Central California Coast Research Articles

Central Coast Regional Equity Initiative: Co-Creating and Actionizing a New Community-Led Equity Framework

We present a community-led equity framework as a foundation for promoting equity on the Central Coast of California. We discuss the key elements of a participatory, community-led evaluation and planning approach for the Central Coast Regional Equity Initiative, which aims to advocate for social, health, environmental, and economic equity through region-wide cross-sector collaboration, community and research-informed action, and an indigenized and decolonized approach. Through a systematic mixed-methods evaluation and planning approach, including Community Consultations and Strategic Action Planning, we found that our community’s lived experience contributes to a deeper understanding of inequities, and that engagement in cross-sector collaboration empowers our community to bridge data with action organizing. The findings demonstrate that engagement in community-led evaluation and planning contributes to a greater readiness for cross-sector collaborative action and a sense of community ownership of solutions to equity issues, and sets the stage for deeper-rooted, long-term success built on genuine reciprocity and trust. We present our community-led equity framework inviting others to adopt systematic community knowledge-base-building that values community wisdom, identifies power imbalance, promotes trust-building through healthy discomfort, and encourages reflective action.

A marine protected area network does not confer community structure resilience to a marine heatwave across coastal ecosystems.

Marine protected areas (MPAs) have gained attention as a conservation tool for enhancing ecosystem resilience to climate change. However, empirical evidence explicitly linking MPAs to enhanced ecological resilience is limited and mixed. To better understand whether MPAs can buffer climate impacts, we tested the resistance and recovery of marine communities to the 2014-2016 Northeast Pacific heatwave in the largest scientifically designed MPA network in the world off the coast of California, United States. The network consists of 124 MPAs (48 no-take state marine reserves, and 76 partial-take or special regulation conservation areas) implemented at different times, with full implementation completed in 2012. We compared fish, benthic invertebrate, and macroalgal community structure inside and outside of 13 no-take MPAs across rocky intertidal, kelp forest, shallow reef, and deep reef nearshore habitats in California's Central Coast region from 2007 to 2020. We also explored whether MPA features, including age, size, depth, proportion rock, historic fishing pressure, habitat diversity and richness, connectivity, and fish biomass response ratios (proxy for ecological performance), conferred climate resilience for kelp forest and rocky intertidal habitats spanning 28 MPAs across the full network. Ecological communities dramatically shifted due to the marine heatwave across all four nearshore habitats, and MPAs did not facilitate habitat-wide resistance or recovery. Only in protected rocky intertidal habitats did community structure significantly resist marine heatwave impacts. Community shifts were associated with a pronounced decline in the relative proportion of cold water species and an increase in warm water species. MPA features did not explain resistance or recovery to the marine heatwave. Collectively, our findings suggest that MPAs have limited ability to mitigate the impacts of marine heatwaves on community structure. Given that mechanisms of resilience to climate perturbations are complex, there is a clear need to expand assessments of ecosystem-wide consequences resulting from acute climate-driven perturbations, and the potential role of regulatory protection in mitigating community structure changes.

Documentation of microplastics in the gastrointestinal tracts of terrestrial raptors in central California, USA

Microplastics are persistent environmental contaminants that to date have been studied primarily in aquatic systems, but few studies have examined their prevalence or impact in terrestrial trophic networks. A recent study documented microplastics in the gastrointestinal (GI) tracts of terrestrial raptors in central Florida. We used protocols based on that study to develop a baseline dataset of microplastics in the GI tracts of terrestrial raptors on the central coast of California. In 2021, Pacific Wildlife Care, a wildlife rehabilitation center in Morro Bay, CA, provided 16 raptor carcasses: three red-tailed hawks (Buteo jamaicensis), four red-shouldered hawks (Buteo lineatus), two great horned owls (Bubo virginianus), and seven barn owls (Tyto alba). We found microplastics in the GI tracts of all 16 birds, with a mean (± SE) of 12.25 (± 1.89) microplastic particles per bird. Of the 196 microplastic particles we observed, microfibers were the most abundant (58%), followed by microbeads (34%), and microfragments (8%). However, microbeads were the most prevalent, found in all 16 birds, followed by microfibers (15 birds), and microfragments (6 birds). The chemical composition and source of these contaminants remains unclear, along with the physiological and ecological implications to raptor populations and their ecosystems, and the extent to which microplastics occur in other terrestrial species and regions in California.

