Recent csgc items

Navigating Shallow Streams: Effects of Changing Stream Water Depths on Outmigration of Endangered Coho Salmon

Fri, 31 Jul 2026 00:00:00 +0000

Declining streamflow from water management and climate change threatens fish migration. In coastal California, USA, we evaluated the effects of receding streamflow on the seaward migration of juvenile Coho Salmon (Oncorhynchus kisutch) in four streams over 10 years (2010–2020). We monitored the movement of juveniles tagged with passive integrated transponders and measured depths at riffle crest thalwegs (RCTs), the shallowest channel feature that fish must navigate. Each stream exhibited a unique relationship between RCT depth and flow, relating to its geomorphic characteristics, producing distinct ranges of water depths among streams. During the peak migration period, juveniles moved over a wide range of depths (interquartile range 5.8–19.2 cm), with greater depths occurring in wet years than in dry years. However, the depths at which fish were detected were significantly deeper than continuous, observed depth measurements during the same period. We found the greatest differences...

Global priorities for ocean sustainability from Early Career Ocean Professionals.

Fri, 31 Jul 2026 00:00:00 +0000

Intergenerational diversity is central to achieving long-term ocean sustainability. As such, one of the main goals and challenges in the UN Decade of Ocean Science for Sustainable Development (2021–2030) is fostering engagement and leadership across career stages and from diverse sectors. To understand the knowledge and professional development needs of the next generation, we surveyed the perspectives of 1344 Early Career Ocean Professionals (ECOPs) across 108 countries and territories. We assess the survey results, reflect on what has been done to address these needs halfway through the Ocean Decade, and suggest areas to further progress. We found that climate change and its social and ecological impacts are the unifying topical priority for ECOPs globally. ECOPs called for support and access to professional development. Despite progress in many initiatives, enhanced opportunities for collaboration across disciplines and sectors, mentorship and professional development, knowledge...

Predicting Shoreline Changes Along the California Coast Using Deep Learning Applied to Satellite Observations

Fri, 31 Jul 2026 00:00:00 +0000

Understanding and predicting changes in shoreline location are critical for coastal planners. In situ monitoring is accurate but not widely available. Satellite observations of shorelines have global coverage, but their accuracy and predictive capacity have not been fully explored. Abundant beach surveys and extensive wave observations in Southern California provide a unique ground truth for the interpretation of satellite-derived recently wetted waterlines. We combine 23 years of waterline position estimates from satellite imagery with nearshore wave hindcasts and tides to train and test a deep neural network (DNN). The trained DNN uses only tides and waves as predictors at transects with satellite coverage and wave estimates to predict beach width and, for the first time, seasonal average beach slopes. Beach width changes hindcast using DNN have at least fair skill (>0.3) for 50% of transects, where the skill was calculated relative to the mean of extensive new in situ survey...

Lessons learned from the PICES FUTURE Program on development of an interdisciplinary international science program to advance ocean sustainability.

Fri, 31 Jul 2026 00:00:00 +0000

Interdisciplinary international science programs that combine environmental, ecological, and social research are pivotal in advancing ocean sustainability by integrating diverse expertise and fostering collaboration across borders. We examine the evolution and accomplishments of the North Pacific Marine Science Organization’s (PICES) Forecasting and Understanding Trends, Uncertainty and Responses of North Pacific Ecosystems (FUTURE) Program, designed to understand and communicate the future of North Pacific ecosystems under various natural and anthropogenic forces. The program’s unique application of the North Pacific Social-Ecological-Environmental Systems (SEES) framework has aimed to facilitate interdisciplinary collaboration and enhance our comprehension of ecosystem responses to climate variability. Through a combination of systematic review and quantitative text analysis of research outputs, we evaluate the program’s success in addressing its scientific objectives, and identify...

Living in the ‘Blue Zone’ of a sea-level rise inundation map: Community perceptions of coastal flooding in King Salmon, California

Fri, 31 Jul 2026 00:00:00 +0000

As sea-level rise (SLR) inundation maps proliferate, it is important to study their politics – both how they are created and how they act upon and shape various lives and places. This paper uses the example of King Salmon, CA – a rural, low-income residential area projected to be one of the most at risk to SLR on the US West Coast – to examine how a community responds to external projections showing SLR risk to their homes and businesses. Through interviews with 17 King Salmon community members and observation of a county-hosted ‘communities at risk’ workshop, we examined the community’s social context, their past experiences with flooding, and their reaction to SLR projection maps including what next steps they would like to see taken. Residents expressed a strong connection to the place, noting that it is one of the few affordable places to live on the coast in California. We found that residents already live with regular flooding during larger tides of the year and have taken...

Proteinaceous deep sea coral amino acid isotope records reveal climate-driven decadal-scale planktic ecosystem fluctuations

Fri, 31 Jul 2026 00:00:00 +0000

Decadal-scale climate variability drives important fluctuations in nutrient availability and productivity in highly productive eastern boundary current pwelling ecosystems, but the relatively brief duration of most monitoring efforts limits understanding of these dynamics. When applied to high-resolution paleoarchives such as deep-sea proteinaceous coral skeletons, stable carbon and nitrogen isotope (δ13C and δ15N) analysis can provide useful new insight into biogeochemical and ecological changes beyond the instrumental record. However, interpretation of bulk δ13C and δ15N records is often complicated by multiple possible drivers of variability. Here, we addressed these challenges by applying both bulk and compound-specific amino acid δ15N and δ13C analysis to two bamboo coral specimens from Sur Ridge on the central California margin, generating sub-decadal resolution records spanning c. 1810 to present. Our overarching goals were to first test amino acid δ13C and δ15N proxies...

A laser-equipped chamber for the assessment of sprint swimming traits in fishes

Fri, 31 Jul 2026 00:00:00 +0000

Sprint swimming performance in fishes is relatively understudied despite its critical role in predation attempts, prey evasion, spawning events, and overcoming hydraulic challenges. Sprint swimming is characterized by fast acceleration, over a short distance and of limited duration. The bulk of sprint performance research uses analysis of high-speed recordings of fish behavior. While behavioral video analysis has improved, it is still expensive in both processing time and computational resources, limiting the ability to develop reaction norms for sprint performance which necessitate large sample sizes. Here we present a laser-gated sprint performance chamber (SPC) that improves upon past designs by introducing an adjustable number of lasers (≤ 25) that facilitates greater resolution on sprint performance. Use of customized arrangements can facilitate measurement of novel performance metrics of interest to a range of key questions (e.g., fatigue rate, residual anaerobic capacity,...

Size at maturity, reproductive cycle, and fecundity of the southern California brown box crab Lopholithodes foraminatus and implications for developing a new targeted fishery,

Fri, 31 Jul 2026 00:00:00 +0000

The brown box crab Lopholithodes foraminatus is a member of the king and stone crab family (Lithodidae) that occurs in deepwater along the eastern Pacific coast. Historically, landings in California have been low for this species, but an increase in fishing pressure prompted the state to designate it as an emerging fishery and implement an experimental fishery program. With no known biological studies of California brown box crab, essential fisheries information is needed to evaluate the feasibility of a new targeted fishery.

Targeted and nontargeted approaches to uncover complex halogenated pollutants in the historically endangered California brown pelican

Fri, 31 Jul 2026 00:00:00 +0000

Historically, California brown pelicans experienced reproductive failure and population decline induced by the pesticide dichlorodiphenyltrichloroethane (DDT). Although the population recovered after the 1972 DDT ban, nontargeted analytical methods have identified over 45 DDT-related compounds (DDT+) and other typically unmonitored halogenated organic compounds (HOCs) in regional upper trophic level wildlife species, presumably originating from the persistent and chemically-complex DDT manufacturing waste deposited in the Southern California Bight (SCB). However, there is limited data on DDT+ in previously endangered bird populations, including the brown pelican. We identified 183 HOCs in seven brown pelican liver samples (131 ± 48, mean ± SD) via nontargeted analysis. Seventeen DDT+ compounds were identified, including four tris(4-chlorophenyl)methane (TCPM)-related compounds, and 17 polychlorinated terphenyls (PCTs), all of which were not assessed in prior pelican research....

Juvenile life history, migration, and habitat use of natural-versus hatchery-origin Chinook Salmon

Fri, 31 Jul 2026 00:00:00 +0000

Objectives Our overall objective was to directly compare the early life history and migration patterns of hatchery- and natural-origin fish and determine when hatchery fish provide good surrogates for natural-origin winter-run Chinook Salmon Oncorhynchus tshawytscha in the Sacramento River system. Specifically, our objectives were to compare the juvenile freshwater habitat use, residence time in freshwater habitats, and size at age and relative growth of juveniles. Methods Using otoliths that were collected from adult carcasses, we reconstructed the freshwater life history of hatchery- and natural-origin fish through microstructural and chemical analyses. We analyzed the otolith strontium isotope chemistry and daily increment widths to characterize habitat use, migration timing, and growth. Results Following their hatchery-rearing period, hatchery fish had much shorter residence times (11 d, SD = 16 d) in the river than natural-origin fish (129 d, SD = 37 d). Beyond the reduced...

