecosystem is not well documented or understood. We collated 17,436 opportunistic sighting reports to assess patterns in mysticete presence and distribution in the Salish Sea (1976–2019). We used the proportion of sightings for each species and spatial models targeting comparisons between species to limit the influence of spatio-temporal variation in reporting efforts. Humpback whale sightings have increased dramatically since the late 2000s, mirroring population-wide increases and suggesting a renewed use of historically important feeding areas. Gray whale sightings increased most notably at two distinct times (1989, 2017), both of which align with periods of high mortality experienced by the delisted Eastern North Pacific stock of gray whales and may reflect individuals straying from their migration routes. Sightings of minke whales remained relatively stable over this study period and were likely driven by a group of 30–40 individuals that forage off shallow banks and bathymetrically complex habitats around the San Juan Archipelago. Though it can be difficult to separate the bias that accompanies public sightings databases, citizen science efforts are invaluable for monitoring the recovery of rebounding populations and can illuminate longitudinal patterns that would otherwise go unnoticed.

The impacts of local-scale temperatures and winds on bull kelp (Nereocystis luetkeana) vary along a coastal gradient, while also being influenced by corresponding global-scale oceanic conditions. Around Vancouver Island and the Gulf Islands, BC, Canada, bull kelp floating canopies were mapped using high-resolution imagery from 2005 to 2022, whereas the largest kelp bed of the area was mapped with medium-resolution imagery spanning from 1972 to 2022. In order to understand spatial patterns of kelp resilience, the abiotic characteristics were used to organize the coastline into four clusters, ranging from the coldest and most exposed coast to a more sheltered and warmer location. Additionally, local-scale sea surface temperatures, winds, and marine heatwaves were categorized by global-scale temporal conditions defined by the positive/negative oceanic oscillations of the Oceanic Niño Index (ONI) and Pacific Decadal Oscillation (PDO). Comparing spatial and temporal categories, we observed that years with positive ONI and PDO, in particular the 2014–2019 period, concentrated most of the marine heatwaves and the spring temperature peaks. However, there are some indications of an underlying long-term trend. During the period 2020–2022, when ONI and PDO were negative, summer temperatures kept increasing and wind displayed a higher frequency of extreme events. Mapped kelp showed different trends to these stressors: the coldest and most exposed area showed a constant presence of kelp during the entire period, even dating back to 1972. Warmer and semi-sheltered coasts increased in kelp percentage cover after the positive ONI+PDO period of 2014–2019, and the coasts facing the Strait of Georgia displayed a lower kelp percentage cover than the other clusters. In summary, bull kelp was resilient in the study area, but for different reasons: colder and more exposed coasts had the most favorable conditions for kelp, but warmer and more sheltered coastal kelp beds may have benefited from wind-wave forcing.

The San Juan archipelago lies along the axis of tidal movement between Straits of Juan de Fuca and Strait of Georgia in the Salish Sea. The amplitude of the tidal exchange produces significant tidal currents between the islands, as well as in Rosario Strait to the east and Haro Strait to the west. These currents are of interest as a future source of electrical power generation, given the archipelago's dependence on electricity supply by a subsea cable from the United States mainland. Here, we evaluate the tidal current energy potential in this region through a re-analysis of measurements collected by the National Ocean Service (NOS) and a high-resolution numerical model. Given the considerable variations in water depth and vertical velocity profiles across candidate tidal energy sites, we consider the trade-offs between tidal turbines deployed from a floating platform and those anchored to the seabed. Measurement re-analysis indicates several locations that could support tidal current power generation by MW-scale turbines with an acceptable balance between turbine size, rated power, and capacity factor. Even for relatively large (30 m) turbine diameters, surface-deployed turbines would be expected to produce up to 30 % more electricity than the same turbine deployed near the seabed due to vertical shear, with this difference increasing for smaller diameter turbines. As anticipated for sparse measurements, the regional simulation identifies several locations with power generation potential more than twice as high as locations in the measurement re-analysis. These sites were either not surveyed or excluded due to data quality issues. A benchmark comparison at the measurement locations with the highest power generation potential shows relatively good model fidelity, though time-average power density disagreements of ± 50 % persist throughout the water column. In addition to the case study, we also treat three general considerations for measurement data: (1) the accuracy of energy generation estimates from hub height speed relative to rotor-averaged power density, (2) the feasibility of extrapolating profiles towards the surface and seabed, and (3) trends in energy generation with rotor size and position in the water column. Overall, these results demonstrate that models and measurements can be used in a complementary manner for tidal energy site assessment and that tidal currents could be an important source of electricity generation in the San Juan archipelago. • Locations in the San Juan archipelago could support tidal current power generation. • Turbines near the surface produce 30 % more power than those near the seabed. • Simulations indicate sites with more than 2x generation of those with measurements. • Hub-height speed is a good approximation for rotor-averaged kinetic power density. • Tangent or power law fits can be used to extrapolate measurements, when needed. [ABSTRACT FROM AUTHOR]