Temperature and Cap Management Effects on the Chemical, Phenolic, and Chromatic Composition of Pinot noir Wines from the Central Coast of California

Temperature and Cap Management Effects on the Chemical, Phenolic, and Chromatic Composition of Pinot noir Wines from the Central Coast of California

Hosgri Fault Transpressional Slip Rates Reproduce Observed Central California Coast Uplift Rates

Abstract Coastal uplift is a common feature of Pacific Rim tectonic deformation. The 1989 Mw 7.0 Loma Prieta earthquake illustrated that reverse-oblique slip on a transpressive segment of the predominantly horizontal slip San Andreas transform fault produces coastal uplift. In west-central California the 400 km long San Gregorio-Hosgri fault coastal fault system of near-vertical to steeply northeast-dipping, reverse-oblique, dextral strike-slip faults also contribute to coastal uplift. Published southern Hosgri fault dextral slip rates are ∼4× reverse rates. Viscoelastic deformation modeling using published transpressional slip rates along the southern Hosgri fault reproduces observed emergent marine terrace uplift rates, offshore Hosgri fault deformation morphology, and crustal structure from San Luis Obispo Bay to Estero Bay. Our coastal uplift rate modeling is constrained by a unique combination of measurements: (1) offshore reverse- and strike-slip Hosgri fault zone (HFZ) slip rates, and (2) ≤125 ka onshore emergent terrace uplift rates adjacent to the HFZ. The previously proposed conceptual rigid block models of the southern central California coast (CCC) invoke local onshore thrust or reverse faults to explain coastal uplift. Observed transpressional offshore Hosgri fault deformation rates alone rigorously reproduce observed coastal uplift rates and crustal structure along the southern CCC.

Implementing youth participatory action research at a continuation high school.

To describe the process of implementing a Youth Participatory Action Research (YPAR) project at a continuation high school (CHS) and share the results of a youth-designed research project that explores barriers to high school completion. YPAR was implemented across three cohorts at a CHS in the central coast of California from 2019 to 2022. Student survey respondents were enrolled CHS students between March and April 2021. A modified YPAR curriculum integrating research methodology and social justice topics was used to guide student-led research that resulted in a cross-sectional survey. Field notes maintained by the first author documented the process of implementing YPAR including the curriculum, conversations, and research decisions and procedures. A student-designed survey disseminated to all enrolled students resulted in 76 (66%) participant responses. The survey included 18 close-ended questions and three narrative responses. This study details how YPAR methodologies can be translated to a high school credit recovery program. For example, student cohorts were needed to maintain continuity over time. A student-designed survey revealed that 72% of student respondents reported taking care of family members and illuminated high rates of depression symptoms. This study offers a detailed description of how we implemented YPAR at a credit recovery program and provides student-driven perspectives on educational reform and evaluation. This project addresses the implementation and challenges of using YPAR to engage youth in transformational resistance to rapidly study and improve CHS' policy and practice.

Moment tensor event identification for collapses

SUMMARY We introduce a seismic identification method for collapse events using moment tensors (MTs). We start by computing full (six-element) MT solutions for 43 identified collapse events from around the world, and statistically characterizing the population on the MT hypersphere. We then test a large data set of over 1000 full MTs for the western U.S. against the distribution of collapses using a MT-based identification method similarly as used for testing explosions. Known collapses and explosions are readily identified, along with other anomalous events in the Geysers and central California coast. Misidentification rates are determined for various screening angles with optimal misidentification rates between earthquakes and collapses on the order of 3 per cent. The method is demonstrated to be very effective at identifying non-earthquake sources with a 97–98 per cent accuracy. It is likely to be transportable to other regions, and can be used for event identification anywhere full MT solutions are routinely calculated.

The Impact of Fermentation Temperature and Cap Management on Selected Volatile Compounds and Temporal Sensory Characteristics of Grenache Wines from the Central Coast of California.

Grenache wines from the Central Coast of California were subjected to different alcoholic fermentation temperature regimes (Cold, Cold/Hot, Hot) and cap management protocols, namely, punch down (PD), or no punch down (No PD), to determine the effect of these practices on the color, aroma, and the retronasal and mouthfeel sensory characteristics of the resulting wines. Descriptive analysis (n = 8, line scale rating 0-15) results indicated that the combination of a hot fermentation temperature and no punch downs led to a significantly higher intensity in perceived color saturation (7.89) and purple hue (8.62). A two-way analysis of variance (ANOVA) showed that cap management was significantly more impactful on the perception of orthonasal aromas than fermentation temperature. The reduction aroma was significantly higher in No PD wines (5.02) compared to PD wines (3.50), while rose and hot aromas had significantly higher intensity perception for PD wines (5.18, 6.80) than for No PD wines (6.80, 6.14). Conversely, analysis of selected volatile compounds indicated that fermentation temperature was more impactful than cap management regime. Cold/Hot wines had higher concentrations of important esters such as ethyl hexanoate (650 µg/L) and isoamyl acetate (992 µg/L). Cold wines had a higher concentration of β-damascenone (0.719 µg/L). TCATA evaluation (n = 8) indicated that Cold/Hot PD wines had a significantly higher citation proportion of fruit flavor (1.0) and velvet astringency perception (0.80) without significant reduction flavors. Finally, the present study represents a contribution with the main volatile compounds (e.g., β-damascenone and esters in the Cold and Cold/Hot fermented wines, respectively; hexanol in PD wines, which may be potentially responsible for a hot mouthfeel), and sensory characteristics (red fruit, tropical fruit, white pepper, and rose) of Grenache wines grown in the Mediterranean climate of the Central Coast of California.