Variation in Salmon Migration Phenology Bolsters Population Stability but Is Threatened by Drought

Fri, 31 Jul 2026 00:00:00 +0000

Intrapopulation variation in movement is common in nature but its effects on population dynamics are poorly understood. Using movement data from 3270 individually-marked fish representing nine cohorts of coho salmon (Oncorhynchus kisutch) in California, we show that bimodal intrapopulation variation in the timing of juvenile down-migration from their natal habitat and subsequent residence in non-natal habitat affects growth, emigration timing, and the abundance and stability of adult returns. Non-natal fish (early down-migrants) exhibited more variable growth and more variable but earlier emigration to the estuary than natal fish (late down-migrants). While natal rearing was more common, non-natal fish were overrepresented among adult returns, and total returns were 1.4 times more stable than natal returns alone. Our results demonstrate that variation in migratory behaviour bolsters population stability. However, non-natal rearing is reduced in low water years, suggesting that...

Characterizing morphology of Egregia menziesii (Laminariales) in California over 2 centuries using historical and contemporary herbarium specimens.

Fri, 31 Jul 2026 00:00:00 +0000

The canopy-forming feather boa kelp Egregia menziesii exhibits remarkable morphological variability across its geographic range. Regional morphotypes of Egregia were once considered separate species, but they were not determined to be genetically distinct; instead, their morphology was thought to reflect local physical or environmental conditions. Although morphological variation in Egregia has long been observed and was previously characterized through field surveys in the early 2000s, we revisited this topic using digital morphometrics (i.e., image analysis) of 1624 macroalgal herbarium specimens from California dating back to the 19th century. We observed that the morphology of Egregia (rachis texture, lateral blade shape, and blade or pneumatocyst density) varied along a latitudinal gradient and could be predicted by seawater temperature and wave height. We also identified some region-specific morphological changes in recent decades. Further, the monthly presence or absence...

Risky main stems are a poorly understood constraint on salmon recovery in coastal California rivers

Fri, 31 Jul 2026 00:00:00 +0000

Objective: Investment in salmon habitat restoration often focuses on natal streams, with a goal of improving access for spawning fish and increasing early life survival of juveniles. This work is justified by a large body of research; however, return on investment in natal streams (at least in terms of increased adult abundance) has, so far, been marginally successful at best. The factors that constrain salmon populations may shift in space and time, and accurately tracking these constraints requires monitoring the full spatial and temporal scope of the salmon life cycle. In particular, juvenile salmon emigration through main-stem rivers to the ocean is not well studied and is poorly understood. Low emigration survival can prevent successful upstream habitat restoration from being realized as increased adult recruitment. Methods: We present acoustic telemetry studies from two coastal California rivers to estimate seaward emigration survival of Coho Salmon Oncorhynchus kisutch...

Centering knowledge co-production in sustainability science: Why, how, and when.

Fri, 31 Jul 2026 00:00:00 +0000

Solving complex sustainability problems requires novel, creative approaches. One such approach is knowledge co-production, where individuals with diverse expertise collaborate to generate knowledge in support of transformative solutions. Although the concept is not new, there is growing interest in using knowledge co-production in sustainability science, yet relatively few resources offer a practical guide, rooted in theory, to help researchers and practitioners understand when and how to co-produce in the context of sustainability science. This paper synthesizes the existing literature across multiple disciplines to present a novel framework and actionable strategies for effective knowledge co-production in sustainability. The wheel of knowledge co-production, the conceptual framework presented, emphasizes the importance of iterative phases of building relationships, assessing available resources, involving diverse participants, considering context, and working together with...

RipScout: Realtime ML-Assisted Rip Current Detection and Automated Data Collection using UAVs

Fri, 31 Jul 2026 00:00:00 +0000

This article presents RipScout, a system for realtime rip current detection and data collection using drones equipped with machine learning (ML). No internet connection is required. RipScout achieves realtime performance by using lightweight ML models that fit the constraints of limited mobile computing re- sources with the drone controller. We compared different ML models trained to detect either one or two types of rip currents. The best model was then selected for RipScout. The system was evaluated with three ML models, with the EfficientDet D2 model achieving the highest accuracy of 93.1% for multiclass detection while maintaining realtime processing at an average speed of 17 frames per second. When a rip is detected along a flight path, the drone hovers in place and collects a video clip of a predefined length, followed by circling around the detected rip using prespecified radii and heights to collect video samples from different vantage points and elevations. An important...

Regional governance solutions for sea-level rise adaptation: Perspectives from Humboldt Bay, California.

Fri, 31 Jul 2026 00:00:00 +0000

Sea-level rise (SLR) is a complex challenge which could require the development of new special-purpose governance arrangements that allow for better coordination across jurisdictions and levels. This paper explores perspectives related to regional coordination for SLR adaptation in Humboldt Bay, California. Humboldt Bay is experiencing one of the fastest rates of SLR on the West Coast and exists in a complex regulatory environment with over 20 government entities, three Tribes, and numerous community members and groups connected to the issue. Through a mixed-methods approach that included 46 semi-structured interviews with and a survey of 107 coastal professionals connected to the Bay, we sought to capture local perspectives related to the barriers and opportunities for SLR adaptation, potential regional governance solutions for SLR, and the incorporation of community and equity considerations into SLR planning. Respondents identified several barriers including competing priorities...

The essential role of large research vessels in marine ecosystem observations and ocean sustainability.

Fri, 31 Jul 2026 00:00:00 +0000

Our understanding of marine ecosystems and ability to manage them sustainably has come from multidisciplinary observations made repeatedly over long periods of time. These long-term ecosystem observations depend on the capabilities of large research vessels, which play an essential role in the collection of global ocean observations. Research vessels serve as large, stable platforms for collecting high volume samples from the surface to the seafloor that provide uniquely valuable in situ marine ecosystem information. Additionally, they serve as mobile laboratories enabling the collection, preservation, processing, and analysis of unique samples and data, such as chemical, biogeochemical, and biological parameters. Given their capacity for, and repeated use in, collecting comprehensive marine ecosystem observations—across geology, physics, chemistry, and biology—large research vessels provide insight into long-term regional ecosystem dynamics. They also act as platforms-of-opportunity...

Sea Grant Programs Build Resilience to Coastal Climate Hazards.

Fri, 31 Jul 2026 00:00:00 +0000

Sea Grant programs across the United States and its territories are working with coastal communities to enhance their resilience to hazards and weather extremes exacerbated by climate change. Drawing on the expertise of the authors, many of whom have multiple years or decades of experience in the Sea Grant network, the article identifies five key strategies that Sea Grant programs employ to support the process of coastal hazards and extreme weather adaptation and resilience-building. The application of these strategies, most of which have their roots in the historical legacy of extension, are then illustrated through summaries of current Sea Grant activities and projects, showcasing how they have been applied in real-world situations. These strategies allow Sea Grant programs to fill a unique and valuable niche in national efforts to enhance coastal resilience. The article concludes with a discussion of emerging challenges and recommendations for strengthening Sea Grant’s capacity...

Anatomy of a range contraction: Flow-phenology mismatches threaten salmonid fishes near their trailing edge

Fri, 31 Jul 2026 00:00:00 +0000

Climate change is redistributing life on Earth, with profound impacts for ecosystems and human well-being. While repeat surveys separated by multidecadal intervals can determine whether observed shifts are in the expected direction (e.g., poleward or upslope due to climate change), they do not reveal their mechanisms or time scales: whether they were gradual responses to environmental trends or punctuated responses to disturbance events. Here, we document population reductions and temporary range contractions at multiple sites resulting from drought for three Pacific salmonids at their ranges’ trailing edge. During California’s 2012 to 2016 historic multiyear drought, the 2013 to 2014 winter stood apart because rainfall was both reduced and delayed. Extremely low river flows during the breeding season (“flow–phenology mismatch”) reduced or precluded access to breeding habitat. While Chinook (Oncorhynchus tshawytscha) experienced a down-river range shift, entire cohorts failed...

Fisheries of the Middle: Building collaborations between seafood and agriculture to revitalize and enhance mid-scale food production.

Fri, 31 Jul 2026 00:00:00 +0000

Fisheries of the Middle: Building collaborations between seafood and agriculture to revitalize and enhance mid-scale food production.

Sea level rise impacts on Coastal Access

Fri, 31 Jul 2026 00:00:00 +0000

Climate change and associated sea level rise (SLR) will have substantial impacts on coastlines worldwide, threatening beaches, infrastructure, economies, and communi- ties. In California, communities and individuals rely on the state’s public coastal access to physically reach and use the beaches and nearshore waters. Such use constitutes a key component of the state’s ocean-dependent coastal tourism and recreation sec- tor, and contributes significantly to state and local economies, coastal culture, and individual’s coastal attachment. This study investigates the impacts of SLR on coastal access, first by using geospatial tools to develop a higher resolution database of the location and elevation of coastal access sites (opportunities, amenities, and facilities, including parking) at various coastal access sites statewide. Then, using the Coastal Storm Modeling System (CoSMoS) SLR run-up model, we project the loss of coastal access opportunities due to SLR. We find that impacts...