Haul-out sites of harbor seals, Phoca vitulina Linnaeus, 1758, include areas with high levels of anthropogenic noise. In some cases, seals haul out at night when there are lower in-air noise levels. However, it is unclear whether there are additional responses to noise pollution. To determine potential impacts of anthropogenic noise on haul-out behavior, we compared numbers of hauled-out harbor seals relative to in-air noise levels at two sites in Washington state, USA—one close to human activities (Bellingham waterfront) and one more distant (Semiahmoo marina)—between July 2020 and August 2021. We used generalized linear mixed models to identify predictors of seal numbers. The marina had lower mean noise levels than the waterfront (39.7 ± SD 6.1 dB, n = 29 observations versus 51.2 ± SD 5.2 dB, n = 126 observations). The plotted model prediction showed a significantly negative association between noise and seals at the marina, and no association was found at the waterfront. Results indicate that in-air noise levels may influence seal numbers at sites where human activities are low. They also suggest that, besides hauling out at night, seals may become tolerant to in-air noise levels at sites where human activities are high. [ABSTRACT FROM AUTHOR]

Harbor porpoises are typically seen in small groups of 1–3 individuals, with aggregations of 20+ individuals treated as rare events. Since the 1990s, the harbor porpoise population in the Salish Sea has seen a significant recovery, and an increased number of observed aggregations that exceed the more usual small group sizes has been observed in recent years. By combining the observational data of United States and Canadian research organizations, community scientists, and whale watch captains or naturalists, we demonstrate that harbor porpoise aggregations appear to be more common than previously known, with 160 aggregations documented in 2022 alone. Behavioral data also indicate that foraging behaviors are common and social behaviors, like mating, are seen more often during these encounters compared to small groups. Other behaviors that are considered to be rare or unknown were also observed during these encounters, including cooperative foraging and vessel approach. These aggregations are likely important foraging and social gatherings for harbor porpoises. This holistic approach integrating data from two countries and multiple sources provides a population level assessment that more effectively reflects the behavior of harbor porpoises in this region, which do not recognize the socio-political boundaries imposed upon the natural world. [ABSTRACT FROM AUTHOR]

The fish-eating Southern Resident killer whales (Orcinus orca) of the northeastern Pacific are listed as Endangered in both the USA and Canada. The inland waters of Washington State and British Columbia, a region known as the Salish Sea, are designated as Southern Resident critical habitat by both countries. The whales have historically had regular monthly presence in the Salish Sea, with peak abundance occurring from May through September. In recent years, at least partially in response to shifting prey abundance, habitat usage by the Southern Residents has changed. As conservation measures aim to provide the best possible protection for the whales in their hopeful recovery, it is key that policies are based both on historic trends and current data. To this aim, our study shares 2018-2022 daily occurrence data to build upon and compare to previously published whale presence numbers and to demonstrate more recent habitat shifts. Based on reports from an extensive network of community scientists as well as online streaming hydrophones, every Southern Resident occurrence was confirmed either visually or acoustically. Documented here are the first-ever total absence of the Southern Residents in the Salish Sea in the months of May, June, and August, as well as their continued overall declining presence in the spring and summer, while fall and winter presence remains relatively high. It is key that management efforts consider these shifting presence patterns when setting both seasonal and regional protection measures aimed at supporting population recovery. [ABSTRACT FROM AUTHOR]

To better understand the significance of sediments in driving bottom water hypoxia and eutrophication, benthic fluxes of dissolved oxygen (DO), dissolved inorganic carbon (DIC), pH, total alkalinity, and nutrients between the sediment and the overlying water were measured at 42 sites in the Salish Sea, in April and May 2018. Fluxes of DO were generally larger than DIC fluxes, likely due to the oxidation of reduced compounds stored in sediments. The average phosphorus flux was close to zero, indicating phosphorus storage in sediments. At all but two sites, denitrification was present, with a median rate of 1 mmol m−2 d−1. The spatial variation observed in benthic fluxes and denitrification rates was primarily driven by water column depth and bottom water DO. Denitrification rates were estimated to remove 11% of the dissolved inorganic nitrogen supplied to the bottom water in Hood Canal, whereas in the Main Basin only 1% was removed. This difference was due to the long bottom water residence time in Hood Canal. Essentially all particulate phosphorus that reached the seafloor during early spring was stored in the sediment. Sediment oxygen uptake accounted for approximately 19% of bottom water DO removal in Hood Canal and 18% in the South Sound, compared to estimates of 4.1 to 10% in the other two basins. These results illuminate the varying contributions that sediments make to bottom water chemistry and the environmental factors that drive this variation. [ABSTRACT FROM AUTHOR]