Relative Susceptibility of Brassicas to Cabbage Maggot (Diptera: Anthomyiidae) Infestation.

Cabbage maggot, Delia radicum (L.) (Diptera: Anthomyiidae) is a serious pest of Brassica such as broccoli (Brassica oleracea var. italica Plenck) and cauliflower (B. oleracea L. var. botrytis) in California's Central Coast. Since there are limited non-chemical options available for growers to manage D. radicum, there is an urgent need to develop alternative tactics. The objective of this study was to determine the effects of side-by-side plantings of turnip (Brassica rapa var. rapa L.), lettuce (Lactuca sativa L.), cauliflower, and cabbage (B. oleracea L. var. capitata) with broccoli on D. radicum infestation. In 2013 and 2014, the experiments were conducted in Salinas, California. Significantly greater numbers of eggs and larval feeding damage were found on turnip compared with broccoli. Lettuce (Asteraceae), a non-Brassica crop, was compared with broccoli; however, lettuce did not reduce oviposition or larval feeding damage on broccoli. The larval feeding damage on cauliflower was significantly lower than on broccoli when planted side-by-side. The effects on cabbage were not significantly different from broccoli in terms of oviposition and larval feeding damage. This new information generated from the Central Coast of California will be further utilized to develop a trap crop to effectively tackle the D. radicum problem in Brassica fields.

Short-term effects of increasing compost application rates on soil C and greenhouse gas (N2O and CO2) emissions in a California central coast vineyard

Compost application is commonly considered by winegrape producers to improve soil health while sequestering carbon (C) and mitigating climate change. However, inputs of available C and nitrogen (N) as nutrients can induce emissions of greenhouse gases (GHG) such as carbon dioxide (CO2) and nitrous oxide (N2O). A 2-year field experiment in a Mediterranean vineyard on the California Central Coast was conducted to investigate the short-term effects of compost application at four different rates on soil C dynamics and greenhouse gas emissions. Two years of greenhouse gas sampling were performed using static chambers at vineyard management events in two functional locations (tractor row and under the vines). Soil samples were collected annually in spring at the same locations at 0–15, 15–30 and 30–60 cm depth, and during greenhouse gas sampling at 0–15 cm. The increasing compost application rate did not increase soil C stock, cumulative greenhouse gas emissions and global warming potential. The increase in active soil C observed to the depth of 60 cm suggests that increasing the compost application rate up to the rate of 13.5 Mg ha-1 year-1 can facilitate the early stages of C stabilization and sequestration. Compost application did not have a significant effect on grape yield or cover crop growth during the study. Our results provided important information on the potential environmental tradeoffs as greenhouse gas emissions from compost applications, which should be taken into account when considering the vineyard C budget.

California coastal access damage from early winter 2022-2023 storms: A photo essay

Atmospheric rivers, “bomb cyclones,” storm waves and high tides wreaked havoc along the central California coast from San Francisco to Monterey. From 26 December 2022 to 11 January 2023, more than 10 inches of rain fell in central California (Landers 2023). During this same time period, higher high tides were 6-ft or greater for 10 of these days and 35-ft high waves were noted. Beaches, beach accesses, and coastal trails were on the front lines for storm defenses and damage. In addition to the extensive new coverage, the National Oceanic and Atmospheric Administration’s National Geodetic Survey (NOAA/NGS) collected continuous post-storm(s) airborne photography along the west coast that will be invaluable in analyzing future long-term shoreline changes (NOAA/NGS 2023). The following photos, taken soon after the storms, show some of the coastal damage near and in Monterey Bay.

Indigenous stewardship of coastal resources in native California

Indigenous people have profoundly influenced terrestrial and marine ecosystems by modifying coastal habitats to increase the productivity of target species and altering local biotas through their harvesting practices. In some cases, these actions led to local resource depression, while in other instances, Indigenous people engaged with terrestrial and marine resources in sustainable ways, increasing the resilience of ecosystems. In this paper, we interrogate human-environmental relationships that span the last ∼7,000 years of Indigenous engagement with coastal resources on the central California coast. Through a historical ecological framework, we assess how Indigenous peoples interacted with terrestrial and marine ecosystems differently across space and through time. In the Middle Holocene, the region’s archaeology is typified by mobile populations using diverse terrestrial and marine resources. By the Late Holocene, Indigenous peoples intensified their economies towards a limited number of marine and terrestrial species. During this time, Indigenous people initiated sustained fire management practices that created habitat mosaics still reflected in the contemporary landscape. In the Late Holocene, people also developed resource harvesting strategies for California mussels and forage fishes geared towards long-term productivity.