Spatiotemporal models reveal dynamic growth patterns in US West Coast groundfish

Fri, 31 Jul 2026 00:00:00 +0000

Objective Variability in somatic growth of marine fish can affect their reproductive potential and survival and, therefore, the productivity of a population. Understanding how growth might vary among species can improve predictions of population status and responses to environmental change. Our objective was to characterize the variability in growth and body condition of groundfish species along the U.S. West Coast to support their monitoring and assessment. Methods We used geostatistical models to estimate growth rate and body condition, two interrelated traits associated with somatic growth, across space and time for nine commercially important U.S. West Coast groundfish species. We fit generalized linear mixed models with Gaussian Markov random fields to biological data collected from annual bottom trawl surveys to estimate variability at a 4- × 4-km spatial resolution. Results Our models uncover spatiotemporal variability in growth rate and body condition in all nine groundfish...

Collaborative fisheries research reveals reserve size and age determine efficacy across a network of marine protected areas

Fri, 31 Jul 2026 00:00:00 +0000

A variety of criteria may influence the efficacy of networks of marine protected areas (MPA) designed to enhance biodiversity conservation and provide fisheries benefits. Meta-analyses have evaluated the influence of MPA attributes on abundance, biomass, and size structure of harvested species, reporting that MPA size, age, depth, and connectivity influence the strength of MPA responses. However, few empirical MPA evaluation studies have used consistent sampling methodology across multiple MPAs and years. Our collaborative fisheries research program systematically sampled 12 no-take or highly protective limited-take MPAs and paired fished reference areas across a network spanning 1100 km of coastline to evaluate the factors driving MPA efficacy across a large geographic region. We found that increased size and age consistently contributed to increased fish catch, biomass, and positive species responses inside MPAs, while accounting for factors such as latitude, primary productivity,...

Artificial intelligence literacy for ocean professionals is needed for a sustainable future

Fri, 31 Jul 2026 00:00:00 +0000

Artificial intelligence literacy for ocean professionals is needed for a sustainable future

Environment-driven trends in larval abundance predict fishery recruitment in two saltwater basses

Fri, 31 Jul 2026 00:00:00 +0000

Environmental and biological factors influencing fish larvae can drive fishery cohort strength, yet larval abundance is typically a better indicator of spawning biomass. Under a changing ocean, studies that explore the relationships between environmental variables, larval abundance, and fishery recruitment remain valuable areas for ongoing research. We focus on a popular, recreational-only, multispecies saltwater bass fishery (genus Paralabrax) whose population status and recovery potential are uncertain. We resolved Paralabrax spp. larval data to species over a 54-year period (1963–2016) and used species distribution models to (i) generate and test species-specific standardized indices of larval abundance as indicators of adult stock status and fishery recruitment and (ii) evaluate long-term spatiotemporal trends in their population dynamics relative to environmental variables and climate forcing. Contrary to initial hypotheses, species-specific larval abundance predicted future...

Coastal Flood Hazard Workshop: Advancements in Bridging Scales and Disciplines for Future Risk Assessment

Fri, 31 Jul 2026 00:00:00 +0000

This workshop brought together researchers with technical expertise in predicting and evaluating coastal flood hazards and potential impacts in a changing climate with the goal of assessing state-of-the-art methods, determining knowledge gaps, and identifying future research pathways that can inform community-level flood risk and adaptation planning.

Marine Protected Areas and Fishing Community Well-Being: An Example from Statewide Socioeconomic Monitoring of the California MPA Network.

Fri, 31 Jul 2026 00:00:00 +0000

As marine protected areas (MPAs) continue to proliferate as an ocean conservation tool, it is important to understand their socioeconomic outcomes, both in the short-term following implementation and in the long-term as they become a more permanent part of the ocean landscape. This paper presents results from an effort to conduct long-term socioeconomic monitoring of commercial fishing communities in relation to California’s statewide MPA network, which was fully implemented in 2012 and consists of 124 MPAs covering 16% of state waters. To assess commercial fishing community perceptions of well-being and outcomes from the MPA network, we held virtual focus groups in 18 major port-based commercial fishing communities across California with a total of 85 participants from 2020 to 2021. Focus groups had both quantitative and qualitative components, with participants rating their fishing community and engaging in discussions on topics related to their environmental, economic, and...

SmartCS: Enabling the Creation of ML Powered Computer Vision Mobile Apps for Citizen Science Applications without Coding

Fri, 31 Jul 2026 00:00:00 +0000

It is undeniable that citizen science contributes to the advancement of various fields of study. There are now software tools that facilitate the development of citizen science apps. However, apps developed with these tools rely on individual human skills to correctly collect useful data. Machine learning (ML)–aided apps provide on-field guidance to citizen scientists on data collection tasks. However, these apps rely on server-side ML support, and therefore need a reliable internet connection. Furthermore, the development of citizen science apps with ML support requires a significant investment of time and money. For some projects, this barrier may preclude the use of citizen science effectively. We present a platform that democratizes citizen science by making it accessible to a much broader audience of both researchers and participants. The SmartCS platform allows one to create citizen science apps with ML support quickly and without coding skills. Apps developed using SmartCS...

Investigating eye lens composition for stable isotope analysis in fishes: a comparison between Chondrichthyes and Actinopterygii

Fri, 31 Jul 2026 00:00:00 +0000

Life history ecology provides a framework for understanding the complex interactions between organisms and their environments but is challenging to resolve for long-lived and migratory species. In fishes, life history is predominantly explored with stable isotope analysis (SIA) of accretionary tissues, such as otoliths. An alternative archival tissue validated for SIA in Teleosts (i.e., ray-finned fishes) is the proteinaceous eye lens and its growth layers (laminae). Here, we aim to expand the SIA of laminae to include Chondrichthyans (cartilaginous fishes; sharks, skates, rays, sawfish, and chimeras). We observe that urea in the eye lens drives patterns of elemental composition (i.e., C:N ratio) for Chondrichthyes, but the isotopic effect of urea is negligible. Teleost fishes exhibit consistent C:N ratios across eye lenses, while Chondrichthyan eye lens laminae C:N ratios decrease from the inner post-apoptotic laminae to outer pre-apoptotic laminae. After confirming the presence...

Seasonal variation and response of surf zone fish assemblages to environmental variables in the Northeast Pacific

Fri, 31 Jul 2026 00:00:00 +0000

Located at the land-sea interface, the highly dynamic sandy beach and surf zone ecosystem is one of the coastal zones used most intensely by humans (e.g., recreation, fishing, tourism). Surf zones are also important as fish habitat; however, the factors structuring fish assemblages in the surf zone are relatively understudied due to challenges associated with sampling this dynamic environment. To investigate temporal influences on surf zone fish communities, we evaluated seasonal trends in the fish assemblage and associations with environmental conditions using baited remote underwater video stations (BRUVS) at four beaches on the Northeast Pacific coast (California, USA) from July 2020 to June 2021. Our study region is characterized by strong seasonality in productivity (due to spring upwelling) and the wave climate (in response to winter storms), making it an ideal location for evaluating seasonal change in surf zone fish. We found that surf zone fish assemblages exhibited marked...

Time-varying flow-ecology relationships for an endangered fish population: Longfin Smelt in the San Francisco Estuary

Fri, 31 Jul 2026 00:00:00 +0000

Major estuaries globally are experiencing fast-paced changes in hydrology and ecosystem dynamics. However, connecting alteration of river flow regimes to estuarine fish population dynamics remains a challenge, partly due to the untested assumption that flow regimes, fish dynamics, and the resulting flow–ecology relationships are stationary (i.e., have no systematic changes in mean or variance over time). Here, we studied the endangered population segment of Longfin Smelt (Spirinchus thaleichthys) in the San Francisco Estuary, which depends on seasonal river flows to reproduce. We used extensive biomonitoring data (1980–2020) and two time-series modeling techniques, namely multivariate autoregressive state-space (MARSS) models and dynamic linear models (DLMs), to understand how population dynamics respond to interannual flow variation, and whether flow–ecology relationships have changed over time. MARSS outputs showed that population trajectories are best explained by a combination...

First controlled out of season spawning for California yellowtail (Seriola dorsalis)

Fri, 31 Jul 2026 00:00:00 +0000

The ability to control egg production and have a consistent supply of high quality eggs is critical to the commercial success of any farmed marine finfish species. Here we describe the first documented controlled spawning of California yellowtail (CYT; Seriola dorsalis). The aim for this study was to shift volitional spawning six months ahead of when natural spawning typically occurs for the species using photothermal manipulation. Over the course of one year we tracked spawning for two sibling groups of F1 generation broodstock and recorded relevant metrics for all spawn events (egg production, viability), eggs (egg and oil diameters, hatch rates), and larvae (notochord length at hatch, yolk sac volume, survival to first feeding). The first group was subjected to natural day length and temperature conditions (Natural) and produced eggs from March through October in 2023. The second group had a shifted day length and temperature regime (Controlled) designed to stimulate spawning...