The fish-eating Southern Resident killer whales (Orcinus orca) of the northeastern Pacific are listed as Endangered in both the USA and Canada. The inland waters of Washington State and British Columbia, a region known as the Salish Sea, are designated as Southern Resident critical habitat by both countries. The whales have historically had regular monthly presence in the Salish Sea, with peak abundance occurring from May through September. In recent years, at least partially in response to shifting prey abundance, habitat usage by the Southern Residents has changed. As conservation measures aim to provide the best possible protection for the whales in their hopeful recovery, it is key that policies are based both on historic trends and current data. To this aim, our study shares 2018–2022 daily occurrence data to build upon and compare to previously published whale presence numbers and to demonstrate more recent habitat shifts. Based on reports from an extensive network of community scientists as well as online streaming hydrophones, every Southern Resident occurrence was confirmed either visually or acoustically. Documented here are the first-ever total absence of the Southern Residents in the Salish Sea in the months of May, June, and August, as well as their continued overall declining presence in the spring and summer, while fall and winter presence remains relatively high. It is key that management efforts consider these shifting presence patterns when setting both seasonal and regional protection measures aimed at supporting population recovery.

Graceful kelp crabs (Pugettia gracilis) are abundant consumers in shallow subtidal ecosystems of the Salish Sea. These dynamic habitats are currently experiencing multiple changes including invasion by non-native seaweeds and ocean warming. However, little is known about P. gracilis' foraging ecology, therefore we investigated their feeding preferences between native and invasive food sources, as well as feeding rates at elevated temperatures to better assess their role in changing coastal food webs. To quantify crab feeding preferences, we collected P. gracilis from San Juan Island, WA and conducted no-choice and choice experiments with two food sources: the native kelp, Nereocystis luetkeana, and the invasive seaweed, Sargassum muticum. In no-choice experiments, P. gracilis ate equal amounts of N. luetkeana and S. muticum. However, in choice experiments, P. gracilis preferred N. luetkeana over S. muticum. To test effects of temperature on these feeding rates, we exposed P. gracilis to ambient (11.5 ± 1.3 ℃) or elevated (19.5 ± 1.8 ℃) temperature treatments and measured consumption of the preferred food type, N. luetkeana. Crabs exposed to elevated temperatures ate significantly more than those in the ambient treatment. Our study demonstrates the diet flexibility of P. gracilis, suggesting they may be able to exploit increasing populations of invasive S. muticum in the Salish Sea. Warming ocean temperatures may also prompt P. gracilis to increase feeding, exacerbating harmful impacts on N. luetkeana, which is already vulnerable to warming and invasive competitors. [ABSTRACT FROM AUTHOR]

Understanding the response of predators to ecological change at multiple temporal scales can elucidate critical predator–prey dynamics that would otherwise go unrecognized. We performed compound‐specific nitrogen stable isotope analysis of amino acids on 153 harbor seal museum skull specimens to determine how trophic position of this marine predator has responded to ecosystem change over the past century. The relationships between harbor seal trophic position, ocean condition, and prey abundance, were analyzed using hierarchical modeling of a multi‐amino‐acid framework and applying 1, 2, and 3 years temporal lags. We identified delayed responses of harbor seal trophic position to both physical ocean conditions (upwelling, sea surface temperature, freshwater discharge) and prey availability (Pacific hake, Pacific herring, and Chinook salmon). However, the magnitude and direction of the trophic position response to ecological changes depended on the temporal delay. For example, harbor seal trophic position was negatively associated with summer upwelling but had a 1‐year delayed response to summer sea surface temperature, indicating that some predator responses to ecosystem change are not immediately observable. These results highlight the importance of considering dynamic responses of predators to their environment as multiple ecological factors are often changing simultaneously and can take years to propagate up the food web. [ABSTRACT FROM AUTHOR]

The Salish Sea experiences substantial vessel traffic and is vulnerable to impacts from vessel-source pollution. In response to anticipated increases in vessel traffic and risk of oil spills, the non-profit organization Friends of the San Juans advocated for the United States and Canada to adopt a transboundary Particularly Sensitive Sea Area (PSSA) through the Interna-tional Maritime Organization. However, neither State ultimately supported a PSSA proposal. This article examines the unsuccessful PSSA proposal for the Salish Sea within the broader context of the PSSA mechanism to under-stand the limitations of PSSAs and provide insight into why and how PSSA designations have changed over time. Here, the Salish Sea case presents an opportunity to examine the factors that States weigh when deciding whether to propose a PSSA, and how these factors relate to potential limita-tions of the PSSA mechanism. States with a history of transnational cooper-ation, such as the United States and Canada, may be more averse to using a PSSA mechanism when more familiar and trusted systems for bilateral co-operation exist. In this way, States may rely on existing institutions, prece-dents, and agreements for transboundary collaboration between one an-other and with indigenous communities impacted by an environmental issue. [ABSTRACT FROM AUTHOR]

