Pacific herring (Clupea pallasii) play a critical ecological role in the Puget Sound food web and are experiencing declines throughout the Sound. Presently, no single cause has been identified, and consequently, no policy action has been implemented to reverse the declines. Here we evaluate the hypothesis that terrestrial landscape features govern the trends in local stocks (defined by aggregations during reproduction) through run-off, noise, light, and other indirect effects. We predicted that status of local stocks would show associations with terrestrial landscape features such as land use and human density. To test these predictions, we gathered a time series of spawning biomass estimates for sub-stocks throughout Puget Sound and used multiple metrics to evaluate the population status of each subpopulation. We then related these metrics with information on local land-use and other localized anthropogenic disturbances. Across all metrics, a majority of the 22 stocks showed impaired status over the past 15 years. However, we found no association between local status and landscape metrics. This result indicates that landscape level effects are not solely responsible for the impaired status of Pacific herring, but we caution that this may be because there are multiple, interacting causes for declines that need to be addressed to recover this valuable species.

Pacific sand lance (PSL) are a pelagic plankton feeding forage fish that also exhibit benthic associated behavior, related to burial in sediment on the ocean floor. They represent a key trophic link between plankton and upper-level predators. Despite their ecological importance, these fish are relatively under researched. This study provides new insights related to sediment preference and the effects of light availability on foraging behavior, and quantifies movement patterns related to various response behaviors. We found that PSL may prefer sediments made up of fine and coarse grain sand, as well as require a light cue to leave sediment habitats and forage. Additionally, we quantified a multitude of behaviors exhibited in PSL and found statistically significant relationships therein. We observed positive correlations between fish length and velocity in schooling fish and in fish movement related to burial in sediment. We also observed a negative correlation between fish length and both burial depth and steepness of body position within sediments (burial angle). In short, longer fish were generally faster and buried deeper within sediment at a flatter angle. Schooling distances were compared through two methodologies: stereo camera and video imaging analyses. A significant difference was found between the two, likely due to human error. Further research should be conducted on sediment preference as it relates to spatial habitat, as well as other behavior motion and schooling analysis.

In biomimetics, nudibranch sea slugs serve as a model for suction technology suited for rough and uneven surfaces. This study quantified and compared the attachment strengths of several nudibranch species [Dirona pellucid (n=12), Janolus fuscus (n=23), Hermissenda crassicornis (n=20), Aeolidia papillosa (n=13)] from the rocky intertidal of the San Juan Islands (SJI), WA on 3 different substrates – rough rock, smooth rock, and a plank of bull kelp. In individual trials, the substrate and each sea slug were placed in a mini flume tank (0.02 m³ volume) with a rotor engine generating a known current velocity to simulate wave exposure. Water velocity was increased in a stepwise manner (increments of 0.025 m/s to a maximum of 0.25 m/s) until the nudibranch fell from the substrate (referred to as the Critical Point Force, CPF) or until the full trial period (10 mins) elapsed. The hydrodynamic force on the nudibranch was calculated assuming negligible body mass and used as a proxy for nudibranch attachment force, standardized according to nudibranch body length. Attachment strengths were cross compared to calculated average hydrodynamic force in the SJI according to ocean current velocities obtained from NOAA. D. pellucid was the only species to have significantly greater CPF than the other 3 species. Few H. crassicornis individuals fell (n=3), so their CPF could not be accurately quantified. Estimated average hydrodynamic force for SJI currents on a model nudibranch was 56.4 mN while average experimental nudibranch CPF was 5.06 mN. This difference may be due to higher water velocities in the SJI channel than at the dock where the nudibranchs were collected. Across all trials, 54% of nudibranchs fell, so further research should incorporate experimental water velocities exceeding 0.25 m/sec. No significant difference in each species’ CPF across the varied substrates was detected, highlighting nudibranchs’ potential versatility in biomimetics.

Microplastics (plastics < 5mm) are increasingly prevalent in marine systems and of growing concern, as a source of marine pollution and in potential biomagnification in food webs. This has consequences for high trophic level consumers, including humans. Despite being an emerging area of study with many unknowns, there is increased interest in understanding the abundance and consequences of marine plastics, given evidence that links plastics to degraded ecosystem and organismal health. Microplastics contain and can absorb harmful chemicals, which may serve as endocrine disruptors. This may have implications for growth, reproductive health and longevity. To expand current knowledge on Salish Sea microplastics, I processed and examined 233 Pacific sandlance, sculpin, Pacific salmon, and Arctic cod stomachs for microplastics. 28% of all fish stomachs contained at least one microplastic particle. There was variation of prevalence between sites, ranging from 3% to 49%. Differences between prevalence of plastics differed between beach sites for both sandlance and sculpin and also differed from sandlance sampled in offshore benthic habitats. All forage and benthic samples indicated potential biomagnification to salmon based off of biomagnification factor values (BMF). Comparisons between plastic concentrations and stomach fullness was compared with plastic concentration. Further investigation is needed to develop a more thorough understanding of the microplastic issue in the San Juan Archipelago