Management considerations for establishing a coastal acidification monitoring system from U.S. Coastal Acidification Networks

Fri, 31 Jul 2026 00:00:00 +0000

Ocean acidification (OA), caused by the uptake of anthropogenic carbon dioxide, is a concern for ocean resource users in coastal regions where the phenomenon is compounded by variable processes. Sustained OA monitoring systems are critical for characterization of baseline ocean conditions and identification of changes and impacts to coastal ecosystems and communities. Establishing an OA monitoring network is best accomplished through iterative planning, sustained funding, and comprehensive understanding of the coastal system. This paper offers decision-making considerations for entities interested in establishing a local to regional scale OA observing system. Such considerations include which carbon system parameters can be measured in each system, which sensors and platforms will provide applicable information for interested partners, and best practices for observing data management. Because every region faces unique circumstances, we present context-specific examples of effective...

How California Sea Grant’s State Fellowship Program Fuels Careers in Coastal Conservation and Management

Fri, 31 Jul 2026 00:00:00 +0000

California Sea Grant’s State Fellowship Program, modeled after NOAA Sea Grant’s highly successful John A. Knauss Marine Policy Fellowship Program, provides hands-on experience in the planning, implementation, and management of marine, coastal, and/or watershed resource policies and programs in the state of California. The program matches graduate students who have recently completed their degrees with hosts in municipal, state, and federal agencies and in research and con- servation organizations in California for a 12-month paid fellowship. Over 300 fellows have been matched with over 40 unique hosts since its launch in 1987. Many alumni are now employed in key positions in government at the state and federal level, with 80% of participants in a given year going on to jobs in policy and/or resource management after completing their fellowships. This article provides a brief history of the program and testimonials from past fellows and hosts, and explores the program’s important...

Lessons learned from integrated long-term monitoring of a coho salmon population complex in the Russian River watershed

Fri, 31 Jul 2026 00:00:00 +0000

In California’s Russian River watershed, home to imperiled salmon and steelhead populations, an intensive long-term monitoring program plays an integral role in supporting species recovery. The program conducts life cycle and basinwide monitoring of natural- and hatchery-origin coho salmon using PIT antenna arrays, downstream migrant traps, snorkel counts, electrofishing, and spawner surveys paired with environmental monitoring. The program has also served as a foundation for targeted research by providing baseline data and monitoring infrastructure. Long-term and consistent tracking of population metrics has indicated modest but meaningful positive trends in abundance, but has also revealed unanticipated bottlenecks to population recovery, many of which are related to low streamflow. Monitoring has also revealed complex movement patterns of juveniles and adults throughout the watershed that have broadened our understanding of salmon life history diversity and the importance of...

Mobilizing ocean observations for marine ecosystem sustainability and resilience: A case study of the California Cooperative Oceanic Fisheries Investigations (CalCOFI)

Fri, 31 Jul 2026 00:00:00 +0000

The ocean is rapidly changing through warming, sea-level rise, ocean acidification, declining oxygen concentrations, and altered circulation patterns, which are reshaping marine ecosystems worldwide. These changes necessitate a complete and holistic view of affected marine ecosystems. Long-term ocean monitoring programs are crucial for understanding these changes and guiding sustainable management. The California Cooperative Oceanic Fisheries Investigations (CalCOFI)*1, initiated in 1949, is one of the world's longest-running and most comprehensive marine ecosystem observing programs. CalCOFI collects extensive ocean data across all Essential Ocean Variables in the Southern California Current four times a year (Gallo et al. 2022). This encompasses over 36 physical and chemical parameters, 2,500 biological parameters, and 50,000 environmental DNA sequences, measured simultaneously (Satterthwaite et al. 2025). These data have illuminated long-term ecosystem patterns, supported marine...

Persistent kelp forests during a massive decline reveal the importance of land-sea connectivity

Fri, 31 Jul 2026 00:00:00 +0000

A fundamental goal in ecology is to understand the drivers of stability in natural ecosystems in the face of disturbances. However, this is challenging when biotic and abiotic stressors operate simultaneously across multiple spatial scales. Such is the case for bull kelp forests (Nereocystis luetkeana) in northern California, where losses of predators combined with marine heatwaves have led to shifts from kelp forest to sea urchin barren states. However, despite the >90% loss of bull kelp forests since 2014, some patches remain. Here, we investigate the bull kelp community assemblage in these remnant patches as well as the drivers of bull kelp forest resistance. We used a combination of in situ field surveys (years 2020–2022), remote sensing data (years 2016–2022), and a laboratory grazing experiment with urchins (Strongylocentrotus purpuratus). We found that, in addition to the two dominant states (kelp forest vs. urchin barren), there is a third community state dominated...

The cross-cutting role of Ocean Decade Challenge 7 in achieving a sustainable and resilient global ocean observing system

Fri, 31 Jul 2026 00:00:00 +0000

With more than 90% of global warming occurring in the ocean, sea level rise doubling in the past 30 years, and the ever-increasing frequency and intensity of extreme events, ocean observations are essential for understanding and addressing some of these most pressing global challenges. Known observational needs can be addressed immediately by upgrading and expanding ocean observing capacity in under-observed areas such as polar regions, island nations and territories, coastal areas of developing countries, rapidly changing coastal systems, and the deep ocean. Enhancing existing and developing new cost-effective technologies for a range of user needs to maximize the reach of essential observations, supported by standardization and best practices for interoperability. Improved spatial and temporal coverage is urgently needed but also needs to be co-designed and fit-for-purpose. Democratizing access to ocean data and integrating artificial intelligence and machine learning into data...

Building bridges for ocean sustainability: The evolution and impact of the Early Career Ocean Professional (ECOP) Programme

Fri, 31 Jul 2026 00:00:00 +0000

Since its endorsement as a global network Programme in June 2021, the Early Career Ocean Professional (ECOP) Programme has been instrumental in supporting ocean professionals worldwide through funding, training, networking opportunities, and career development initiatives. Rooted in the vision of elevating diverse perspectives, the ECOP Programme fosters knowledge exchange between experienced professionals and ECOPs to promote ocean sustainability. As the UN Decade of Ocean Science for Sustainable Development (2021-2030) enters its fourth year of implementation, the ECOP Programme has grown and diversified to a formidable extent, both geographically and thematically. With over 5,200 ECOPs from 151 countries and overseas territories, the global ECOP community is currently dispersed across five regional nodes and more than 40 national hubs. This commentary brings some of the most active ECOP nodes into the limelight, amplifying their collective efforts to better understand, engage,...

Response of eelgrass (Zostera marina) to an adjacent Olympia oyster restoration project

Fri, 31 Jul 2026 00:00:00 +0000

Recent restoration efforts for the native Olympia oyster, Ostrea lurida, are commonly motivated by potential return of oyster-associated ecosystem services, including increased water filtration. The potential impact of such restoration on another species of ecological concern, eelgrass, Zostera marina, is unclear, but has been hypothesized to be positive if oyster filter feeding increases light penetration to eelgrass. For two years after construction of an oyster restoration project, we assessed the response of adjacent eelgrass (impact) compared to control and reference eelgrass beds by monitoring changes in light intensity, eelgrass shoot density, biomass, leaf morphometrics, and epiphyte load. We observed lower light intensity consistently over time, including prior to restoration, near the constructed oyster bed relative to the control and one of the reference locations. We also observed minor variations between control and impact eelgrass morphology and density. However,...

Toward social-ecological indicator integration in managing oceans and coasts.

Fri, 31 Jul 2026 00:00:00 +0000

A holistic understanding of social-ecological systems is essential to foster resilient, adaptive, and sustainable marine ecosystems and human communities. Yet, the integration of social and ecological dimensions is still developing within natural resource management, as are the indicators necessary to monitor them. In this study, we assess the integration of social and ecological indicators in marine management through a case study exploring the use of and degree of linkage between social and ecological indicators in US federal environmental and ocean resource agencies. Using a survey, we collected indicator sets or reports developed by these US federal agencies and found that 7 out of 11 total reports contained both social and ecological indicators. Within those reports, there were 333 social indicators. Only 35% (116) of the social indicators could be directly linked to commonly monitored ecological indicators. Social-ecological connections were focused on many themes, including...