Cephalopod populations have expanded over recent decades, both numerically and geographically. These expansions are particularly noteworthy because cephalopods are a taxon of quickly reproducing, high-metabolic rate predators that can have disproportionate impacts on naïve ecosystems. We report a new occurrence of an octopus species in 11.6 m of water in Burrows Bay, Washington, USA (coastal northeast Pacific Ocean). These newly identified individuals have several characteristics that clearly differentiate them from either of the two known octopus species that occur in shallow water within the area: Octopus rubescens and Enteroctopus dofleini. Instead, specimens superficially resemble Muusoctopus leioderma , a species which is found in the geographic area, but has never been reported at depths less than 70 m. Octopuses were collected for morphological and genetic comparison to known octopus species, focusing on other nominal Muusoctopus species. Genetic comparisons were conducted using three mitochondrial loci (12S ribosomal RNA, cytochrome oxidase subunit III, and cytochrome b) sequenced for the octopus along with two M. leioderma museum specimens, including the species' neotype. Observation of octopus behaviour revealed a unique burrowing behaviour. Morphology of the octopus found in Burrows Bay largely coincides with M. leioderma , with a few notable differences. Phylogenetic analysis revealed that Burrows Bay octopus forms a monophyletic clade with the M. leioderma neotype, but also suggested that M. leioderma is more closely related to Octopus californicus than to the other members of the genus Muusoctopus. These octopuses are thus attributed to M. leioderma but the generic placement of the species should be reviewed. [ABSTRACT FROM AUTHOR]

Graceful kelp crabs (Pugettia gracilis) are abundant consumers in shallow subtidal ecosystems of the Salish Sea. These dynamic habitats are currently experiencing multiple changes including invasion by non-native seaweeds and ocean warming. However, little is known about P. gracilis’ foraging ecology, therefore we investigated their feeding preferences between native and invasive food sources, as well as feeding rates at elevated temperatures to better assess their role in changing coastal food webs. To quantify crab feeding preferences, we collected P. gracilis from San Juan Island, WA and conducted no-choice and choice experiments with two food sources: the native kelp, Nereocystis luetkeana, and the invasive seaweed, Sargassum muticum. In no-choice experiments, P. gracilis ate equal amounts of N. luetkeana and S. muticum. However, in choice experiments, P. gracilis preferred N. luetkeana over S. muticum. To test effects of temperature on these feeding rates, we exposed P. gracilis to ambient (11.5 ± 1.3 °C) or elevated (19.5 ± 1.8 °C) temperature treatments and measured consumption of the preferred food type, N. luetkeana. Crabs exposed to elevated temperatures ate significantly more than those in the ambient treatment. Our study demonstrates the diet flexibility of P. gracilis, suggesting they may be able to exploit increasing populations of invasive S. muticum in the Salish Sea. Warming ocean temperatures may also prompt P. gracilis to increase feeding, exacerbating harmful impacts on N. luetkeana, which is already vulnerable to warming and invasive competitors.

Extreme water-level recurrence estimates for a complex estuary using a high-resolution 2D model and a new method for estimating remotely generated sea level anomalies (SLAs) at the model boundary have been developed. The hydrodynamic model accurately resolves the dominant physical processes contributing to extreme water levels across the Washington State waters of the Salish Sea, including the relative contribution of remote SLA and other non-tidal residual processes that drive extreme water levels above the predicted tide. The model’s predictions have errors of less than 15 cm (2 = 0.76). The hydrodynamic model simulations using the remote SLA predictor compared well with simulations using the widely used data-assimilative global ocean model HYCOM SLA data (root mean square difference of 5.5 cm). Extreme water-level recurrence estimates with and without remote SLA show that remote forcing accounts for 50–60% of the total water level anomaly observed along Salish Sea shorelines. The resulting model simulations across decadal timescales provide estimates of extreme water level recurrence across the Salish Sea, capturing climate variability important to long-term coastal hazard planning. This approach has widespread applications for other complex estuarine systems.