Scripps’s murrelets (Synthliboramphus scrippsi; hereafter murrelets) are an endangered seabird with one of the largest breeding colonies in the U.S. at Anacapa Island within Channel Islands National Park. Recent monitoring on Anacapa Island has revealed predation of adult murrelets by common ravens (Corvus corax) that target incubating individuals at their nests. Murrelets are long-lived seabirds, which suggests that adult survival is an important demographic parameter for the viability of this population. Our study will determine the efficacy of remote monitoring tools to detect predation events, predator visitation, and murrelet activity. We deployed camera traps and autonomous recording units (ARUs) at five known nesting caves during the 2021 breeding season. We will compare predator visitation and predation events captured on camera traps with acoustic data from the ARUs to determine the extent of predator vocalization; the same will be done to capture murrelet activity. ARU and camera trap detections will be compared to traditional monitoring methods where humans perform tri-weekly nest checks for predation evidence such as murrelet carcasses or feather piles. We anticipate camera traps will perform better than ARUs at detecting predator visitation and predation events, but groups of two or greater ravens will have higher vocalization rates. In contrast, we anticipate that ARUs will perform better than camera traps at detecting murrelet activity due to their small stature making them less likely to trigger the cameras. We hypothesize the combined power of both remote monitoring tools may be comparable to traditional monitoring methods. Our comparative analysis of monitoring methods will allow park management to make informed decisions for future monitoring protocols for murrelets. In addition, our results will provide the park with a better understanding of the impact of raven predation on murrelets as well as management options to mitigate this impact.

Rorqual whales are some of the largest animals on the planet, yet feed on some of the smallest animals in the ocean. When feeding, rorquals will lunge toward dense masses of food, engulfing both prey and water. Their upper jaws are lined with baleen – a filtering fringe composed of keratin plates and bristle-like hairs. Larger keratin plates (major) are situated labially with smaller plates (minor) lingual to them. Rorquals can feed on plankton, like krill, and fish. We hypothesize that baleen morphology varies with species and diet. We investigated the hierarchical anatomy of baleen in five whale species: humpback, fin, gray, blue and minke – which span a great range in body and prey size. We used computed tomography (CT) and scanning electron microscopy (SEM) to image, quantify, and understand how variability in baleen morphology may affect filtration. CT revealed cylindrical keratin hairs embedded in the baleen plates that grow out of the gum. These hairs extend out of the ventral side creating a fringe. The size of the hairs, the keratin sheath surrounding each hair, and the keratin matrix of the baleen plates vary by species. SEM revealed that the keratin plates are worn away at the ventral side exposing the bristles by peeling away the exterior layers. Hair diameter differs within an individual plate for each of the species. Hair diameter varies with species, but does not correlate with whale body size i.e. bigger whales do not have thicker hairs.

Prochlorococcus is a cyanobacterium smaller than 1 μm that accounts for much of the primary production in nutrient-poor areas such as the North Pacific Subtropical Gyre (NPSG). In the transition from the NPSG to more productive coastal regions, there are fronts that have sharp changes in chemical, physical, and biological properties. In more coastal, nutrient-rich conditions, larger phytoplankton are more abundant, including Synechococcus and picoeukaryotes. Data previously collected on cruises going north from the NPSG (the Gradients cruises) were compared to data I collected on the TN398 cruise going east from the NPSG to the California coast. A SeaFlow flow cytometer measured small phytoplankton, including Prochlorococcus, Synechococcus, and picoeukaryotes. Prochlorococcus was most abundant in nutrient-poor conditions in the NPSG, reaching a concentration of 300 cells/μL, and larger phytoplankton, including Synechococcus and picoeukaryotes, were most abundant in the coastal ocean and subpolar region. The diameters of Prochlorococcus, Synechococcus, and picoeukaryotes varied on a diel cycle that was most strongly observed in the gyre. The average diameter of Prochlorococcus and Synechococcus increased by about 0.2 μm outside the NPSG, while the diameter of picoeukaryotes observed by SeaFlow decreased by about 0.4 μm. Prochlorococcus abundance was negatively correlated with nitrate and nitrite. In the future, these variables could be compared seasonally, annually, and across ocean basins to better understand how these populations are responding to climate change.