Effects of Freshwater Flow and Population Connectivity on Benthic Community Dynamics in the San Francisco Estuary

Thu, 23 Jul 2026 00:00:00 +0000

Climate change and water diversions have greatly modified freshwater outflow into the San Francisco Estuary, changing the Estuary’s salinity regime. These climate- and water diversion-driven changes in salinities may have a wide range of impacts on important components of the San Francisco Estuary including the distribution of threatened/endangered species, the success of habitat restoration and the management of invasive species. Previous work has shown significant variation in the recruitment and survival of numerous species throughout the Estuary linked to freshwater outflow levels.

Readying California Fisheries for Climate Change

Mon, 18 Aug 2025 00:00:00 +0000

This document provides scientific guidance to the California Department of Fish and Wildlife (CDFW) regarding the potential impacts of climate change on California fisheries and recommendations for building resilience to buffer climatic forces. At CDFW’s request, the California Ocean Protection Council (OPC) provided funding to the Ocean Science Trust (OST) to convene an OPC Science Advisory Team (OPC-SAT) Working Group with relevant ecological, social science, and governance expertise. This guidance was prepared by OST and the OPC-SAT Working Group in partnership with CDFW, in adherence with the requirements in the OPC Staff Recommendation: “California State Fisheries Management: Current Efforts and Future Needs.” This project was developed for consideration by the California Department of Fish and Wildlife (CDFW) to help inform the state’s process to amend the Marine Life Management Act (MLMA) Master Plan. Products from this project have been submitted to CDFW for review and...

California’s Experience with Dunes and Coastal Resilience: A Synthesis Report of the 2021 Coastal Dunes for Resilience Workshop

Wed, 18 Dec 2024 00:00:00 +0000

The California Dune Science Network (Network) is a collaborative effort to expand understanding of coastal dunes and their role in building a resilient, transitional, and adaptive coast for future generations. In an effort to foster knowledge-sharing across these sites and disseminate information and lessons learned, the Network hosted a virtual Coastal Dunes for Resilience Workshop on December 8th and 9th, 2021. The workshop featured recent dune research, information about nature-based dune and resilience projects, and collaborative learning opportunities at California's pilot project and natural dune sites. It also engaged diverse perspectives on coastal resource stewardship, public access, and culturally inclusive climate adaptation approaches and how these play a role in the success of coastal dune resilience efforts.

Binational Coastal Resilience Assessment

Wed, 18 Dec 2024 00:00:00 +0000

Binational Coastal Resilience Assessment

Compartiendo la Costa: Oportunidades y estrategias para la resiliencia costera en la región San Diego-Baja California

Mon, 9 Dec 2024 00:00:00 +0000

El propósito de este documento es compartir una visión estratégica para mejorar la resiliencia costera en la región de San Diego-Baja California a través de la colaboración binacional basada en una evaluación de necesidades liderada por California Sea Grant y Climate Science Alliance.La visión de este documento identifica oportunidades clave y estrategias accionables que integran la investigación científica, el conocimiento tradicional y prácticas innovadoras para apoyar a las comunidades y ecosistemas costeros. Al fomentar asociaciones transfronterizas, expandir las capacidades de investigación y comprometer a diversos actores, este documento tiene como objetivo guiar los esfuerzos hacia un futuro más resiliente para nuestra costa compartida.

California’s Experience with Dunes and Coastal Resilience: A Synthesis Report of the 2021 Coastal Dunes for Resilience Workshop

Mon, 9 Dec 2024 00:00:00 +0000

The California Dune Science Network (Network) is a collaborative effort to expand understanding of coastal dunes and their role in building a resilient, transitional, and adaptive coast for future generations. In 2021, the Network documented at least nineteen sites in California where coastal dunes were in planning stages or had already been restored or constructed to increase resilience. The Network acknowledges that this list may be incomplete and welcomes suggestions for additional dune sites and resources. In an effort to foster knowledge-sharing across these sites and disseminate information and lessons learned, the Network hosted a virtual Coastal Dunes for Resilience Workshop on December 8th and 9th, 2021. The workshop featured recent dune research, information about nature-based dune and resilience projects, and collaborative learning opportunities at California's pilot project and natural dune sites. It also engaged diverse perspectives on coastal resource stewardship,...

EVALUATING SOCIOECONOMIC DIMENSIONS FOR A RESILIENT SHELLFISH MARICULTURE INDUSTRY IN HUMBOLDT BAY: ASSESSING THE STRENGTHS, VULNERABILITIES, AND POTENTIAL OF HUMBOLDT’S EXPANDING INDUSTRY

Mon, 9 Dec 2024 00:00:00 +0000

For nearly 90 years the shellfish mariculture industry in Humboldt Bay has coexisted with various stakeholder groups and the Bay’s delicate ecology. Presently, the shellfish mariculture industry in Humboldt Bay is composed of six shellfish producing businesses ranging in operational size from small-scale to large-scale. Commercial shellfish production from Humboldt Bay yields over 70 percent of California’s mature, market-sized, Pacific oysters (Crassostrea gigas) and Kumamoto oysters (C. sikamea). Shellfish growers in the Bay also produce seed from Pacific oysters, Kumamoto oysters, and Manila clams (Tapes semidecussata).

As the mariculture industry in Humboldt Bay is poised to expand its footprint, very limited data about the industry have been made available for planners and decision makers. The purposes of this thesis were to: (1) Gather reliable socioeconomic data about

the state of the mariculture industry in Humboldt Bay. (2) Evaluate the industry’s

strengths...

Molluscan Shellfish Aquaculture in Federal Waters of the Exclusive Economic Zone (EEZ): Agencies, Industry, and Academia Working Together on Compliance and Permitting Requirements

Mon, 9 Dec 2024 00:00:00 +0000

Approximately 91% of the seafood products sold in the United States are imported, and roughly

half of those imports are produced by aquaculture.5 These seafood imports total 2.45 million

metric tons, 89,000-90,500 metric tons of which is comprised of molluscan shellfish (e.g. oysters,

mussels, clams, and scallops).6 These imports have contributed to a significant seafood trade

deficit, which ballooned to $14 billion in 2016.7 Increased domestic aquaculture production has

the potential to reduce this reliance on seafood imports, which could result in an estimated

additional 50,000 full-time and part-time jobs8 if United States “offshore” aquaculture production

is doubled.9 Furthermore, it has been suggested by some as a way to reduce the carbon footprint

associated with imported seafood.10

While the potential for increased domestic molluscan shellfish marine aquaculture production11

has been the subject of high-level...

DETERMINING POPULATION STRUCTURE, REPRODUCTIVE POTENTIAL, AND HABITAT ASSOCIATIONS OF PINTO ABALONE (HALIOTIS KAMTSCHATKANA) IN SOUTHERN CALIFORNIA

Mon, 9 Dec 2024 00:00:00 +0000

This study provides the first assessment of demographic and habitat information

for pinto abalone (Haliotis kamtschatkana) in San Diego, California, two decades after

the closure of all abalone fisheries in southern California. SCUBA surveys conducted

from June 2014 to December 2016 indicate that current low densities (0-0.03

individuals/m2) were far below critical thresholds identified for other abalone species

(0.15-0.30 abalone/m2) for successful spawning and recruitment. A broad range of sizes

were represented (13-146 mm), however, only 95 individuals were found. Some sites

showed significant aggregation of adult (> 50 mm) pinto abalone, 30% of adults had a

nearest-neighbor within a critical spawning distance of 2 m, and 65% had a neighbor

within 5 m, indicating that at least a small proportion of individuals may be capable of

reproducing successfully. Pinto abalone showed a significant preference for boulder

habitat...

California’s Experience with Dunes and Coastal Resilience: A Synthesis Report of the 2021 Coastal Dunes for Resilience Workshop.

Mon, 9 Dec 2024 00:00:00 +0000

This article provides a synthesis of the virtual Coastal Dunes for Resilience Workshop held on December 8th and 9th, 2021. In an effort to foster knowledge-sharing across these sites and disseminate information and lessons learned, the California Dune Science Network hosted the Workshop that featured recent dune research, information about nature-based dune and resilience projects, and collaborative learning opportunities at California's pilot project and natural dune sites. It also engaged diverse perspectives on coastal resource stewardship, public access, and culturally inclusive climate adaptation approaches and how these play a role in the success of coastal dune resilience efforts.

The Coastal Dunes for Resiliency Workshop provided an initial opportunity for ideas and strategies to be shared amongst the many practitioners working in the coastal resilience space. The workshop highlighted common challenges, needs, and four emerging themes for implementing coastal...

Sharing the Coast: Opportunities and strategies for accelerating coastal resilience in the San Diego-Baja California Region

Mon, 9 Dec 2024 00:00:00 +0000

The purpose of this document is to outline a strategic vision for enhancing coastal resilience in the San Diego-Baja California Region through binational collaboration. It draws from a needs assessment led by California Sea Grant and the Climate Science Alliance. This vision document identifies key opportunities and actionable strategies that integrate scientific research, traditional knowledge, and innovative practices to support resilient coastal communities and ecosystems. By fostering cross-border partnerships, expanding research capabilities, and engaging diverse stakeholders, this document aims to guide efforts towards a more resilient future for our shared coastline.