Anecdotal and quantitative evidence of the Cougar's (Puma concolor) ability to swim across large bodies of water remains limited in the scientific literature. Here we report a 1.1-km swim by a dispersing male Cougar from the Olympic Peninsula to Squaxin Island in Puget Sound, Washington. We then predict the total number of islands in the Salish Sea that may be accessible to Cougars via swimming, using this Cougar's movement as a potential upper threshold distance, and present sightings records from islands in the Salish Sea to confirm or refute our results. We estimated that 3808 of 6153 islands in the Salish Sea could be accessible to Cougars with ≥1 or more 1.1-km swims, and we confirmed Cougar presence on 18 of those islands. Four islands with confirmed sightings required swims closer to 2 km. Increasing the threshold distance to 2 km yielded an additional 775 potentially accessible islands, including the 4 not captured by the 1.1-km threshold. Cougars are an umbrella species used to identify wildlife corridors across their range. We believe that improving our understanding of Cougar swimming abilities will aid us in determining the extent of habitat connectivity existing in the Pacific Northwest, where current habitat fragmentation characteristic of the Anthropocene may threaten Cougar metapopulation connectivity important to maintaining genetic health of the species. [ABSTRACT FROM AUTHOR]

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Based on records dating from 1859 to 2021, we provide an overview of the marine animal diversity reported for Galiano Island, British Columbia, Canada. More than 650 taxa are represented by 20,000 species occurrence records in this curated dataset, which includes dive records documented through the Pacific Marine Life Surveys, museum voucher specimens, ecological data and crowd-sourced observations from the BC Cetacean Sightings Network and iNaturalist.We describe Galiano Island's marine animal diversity in relation to the Salish Sea's overall biodiversity and quantify the proportional contributions of different types of sampling effort to our current local knowledge. Overviews are provided for each taxonomic group in a format intended to be accessible to amateur naturalists interested in furthering research into the region's marine biodiversity. In summary, we find that the Pacific Marine Life Surveys, a regional community science diving initiative, account for 60% of novel records reported for Galiano Island. Voucher specimens account for 19% and crowd-sourced biodiversity data 18% of novel records, respectively, with the remaining 3% of reports coming from other sources. These findings shed light on the complementarity of different types of sampling effort and demonstrate the potential for community science to contribute to the global biodiversity research community. We present a biodiversity informatics framework that is designed to enable these practices by supporting collaboration among researchers and communities in the collection, curation and dissemination of biodiversity data.

Abstract Coastal Indigenous communities that rely on subsistence harvests are uniquely vulnerable to declines in nearshore species. The basket cockle Clinocardium nuttallii is among the favored foods of Indigenous people along the northwest Pacific coast of North America, yet localized declines in their abundance have led to interest in stock enhancement efforts. We used a population genomics approach to examine potential risks associated with stock enhancement of C. nuttallii in the southern Salish Sea, a large inland estuary that includes Puget Sound. More than 8000 single nucleotide polymorphisms across 349 individuals at 12 locations were assembled de novo using restriction site‐associated DNA sequencing. Results indicated that C. nuttallii within the southern Salish Sea were distinct from those along the outer Pacific coast (FST = 0.021–0.025). Within the southern Salish Sea, C. nuttallii populations appear to be well‐connected despite numerous potential impediments to gene flow; Hood Canal, which experiences the lowest flushing rates of all Puget Sound sub‐basins, was a minor exception to this strong connectivity. We found evidence of isolation by distance within the southern Salish Sea, but the slope of this relationship was shallow, and FST values were low (FST = 0.001–0.004). Meanwhile, outlier analyses did not support the hypothesis that southern Salish Sea sub‐populations are locally adapted. Estimates of effective population size had no upper bound, suggesting potentially very high adaptive capacity in C. nuttallii, but also making it difficult to assess potential reductions in effective population size resulting from stock enhancement. We present several strategies to augment cockle populations for subsistence harvest that would limit risk to the genetic diversity of wild cockle populations.

Seagrass meadows are complex, multi-species ecosystems that are facing increasing seawater temperatures with climate change. Previous experimental studies have imposed relatively short-term elevated seawater temperatures for understanding stress tolerance and have revealed a disparate range of responses by the seagrasses themselves, as well as by organisms that inhabit seagrass meadows. Variation in response may be due to differences in environmental context, population-level characteristics, temperature regime, and metrics investigated. To tease apart environmental versus intrinsic population factors, we conducted a 'common garden' experiment with eelgrass (Zostera marina L.) from four populations of the greater Puget Sound region (Washington, USA) to test effects of slightly elevated seawater temperatures (+2.5 °C or + 5.6 °C compared to ambient) over long durations (1–2 years), to emulate shifts in mean temperature as predicted for climate change. We measured a comprehensive suite of demographic and morphological traits to be inclusive of traits measured amongst other studies, as well as wasting disease and epiphyte characteristics. We found that, under elevated temperatures, Z. marina exhibited enhanced response or trade-offs in demographic and morphological characteristics depending on season, magnitude of temperature increase, duration of elevated temperature, and donor population. Under +2.5 °C conditions, Z. marina exhibited primarily enhanced responses, such as production and maintenance of longer leaves year-round, and more, wider leaves and increased shoot production during spring. Under +5.6 °C conditions, aboveground morphological responses were even more enhanced and lasted longer, but with trade-offs with shoot production and maintenance of leaf tissue during winter months, and only in the first year. By the second year of exposure to +5.6 °C conditions, plants were not able to maintain increased shoot production rates. These results suggest Z. marina response to slightly elevated temperatures may be modulated by seasonal light availability, so enhanced responses may be only temporary and could precede longer-term decline within a small margin of temperature increase if conditions persist >1 year. Additionally, treatment-by-site interactions did occur, under higher elevated temperature conditions, suggesting resilience may vary by ecotype. Lastly, plants in heated treatments had fewer epiphytes and exhibited seasonal differences in eelgrass wasting disease, suggesting seawater warming could impact eelgrass meadows as whole ecosystems. Further research is needed to understand how these responses may differ across latitudinal gradients, temperature regimes, and multi-species assemblages, and also implications for carbon cycling and habitat provisioning ecosystem functions of eelgrass meadows. • Zostera marina response to prolonged seawater warming differed by season • Z. marina ecotypes varied in demographic and morphological response to warming • Elevated water temperatures affected host-pathogen and epiphyte-grazer interactions [ABSTRACT FROM AUTHOR]