Building Climate Resilience of Urban Waters, Ecosystems, and Communities

Mon, 9 Dec 2024 00:00:00 +0000

particularly in urban ecosystems. The project site, Manzanita Canyon, is located in the heart of a

“disadvantaged” community in San Diego, California. In urban watersheds such as this, ecosystems

provide services disproportionate to their size, yet are also highly vulnerable to climate change hazards

because of the heavy reliance on services and the relatively degraded state. This two-year project

improved water quality and climate resilience of an urban ecosystem and an underserved community by

engaging 2,253 community members in stewardship activities; restoring 7.56 acres of native coastal

scrub ecosystem, including planting, maintaining and monitoring 1,536 natives; and removing 22 metric

tons (758 m3) of invasive plants and trash. Findings from this project formed the basis of the following

stewardship recommendations:

1. Community engagement was most effective when community-based leaders or organizations

were...

Living Shorelines & Resilience in Southern California: A Summary of a Series of Workshops held as part of The Resilient Coastlines Project of Greater San Diego

Wed, 12 Feb 2020 00:00:00 +0000

In 2016, a series of workshops were held to discuss living shorelines in Southern

California. The workshops specifically focused on the unique benefits, challenges and

opportunities for implementing living shorelines in the region, and the nexus between

nature-based solutions and ongoing local adaptation planning. Approximately 140

participants partook in these dialogues, and some of the key themes that emerged

include:

 Letting nature do the work for you

 Designing for the future

 Integrating nature into shoreline management projects

 Project goals distinguishing living shorelines

 Engineering and urban living shorelines

 Space constraints along urban coastlines

 Permitting pathways to support demonstration projects

 Living shorelines and phased sea level rise planning

 Designing with watersheds and sediment management in mind

 Exploring emerging commercial opportunities

...

Diets and Stable Isotope Signatures of Yellowtail Rockfish (Sebastes flavidus) in Central California

Fri, 20 Sep 2019 00:00:00 +0000

Studies of fish diets can improve the understanding of trophic distributions

and the predatory role of a species in an ecosystem. Identifying the spatial and

temporal variability in the diets of fishes can provide useful information for stock

assessments and management. Yellowtail Rockfish (Sebastes flavidus) are a

commercially and recreationally important fishery species, and abundant along

the central California coast, yet the most recent studies of diets occurred over 20

years ago in Oregon and Washington. To provide current information from

California, I examined the food habits of Yellowtail Rockfish collected near

Cordell Bank, the Farallon Islands, and Half Moon Bay in 2013 and 2014 using

gut content and stable isotope analyses. Yellowtail Rockfish analyzed in this

study were semi-pelagic predators, feeding primarily on tunicates, crustaceans,

and teleosts. Based on δ15N values, fish caught in 2013, on...

Local Seafood Availability in San Diego, California Seafood Markets

Thu, 3 Jan 2019 00:00:00 +0000

Like many developed coastal cities, San Diego, California has strong geographic and recreational ties to the adjacent ocean, but weak culinary ones. Less than 10% of the seafood consumed in the U.S., and San Diego in particular, is domestic. The popularity and abundance of farmers’ markets and other local markets in San Diego indicates an interest among producers and the public alike in cultivating local, diverse food systems, but this trend has been slower to catch on for seafood. The goal of this project was, therefore, to define and begin to understand the influences on the patterns of locally sourced, domestic seafood availability in San Diego. This study focused on seafood availability in seafood markets including researching market websites and contacting seafood counter managers to determine the general frequency (consistent, occasional, none) at which the markets sold seafood produced by San Diego fishermen or aquafarmers. Seafood market locations were mapped, and demographic...

Integrating collaborative data collection with management: A lobster fishery test case

Mon, 9 Jul 2018 00:00:00 +0000

Cost-effective programs for gathering essential fisheries information (EFI) are critically needed to

improve the data-poor state of fisheries in California and worldwide. The California Marine Life

Management Act (MLMA) recognizes this need and requires development of fishery management

plans (FMPs) that identify suitable protocols for collecting data, and use of the best available

scientific information to inform management. Furthermore, in the United States, several state

and federal laws require the engagement of fishermen and others in fisheries management. To

address these needs, we developed a collaborative at-sea sampling program (CASP) by:

• determining the key regulatory, administrative and operational features of established

collaborative fisheries data collection programs,

• developing a robust sampling design with associated protocols for the commercial

California spiny lobster fishery,

• designing,...

Angler exposure to domoic acid via consumption of contaminated fishes

Mon, 9 Jul 2018 00:00:00 +0000

Angler exposure to domoic acid via consumption of contaminated fishes

Collaborative fisheries research to build socioeconomic essential fishery information: A test case

Mon, 9 Jul 2018 00:00:00 +0000

Fisheries are integrated social-‐ecological systems, characterized by dynamic and complex interactions within and between the natural and human environments. California’s 1998 Marine Management Life Act (MLMA) recognizes the role of people in fisheries, and the MLMA Master Plan calls for the inclusion of socioeconomic as well as ecological “essential fishery information” in fishery management plans. However, critical gaps in such information for virtually all fisheries hinder managers’ ability to actively adapt and communities’ ability to plan for the future. This project begins to meet such information needs for the commercial fishery for California halibut, providing an example for other fisheries. We conducted a small collaborative fisheries research (CFR) project that engaged fishery participants, scientists and managers. Our goal was to produce sound social scientific understanding of the human dimensions of the fisheries system that is useful to the fishing, management,...

Figuring Out the Human Dimensions of Fisheries: Illuminating Models

Mon, 9 Jul 2018 00:00:00 +0000

Figuring Out the Human Dimensions of Fisheries: Illuminating Models

Managing Flow Regimes and Landscapes Together: Hydrospatial Analysis for Evaluating Spatiotemporal Floodplain Inundation Patterns with Restoration and Climate Change Implications

Fri, 6 Jul 2018 00:00:00 +0000

Riverine landscapes are shaped by dynamic and complex interactions between streamflow and floodplain landforms, and these physical processes drive productive and diverse freshwater ecosystems. However, human activities have fundamentally altered river-floodplain processes and degraded ecosystems. Flow regime variability has been homogenized and floodplains disconnected from rivers due to dams, diversions, levee building, and land use change. Reconciling competing demands to support ecosystems and resilience to future change is a core scientific and management challenge. This dissertation describes spatiotemporal dynamics of floodplain environments, introducing a method for flood regime classification and establishing a methodological approach for hydrospatial analysis to quantify and evaluate the response of floodplain inundation patterns and related physical habitat to restoration and flow regime change under climate change. It is motivated by the need to develop process-based...

Can the United States have its fish and eat it too?

Mon, 25 Jun 2018 00:00:00 +0000

As domestic affluence increases, nations advocate for conservation policies to protect domestic biodiversity that often curtail natural resource production activities such as fishing. If concomitant consumption patterns remain unchanged, environmentally-conscious nations with high consumption rates such as the U.S. may only be distancing themselves from the negative environmental impacts associated with consuming resources and commodities produced elsewhere. This unintended displacement of ecosystem impacts, or leakage, associated with conservation policies has not been studied extensively in marine fisheries. This paper examines this topic, drawing on case studies to illustrate the ways in which unilateral marine conservation actions can shift ecosystem impacts elsewhere, as has been documented in land use interventions. The authors argue that the U.S. should recognize these distant ecological consequences and move toward greater self-sufficiency to protect its seafood security...

Calcifying algae maintain settlement cues to larval abalone following algal exposure to extreme ocean acidification

Tue, 19 Jun 2018 00:00:00 +0000

Ocean acidification (OA) increasingly threatens marine systems, and is especially harmful to calcifying organisms. One important question is whether OA will alter species interactions. Crustose coralline algae (CCA) provide space and chemical cues for larval settlement. CCA have shown strongly negative responses to OA in previous studies, including disruption of settlement cues to corals. In California, CCA provide cues for seven species of harvested, threatened, and endangered abalone. We exposed four common CCA genera and a crustose calcifying red algae, Peyssonnelia (collectively CCRA) from California to three pCO₂ levels ranging from 419–2,013 µatm for four months. We then evaluated abalone (Haliotis rufescens) settlement under ambient conditions among the CCRA and non-algal controls that had been previously exposed to the pCO₂ treatments. Abalone settlement and metamorphosis increased from 11% in the absence of CCRA to 45–69% when...

Spatial and Temporal Examination of Bivalve Communities in Several Estuaries of Southern California and Northern Baja California, MX

Tue, 19 Jun 2018 00:00:00 +0000

Spatial and Temporal Examination of Bivalve Communities in Several Estuaries of Southern California and Northern Baja California, MX

BASELINE CHARACTERIZATION OF FISH COMMUNITIES ASSOCIATED WITHNEARSHORE ROCKY REEFS IN THE NORTHERN CALIFORNIA MARINEPROTECTED AREA STUDY REGIONS

Tue, 19 Jun 2018 00:00:00 +0000

BASELINE CHARACTERIZATION OF FISH COMMUNITIES ASSOCIATED WITHNEARSHORE ROCKY REEFS IN THE NORTHERN CALIFORNIA MARINEPROTECTED AREA STUDY REGIONS

The Resilience of Marine Ecosystems to Climatic Disturbances

Tue, 12 Jun 2018 00:00:00 +0000

The intensity and frequency of climate-driven disturbances are increasing in coastal marine ecosystems. Understanding the factors that enhance or inhibit ecosystem resilience to climatic disturbance is essential. We surveyed 97 experts in six major coastal biogenic ecosystem types to identify “bright spots” of resilience in the face of climate change. We also evaluated literature that was recommended by the experts that addresses the responses of habitat-forming species to climatic disturbance. Resilience was commonly reported in the expert surveys (80% of experts). Resilience was observed in all ecosystem types and at multiple locations worldwide. The experts and literature cited remaining biogenic habitat, recruitment/connectivity, physical setting, and management of local-scale stressors as most important for resilience. These findings suggest that coastal ecosystems may still hold great potential to persist in the face of climate change and that local- to regional-scale management...

Effects of Flow-Related Variables on Oversummer Survival of Juvenile Coho Salmon in Intermittent Streams

Tue, 12 Jun 2018 00:00:00 +0000

While many studies have established the importance of streamflow as a driver of fish population dynamics, few have examined relationships between survival of juvenile salmonids and flow-related variables in intermittent streams. With predictions for higher frequency of drought conditions due to climate change, and the associated increasing human demand for water during the dry season, understanding fish–flow relationships is becoming increasingly important for the protection of sensitive aquatic species. To examine the effects of low streamflow on juvenile salmonids rearing in small intermittent streams, we estimated survival and collected environmental data in four coastal California watersheds from 2011 to 2013. We used an individual-based mark-recapture modeling approach to evaluate the influence of flow-related variables on oversummer survival of PIT-tagged juvenile Coho Salmon stocked into eight stream reaches. Survival was positively associated with streamflow magnitude,...

Managing Small-Scale Commercial Fisheries for Adaptive Capacity: Insights from Dynamic Social-Ecological Drivers of Change in Monterey Bay

Tue, 12 Jun 2018 00:00:00 +0000

Globally, small-scale fisheries are influenced by dynamic climate, governance, and market drivers, which present social and ecological challenges and opportunities. It is difficult to manage fisheries adaptively for fluctuating drivers, except to allow participants to shift effort among multiple fisheries. Adapting to changing conditions allows small-scale fishery participants to survive economic and environmental disturbances and benefit from optimal conditions. This study explores the relative influence of large-scale drivers on shifts in effort and outcomes among three closely linked fisheries in Monterey Bay since the Magnuson-Stevens Fisheries Conservation and Management Act of 1976. In this region, Pacific sardine (Sardinops sagax), northern anchovy (Engraulis mordax), and market squid (Loligo opalescens) fisheries comprise a tightly linked system where shifting focus among fisheries is a key element to adaptive capacity and reduced social and...

Seasonal fish and invertebrate communities in three northern California estuaries

Tue, 23 Jan 2018 00:00:00 +0000

The majority of Northern California estuaries are small, flooded, river valleys that are largely unstudied due to their small sizes and remote locations. Yet these estuaries serve as important nursery areas for many marine fish species including rockfish, flatfish, smelt, and herring, and they are vital to anadromous species such as Chinook Salmon (Oncorhynchus tshawytscha) and Steelhead (O. mykiss). I sampled the summer and winter fish and invertebrate communities of the Big, Mad, and Ten Mile river estuaries. Fish were sampled via beach seine or fyke net and invertebrates were sampled via benthic cores, June 2014-June 2016. This research is part of a larger suite of studies establishing baseline conditions in Northern California Marine Protected Areas (MPAs). Big and Ten Mile river estuaries in Mendocino County were designated as MPAs in 2012. The Mad River Estuary in Humboldt County was selected as a non-MPA site to investigate its potential as a reference estuary. In the Mad...

Juvenile survival and adult return as a function of freshwater rearing life history for Coho Salmon in the Klamath River Basin

Tue, 23 Jan 2018 00:00:00 +0000

The Scott and Shasta rivers, Klamath River tributaries, experience spatial disparity in habitat quality in spring and summer as a result of historical and current landuse.

Juvenile Coho Salmon (Oncorhynchus kisutch) born in the upper tributary reaches often rear in natal streams before migrating to sea. However, those born in the lower reaches often encounter unsuitable habitat and emigrate during their first spring to seek non-natal rearing habitats. It is assumed that these early outmigrants are population losses. This study evaluated first-summer survival, and contribution to the adult population, of non-natal rearing juveniles in the Klamath River Basin. In the spring of 2014 and 2015 juveniles were tagged using Passive Integrated Transponder (PIT) tags as they were leaving the lower Scott and Shasta Rivers. Movement and survival was subsequently tracked using recapture and detection efforts in potential mainstem summer rearing locations. Strontium microchemistry...

The response of a predatory fish, Opiodon elongatus, to a marine protected area: variation in diet, catch rates, and size composition

Tue, 23 Jan 2018 00:00:00 +0000

Marine Protected Areas (MPAs) are a management tool used to protect and sustain many ecologically and economically important fish species from overexploitation by recreational and commercial fishing. Lingcod (Ophiodon elongatus) and some of its prey species, such as rockfish (Sebastes spp.), are species that are protected from fishing in some California MPAs. Lingcod is an apex predator that consumes a variety of fish and invertebrate species. In this study, I sought to assess the effect of an MPA on the abundance, size and diet of Lingcod. I hypothesized that Lingcod in a no-take MPA would be more abundant and larger than Lingcod in an adjacent reference site (REF) that was open to fishing. Furthermore, I hypothesized that diet would differ between Lingcod in caught the MPA and Lingcod in the REF. I collected Lingcod from the Point Buchon State Marine Reserve (MPA) and an adjacent REF site that was open to fishing. I measured, weighed, sexed, and collected stomach contents from...

Economic effects of Pacific halibut closures on businesses on the North Coast and the age, growth, and reproductive status of Pacific halibut in Northern California and Central Oregon

Tue, 23 Jan 2018 00:00:00 +0000

Traditionally, the recreational fishery for Pacific halibut has been open in California from 1 May through 31 October. In 2014, however, the Pacific halibut fishery was closed in California during the month of August for the first time in history in an effort to reduce harvest and bring total catch closer to what is allocated to our region by the Pacific Fisheries Management Council (PFMC) Catch Sharing Plan. To determine the effects that the closure had on businesses along the North Coast, I conducted an economic impact survey in 2014. The results of the survey showed that fishing-related businesses lost between zero percent and eight percent of their revenue in 2014, as a result of the closure; lodging and traveler service companies lost between 0.3 percent and one percent of their revenue in the same year. None of the businesses changed the number of employees as a result of the closure. We estimated a decrease in revenue for businesses on the North Coast to be between $189,750...

Expectations and adaptation to environmental risks

Tue, 23 Jan 2018 00:00:00 +0000

Expectations and adaptation to environmental risks

Adaptive Management of Marine Protected Areas: Predicting Responses to MPA Implementation for Comparison to Monitoring Data

Fri, 15 Dec 2017 00:00:00 +0000

Adaptive Management of Marine Protected Areas: Predicting Responses to MPA Implementation for Comparison to Monitoring Data

Studying gravel bars in rivers to identify what features facilitate groundwater exchanges that create good Chinook salmon spawning habitat

Mon, 8 May 2017 00:00:00 +0000

Studying gravel bars in rivers to identify what features facilitate groundwater exchanges that create good Chinook salmon spawning habitat

Optimizing salt marsh harvest mouse conservation through an investigation of demography, habitat use andmulti-species management

Mon, 8 May 2017 00:00:00 +0000

Optimizing salt marsh harvest mouse conservation through an investigation of demography, habitat use andmulti-species management

Examining the effects of perennial pepper weed on tidalmarsh ecosystems and identifying strategies to stop thenoxious weed’s spread

Mon, 8 May 2017 00:00:00 +0000

Examining the effects of perennial pepper weed on tidalmarsh ecosystems and identifying strategies to stop thenoxious weed’s spread

Determining thermal tolerances of longfin smelt and inland silverside and develop biomarkers of thermal stress using new genomics technology

Mon, 8 May 2017 00:00:00 +0000

Determining thermal tolerances of longfin smelt and inland silverside and develop biomarkers of thermal stress using new genomics technology

The Effects of 4-nonylphenol on the Immune Response of the Pacific oyster, Crassostrea gigas, Following Bacterial Infection (Vibrio campbellii)

Thu, 1 Sep 2016 00:00:00 +0000

The Effects of 4-nonylphenol on the Immune Response of the Pacific oyster, Crassostrea gigas, Following Bacterial Infection (Vibrio campbellii)