Monitoring the spatial distribution and seasonal dynamics of phytoplankton functional types (PFTs) in coastal oceans is essential for understanding fisheries production, changes in water quality, and carbon export to the deep ocean. The launch of new generation ocean color sensors such as OLCI (Ocean Land Color Instrument) onboard Sentinel 3A provides an unprecedented opportunity to study the surface dynamics of PFTs at high spatial (300 m) and temporal (daily) resolution. Here we characterize the seasonal dynamics of the major PFTs over the surface waters of the west coast of Canada using OLCI imagery and Chemical Taxonomy (CHEMTAX, v1.95) software. The satellite-based approach was adapted from a previously proven Empirical Orthogonal Function (EOF)-based algorithm by using a local matchup dataset comprising CHEMTAX model output and EOF scores derived from OLCI remote sensing reflectance. The algorithm was developed for the following PFTs: diatoms, dinoflagellates, dictyochophytes, haptophytes, green algae, cryptophytes, cyanobacteria, raphidophytes, and total chlorophyll-a (TChla) concentration. Of these PFTs, first level evaluation of the OLCI-derived retrievals showed reliable performance for diatoms and raphidophytes. The second level of validation showed that TChla had the best performance, and green algae, cryptophytes, and diatoms followed seasonal trends of a high temporal resolution in situ CHEMTAX time-series. Somewhat reduced correspondence was observed for raphidophytes. Due to their low contribution to the phytoplankton community (26%) and low range of variation, weak performance was noted for haptophytes, dictyochophytes, cyanobacteria, and dinoflagellates. The EOF-based PFT maps from daily OLCI imagery showed seasonal spring and fall diatom blooms with succession from spring blooms to high diversity flagellate dominated summer conditions. Furthermore, strong localized summer raphidophyte blooms (Heterosigma akashiwo) were observed, which are a regionally important harmful species. Overall, this study demonstrates the potential of the OLCI in deriving the surface dynamics of major PFTs of the Strait of Georgia (SoG), a critical habitat for the juvenile Pacific Salmon.

Garry oak (Quercus garryana) and associated ecosystems (GOAE) are culturally and ecologically significant landscapes home to over 100 Species at Risk. With less than 5% of their original extent remaining in Canada, GOAE require urgent attention to guide management of remnant habitats and protect them from ongoing cumulative threats. The loss of top predators has played a large role in a trophic cascade where hyperabundant black-tailed deer (Odocoileus hemionus columbianus) are reshaping plant and animal communities, even within protected areas. The impacts of deer browsing on plant communities is well-documented; however, the impact on pollinators that are essential for the restoration and conservation of GOAEs is still unknown. We tested the hypothesis that deer browsing has an indirect impact on bumblebee populations through their direct negative impact on floral communities. We surveyed deer density, floral communities, and bumblebee abundances across ten islands with differing levels of deer presence in the Salish Sea. We found that deer had a negative effect on the abundance of flowering plants, with an even greater effect on native species that bumblebees rely on for foraging. Deer presence had an indirect negative impact on female bumblebee abundances through the depletion of floral resources. Deer also had a negative impact on male bumblebee abundances, potentially caused by lowered colony success over the season on islands with less floral resources. These findings highlight the importance of immediate deer management to prevent the loss of native pollinators and further, potentially irreversible, ecological degradation of GOAEs.

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]

Diurnally biased monitoring and research dominate our ecological understanding and guide conservation and management decisions regarding important indicator sea duck species, such as Surf Scoters (Melanitta perspicillata). Advances in telemetry technology are improving our ability to track wildlife across the entire 24-hr day. Using location data derived from birds with surgically implanted satellite transmitters and habitat layers within a GIS (geographic information system), we analyzed Surf Scoter location data to (1) estimate movement distances between diurnal and nocturnal sites, (2) assess differences in environmental conditions at diurnal and nocturnal use locations, (3) evaluate the environmental conditions influencing nocturnal habitat selection, and (4) develop a predictive model to estimate likely nocturnal resting areas across the Salish Sea, which is composed of the inland marine waters of British Columbia, Canada, and Washington State. Surf Scoters in the Salish Sea traveled an average of 4,287 m between diurnal and nocturnal habitats, but distances varied regionally. We found that distance to shore, water depth, tidal current, and vessel traffic influenced nocturnal habitat use. Surf Scoter nocturnal use sites were characterized by greater distances from shore and deeper water than diurnal locations, although scoters avoided areas with strong tidal currents and heavy shipping traffic at night. The Salish Sea is experiencing increased ship traffic from multiple U.S. and Canadian ports. Oil tanker and shipping container vessel traffic pose a potential threat to nocturnal scoter flocks aggregating in deeper water adjacent to and sometimes overlapping with shipping lanes in narrow, glacial-carved channels of the Salish Sea. Current oil spill response plans in Washington State waters utilize diurnal distribution data, lacking important nocturnal use data. Our findings provide critical nocturnal habitat use information that can improve oil spill response policy and highlight the importance of elucidating nocturnal ecology for marine vertebrate species. [ABSTRACT FROM AUTHOR]

This paper contributes to analysis of missions of environmental non-government organizations (ENGOs) in environmental stewardship. The literature identifies a diversity of roles including tension between ENGOs working directly with government to participate in decision making processes and exerting influence on government through public education and direct action. We offer additional insights and note a shift in missions over time by reporting on a case study of missions and activities of environmental non-governmental organizations (ENGOs) focusing on the conservation and protection of the transboundary waters of the Salish Sea marine environment. The case study is based on a survey of 119 ENGO websites and interviews with 17 environmental ENGO leaders. We note growing awareness of the value of efforts in education and strategic communication initiatives, both internally and externally, and comment on challenges with transboundary collaborations. We propose opportunities for better coordination, notably across the international border. We also call for investment in communities of practice to support, among other things, awareness-raising and communication, data sharing, and advancing the role of creativity and the arts to foster environmental stewardship. [ABSTRACT FROM AUTHOR]

Marine ecosystems on continental shelves face multiple challenges due to anthropogenic disturbances, many of which can change the seawater stoichiometry (C:N:P) and consequently elemental ratios of phytoplankton. This change in food quality may not be tolerated by all grazers and predators. Gelatinous and soft-bodied zooplankton (GZ) might be more resilient to such changes. We sampled GZ species in neritic and oceanic waters of the Northeast Pacific off British Columbia, Canada, determined their phosphorus (P) content and elemental ratios (C/P, N/P), and analysed intraspecific variability associated with size and ontogeny. P content was measured for twelve GZ taxa. P % DW (dry weight) decreased with size for the hydrozoan Aequorea sp., scyphozoans Aurelia labiata, Cyanea capillata, and the thaliacean Salpa aspera, and differed significantly for two development stages of the salp S. aspera. While C/P and N/P were mostly size and stage independent, they were highly variable. C/P values of GZ were generally higher than values of crustacean zooplankton, indicating that GZ represent poor-quality prey for non-GZ predators, and that GZ may have a higher resilience towards P-limited (low quality) prey. Changing ocean conditions and nutrient stoichiometry of prey may favour GZ, although large variability in P dynamics among GZ taxa and uncertainty about future ocean stoichiometry changes make generalisations difficult. [ABSTRACT FROM AUTHOR]

How birds use and interact with an urban environment has been of interest for a variety of species across the globe. This has particularly been the case for gulls (Laridae) as species in this family nest and otherwise occupy habitat in urban areas on six continents, often coming into conflict with humans as they do so. In this study, we combine survey data of urban-nesting Glaucous-winged Gulls Larus glaucescens in Vancouver, Canada with detailed information on architectural and spatial features of the structures on which they nest to build an explanatory and predictive statistical model for nest-site selection in our study city. We find that building height is by far the most important explanatory variable in this selection process and that rooftops of higher structures are generally more attractive to nesters, but only up to a certain point. Flat rooftops in non-residential areas that are near water are also highly valued. However, complex relationships exist between these and other variables that offer detailed insights into urban nesting patterns. We use our modelling approach to predict that roughly 1,800 pairs of Glaucous-winged Gulls nested in the city in 2017 and over 2,000 pairs nested in the city in 2023. Combining this with high exact nest and rooftop recurrence rates derived from additional survey data taken between 2015 and 2019, and with historical population data, we argue that this urban population is likely to continue to expand in the near future at roughly 4% per annum. As this species has suffered declines in its natural breeding colonies across the region, this suggests its future in the region may be increasingly urban-centric. • Field observations combined with building features to predict urban nesting via GAMs. • Roughly 2000 pairs of Glaucous-winged Gulls nest across the City of Vancouver, Canada. • This urban population is growing at a rate of roughly 4% per annum. • Nest site fidelity is approximately 80%–90% per annum. • Building height is the most important built feature that predicts nest occurrence. [ABSTRACT FROM AUTHOR]