CREATION AND UTILIZATION OF NOVEL GENETIC METHODS FOR STUDYING AND IMPROVING MANAGEMENT OF CHINOOK SALMON POPULATIONS

Tue, 28 Oct 2014 00:00:00 +0000

CREATION AND UTILIZATION OF NOVEL GENETIC METHODS FOR STUDYING AND IMPROVING MANAGEMENT OF CHINOOK SALMON POPULATIONS

Understanding Food Webs in Shallow Nearshore Waters of the Delta

Fri, 24 Oct 2014 00:00:00 +0000

Understanding Food Webs in Shallow Nearshore Waters of the Delta

Salinity Tolerances and Biomarkers of Salt Stress in Longfin and Delta Smelt

Fri, 24 Oct 2014 00:00:00 +0000

Salinity Tolerances and Biomarkers of Salt Stress in Longfin and Delta Smelt

Controls on the Net Carbon Emissions from Restored Wetland Ecosystems

Fri, 24 Oct 2014 00:00:00 +0000

Controls on the Net Carbon Emissions from Restored Wetland Ecosystems

Modeling Wetland Plant Cover to Assess Ecosystems and Bird Habitats

Fri, 24 Oct 2014 00:00:00 +0000

Modeling Wetland Plant Cover to Assess Ecosystems and Bird Habitats

Unraveling Sources of Food Web Support in the Sacramento-San Joaquin Delta’s Marsh Ecosystem

Fri, 24 Oct 2014 00:00:00 +0000

Unraveling Sources of Food Web Support in the Sacramento-San Joaquin Delta’s Marsh Ecosystem

Noroviruses in coastal waters: Implications for seafood cultivation and human health

Tue, 2 Sep 2014 00:00:00 +0000

Noroviruses in coastal waters: Implications for seafood cultivation and human health

Seasonal variation of diatoms and dinoflagellates in Monterey Bay, CA determined by Chemtax alanysis of HPLC pigment data

Mon, 9 Jun 2014 00:00:00 +0000

Phytoplankton samples were collected off the Monterey Municipal Wharf II at a single location (36º 36’ N and 121º 53’ W) weekly from June 2003 to March 2010. The contribution of five algal groups to total chlorophyll a (chl a) was derived using CHEMTAX from biomarker pigment measurements made via HPLC analysis. The purpose of this study was to specifically define the relative abundances of diatoms and dinoflagellates on a seasonal and interannual basis. Spearman’s rho (ρ) correlation coefficients were calculated to determine the strength of the relationship between the diatoms and dinoflagellates and two environmental variables; sea surface temperature (SST) and upwelling indices (UI). During the summer of 2004 and until the end of 2006, previous studies had suggested that the typical diatom-dominated bay shifted to a dinoflagellate-dominated system resulting from global warming effects on mixed layer stability. The high-resolution (weekly), long-term (2003-2010) sampling regime...

The population dynamics of mitten crab larvae in the San Francisco Bay

Mon, 9 Jun 2014 00:00:00 +0000

The Chinese mitten crab, Eriocheir sinensis, has a history of invasions in numerous countries. In 1992, the Chinese mitten crab was introduced to the San Francisco Bay/Delta system. Since its invasion in the San Francisco Bay, it has become an aquatic nuisance species. Little is known about the population dynamics of the megalopa stage of the Chinese mitten crab in the San Francisco Bay estuary, particularly the megalopa stage. Light traps are often used to sample marine larvae and can provide measures for relative abundance of larvae between sampling locations. As part of an ongoing study to monitor mitten crab larvae in the San Francisco Bay, light trap and plankton tow samples were analyzed formitten crab megalopae and zoeae. In order to implement low cost sampling devices for mitten crab megalopae such as light traps, it is necessary to be able to identify their larvae in collected samples. Thus, the main objective of this work was to develop a means to distinguish mitten...

Floodplain restoration planning for a changing climate: Coupling flow dynamics with ecosystem benefits

Mon, 2 Jun 2014 00:00:00 +0000

This dissertation addresses the role that dynamic flow characteristics play in shaping the potential for significant ecosystem benefits from floodplain restoration. Mediterranean-climate river systems present challenges for restoring healthy floodplains because of the inter and intra-annual variability in stream flow, which has been dramatically reduced in an effort to control flooding and to provide a more consistent year-round water supply for human use. Habitat restoration efforts require that this reduced stream flow be altered in order to recover more naturally dynamic flow patterns and reconnect floodplains. This thesis defines and takes advantage of an eco-hydrology modeling framework to reveal how the ecological returns of different hydrologic alterations or restoration scenarios—including changes to the physical landscape and flow dynamics—influence habitat connectivity for freshwater biota. A method for quantifying benefits of expanding floodplain connectivity can...

Interannual-to-Decadal Changes in Phytoplankton Phenology, Fish Spawning Habitat,and Larval Fish Phenology

Thu, 22 May 2014 00:00:00 +0000

Phenology is the study of seasonal, biological events and how they are influenced by climate. Climate change has prompted an earlier arrival of spring in numerous ecosystems. It is uncertain whether such changes are occurring in coastal upwelling ecosystems, because these regions are subject to decadal climate oscillations and regional climate models predict later seasonal upwelling. To answer this question, chapter 1 investigated decadal changes in the phenology of 43 larval fish species in southern California. The first principal component of this dataset showed a progression towards the earlier appearance of larvae, although 18% of phenological events exhibited seasonal delays. These changes were best explained by a secular trend towards earlier warming of surface waters. Species with earlier phenology were characterized by an offshore, epipelagic distribution, while fishes with delayed phenology were more likely reside in coastal, demersal habitats. Chapter 2 focused on improving...

Controlling Marine Invasive Species: The case of the Indo-Pacific Lionfish Invasion in the Southeast U.S. and Caribbean

Wed, 21 May 2014 00:00:00 +0000

Our hypothesis is that modeling features common to marine biological invasions, like the ability of the invader to disperse over long distances, will call for invasive Indo-Pacific lionfish (Pterois volitans and P. miles) control policies that diverge from those that are efficient based on models geared towards terrestrial and freshwater species, and that these differences will be economically significant.

Controlling Marine Invasive Species: The case of the Indo-Pacific Lionfish Invasion in the Southeast U.S. and Caribbean

Fri, 16 May 2014 00:00:00 +0000

Exploting marine actinomycete diversity for natural product discovery

Fri, 16 May 2014 00:00:00 +0000

The project hypotheses have not changed. We continue to address questions related to the diversity and distributions of MAR4 actinomycetes in marine sediments, the relationships between who these bacteria are (phylogeny), the types of secondary metabolites they produce, and the mechanistic biochemistry responsible for their biosynthesis.

Human dimensions perspectives on the impacts of coastal zone marine renewable energy

Fri, 16 May 2014 00:00:00 +0000

Climate change and soaring energy costs have fueled attention to renewable energy. In coastal areas, the potential to harness the clean power of offshore wind, wave, and tide is irresistible. Our extensive coasts and oceans offer what appears at first glance to be virgin territory for development of energy producing facilities. A closer look,however, reveals that these areas are teeming with productive activity, activity that cannot be ignored in planning and implementing marine renewable energy (MRE) development and production.

Assessing selected Pacific Oyster stocks for disease resistance in Tomalas Bay, California

Thu, 1 May 2014 00:00:00 +0000

Assessing selected Pacific Oyster stocks for disease resistance in Tomalas Bay, California

MPA-Based Collaborative Techniques to Improve Management of Nearshore Fisheries

Thu, 1 May 2014 00:00:00 +0000

MPA-Based Collaborative Techniques to Improve Management of Nearshore Fisheries

The effects of freshwater flows on the native Olympia oyster in San Francisco Estuary

Mon, 16 Dec 2013 00:00:00 +0000

After heavy winter storms, salinity levels in the San Francisco Estuary can drop precipitously, stressing and sometimes killing organisms such as the native Olympia oyster (Ostrea conchaphila ) and invasive Mediterranean mussel (Mytilus galloprovincialis ).

Phytoplankton and bacteria nutrient use: impacts of nutrient loading on the base of the food web

Mon, 16 Dec 2013 00:00:00 +0000

Treated municipal wastewater contains a form of nitroge known as ammonium. When discharged into waterways, this ammonium may alter phytoplankton (algal) communities and potentially degrade available food resources for zooplankton and other organisms.

Saving San Francisco Bay-Delta native fishes: hatchery management and reinintroduction strategies

Mon, 16 Dec 2013 00:00:00 +0000

Several native fish species in the San Francisco Bay-Delta and Central Valley have experienced dramatic population declines and could realistically go extinct in the wild.

The effects of bifenthrin pesticide on the reproductive health of steelhead under hypersaline conditions.

Mon, 16 Dec 2013 00:00:00 +0000

Salmon and steelhead in the San Francisco Bay-Delta face many challenges, including exposure to pesticides in runoff and municipal wastewater discharges.