Coastal Indigenous communities that rely on subsistence harvests are uniquely vulnerable to declines in nearshore species. The basket cockle Clinocardium nuttallii is among the favored foods of Indigenous people along the northwest Pacific coast of North America, yet localized declines in their abundance have led to interest in stock enhancement efforts. We used a population genomics approach to examine potential risks associated with stock enhancement of C. nuttallii in the southern Salish Sea, a large inland estuary that includes Puget Sound. More than 8000 single nucleotide polymorphisms across 349 individuals at 12 locations were assembled de novo using restriction site‐associated DNA sequencing. Results indicated that C. nuttallii within the southern Salish Sea were distinct from those along the outer Pacific coast (FST = 0.021–0.025). Within the southern Salish Sea, C. nuttallii populations appear to be well‐connected despite numerous potential impediments to gene flow; Hood Canal, which experiences the lowest flushing rates of all Puget Sound sub‐basins, was a minor exception to this strong connectivity. We found evidence of isolation by distance within the southern Salish Sea, but the slope of this relationship was shallow, and FST values were low (FST = 0.001–0.004). Meanwhile, outlier analyses did not support the hypothesis that southern Salish Sea sub‐populations are locally adapted. Estimates of effective population size had no upper bound, suggesting potentially very high adaptive capacity in C. nuttallii, but also making it difficult to assess potential reductions in effective population size resulting from stock enhancement. We present several strategies to augment cockle populations for subsistence harvest that would limit risk to the genetic diversity of wild cockle populations. [ABSTRACT FROM AUTHOR]

Long-term monitoring enables scientists and managers to track changes in the temporal and spatial distributions of fishes. Given the anthropogenic stressors affecting marine ecosystem health, there is a critical need for robust, comprehensive fish monitoring programs. Citizen science can serve as a meaningful, cost-effective strategy to survey fish communities. We compared data from 13,000 surveys collected over 21 years (1998–2019) by Reef Environmental Education Foundation (REEF) volunteer divers to a published compilation of Salish Sea ichthyofauna collected using an assortment of methods. Volunteer divers observed 138 of 261 recognized species in the Salish Sea, expanded the range of 18 species into additional Salish Sea sub-basins, and identified one species novel to the Salish Sea (Gibbonsia metzi — Striped Kelpfish). To identify Salish Sea fish species that are most suitable to be monitored by underwater visual census and to evaluate confidence in in situ identification, we developed a categorization system based on the likelihood of recreational divers and snorkelers encountering a given species, and on whether identification required a specimen in hand or could be classified to species visually (with or without a high-quality photograph). REEF divers encountered 62% (138 of 223) of the visually detectable species occurring in the region and 85% (102 of 120) of species most likely to be observed by recreational divers. Our findings show that citizen scientists provide valuable monitoring data for over half of the 261 marine and anadromous fish species known to occupy the Salish Sea, many of which are not routinely monitored otherwise. [ABSTRACT FROM AUTHOR]

Based on records dating from 1859 to 2021, we provide an overview of the marine animal diversity reported for Galiano Island, British Columbia, Canada. More than 650 taxa are represented by 20,000 species occurrence records in this curated dataset, which includes dive records documented through the Pacific Marine Life Surveys, museum voucher specimens, ecological data and crowd-sourced observations from the BC Cetacean Sightings Network and iNaturalist. [ABSTRACT FROM AUTHOR]

The foundational objective of conservation science is to maximize benefits to people and to biodiversity, but ensuring research translates into conservation action is not straightforward. We, retrospectively, evaluated nearly 20 years of small‐scale, competitively funded research to identify parameters most closely associated with science that produced conservation benefits. All projects were funded to help improve the health of marine and coastal flora and fauna within the Salish Sea but only 40% resulted in a positive conservation outcome. Analysis showed that projects that collaborated with personnel from government agencies, and prioritized networking and stakeholder engagement before, during and after the research, were more likely to result in a conservation action. Publication of a peer‐reviewed article did not increase the chance of success. Credible research that includes government collaborators and prioritizes networking and stakeholder engagement increases the probability that scientific findings will inform conservation management. [ABSTRACT FROM AUTHOR]