Assessing the influence of rocket launch and landing noise on threatened and endangered species at Vandenberg Space Force Base

Understanding how species of concern respond to anthropogenic activities is becoming increasingly important. While the ways in which anthropogenic activities affect species are many, our understanding the effects of anthropogenic noise on species is still developing. Vandenberg Space Force Base (VSFB) along the California Central Coast presents a unique opportunity to study the effects of anthropogenic noise on species of concern as (1) the rate of rocket launches/landings is predicted to significantly increase in the coming years compared to the last three decades and (2) there are multiple threatened and endangered species at VSFB that may be impacted by the increased launch cadence. Our interdisciplinary research team composed of wildlife biologists and acousticians will be studying the short and long-term behaviors of threatened and endangered shorebirds that nest relatively close to active VSFB launch complexes. Using previously collected and current bird counts and acoustic data from VSFB, models will be created that describe behavioral changes in species of concern. We will discuss the scope and overview of this project.

Spatiotemporal variability of dissolved oxygen in response to morphological state in a central California coast bar-built estuary

Bar-built estuaries (BBEs) or intermittently closed/open lagoons (ICOLs) are common to coastal regions experiencing episodic river flows and seasonal precipitation changes along the US West Coast. Unique to Mediterranean climates, BBEs have a hydrologic mixing regime and variation in water chemistry characteristics resulting from seasonal breaches and closures of their mouth and watershed inputs. This study observes spatiotemporal variability in dissolved oxygen (DO) in a small bar-built estuary in Carmel, CA during variable morphological states. For this study, field measurements were collected using dissolved oxygen loggers during a seasonal transition from fully open to fully closed states to determine the spatiotemporal variability of dissolved oxygen within the three main branches of Carmel River Lagoon. The data collected spanned a 6-month (February to August 2020) period, covering several transitions from fully open to intermittently closed to fully closed mouth state. This study did not document any periods within the lagoon when dissolved oxygen concentrations were uniformly below water quality objective levels (5 mg/L) suggesting that during the entire period of this investigation, portions of the lagoon supported high oxygen conditions while also supporting a variety of other water chemistry characteristic zones, unique to BBEs. The dissolved oxygen fluctuations were closely tied to the temporal effects of environmental forcing (river discharge) on the seasonal transition of river mouth morphological state from fully open to fully closed. The main conclusion is that during open mouth states, relative DO variability in the bottom of the main channel is low and more similar to surface waters, indicating mixing, and during closed mouth states vertical location in the water column matters more. Furthermore, variability between sites suggests single point observations of DO cannot accurately represent the distribution of DO within a BBE.

Remote sensing of hedgerows, windbreaks, and winter cover crops in California's Central Coast reveals low adoption but hotspots of use

Non-crop vegetation, such as hedgerows and cover crops, are important on-farm diversification practices that support biodiversity and ecosystem services; however, information about their rates and patterns of adoption are scarce. We used satellite and aerial imagery coupled with machine learning classification to map the use of hedgerows/windbreaks and winter cover crops in California's Central Coast, a globally important agricultural area of intensive fresh produce production. We expected that adoption of both practices would be relatively low and unevenly distributed across the landscape, with higher levels of adoption found in marginal farmland and in less intensively cultivated areas where the pressure to remove non-crop vegetation may be lower. Our remote sensing classification revealed that only ~6% of farmland had winter cover crops in 2021 and 0.26% of farmland had hedgerows or windbreaks in 2018. Thirty-seven percent of ranch parcels had cover crops on at least 5% of the ranch while 22% of ranches had at least one hedgerow/windbreak. Nearly 16% of farmland had other annual winter crops, some of which could provide services similar to cover crops; however, 60% of farmland had bare soil over the winter study period, with the remainder of farmland classified as perennial crops or strawberries. Hotspot analysis showed significant areas of adoption of both practices in the hillier regions of all counties. Finally, qualitative interviews revealed that adoption patterns were likely driven by interrelated effects of topography, land values, and farming models, with organic, diversified farms implementing these practices in less ideal, lower-value farmland. This study demonstrates how remote sensing coupled with qualitative research can be used to map and interpret patterns of important diversification practices, with implications for tracking policy interventions and targeting resources to assist farmers motivated to expand adoption.

Predicting cereal cover crop biomass using shoot length in California vegetable systems

AbstractTo better understand cover crop benefits and receive nitrogen scavenging credits for cover cropping, farmers need simple and robust methods of predicting cover crop biomass production. A new regulation focused on improving nitrogen management on over 200,000 ha of irrigated land in the central coast of California motivated us to evaluate if the shoot length of rye (Secale cereale L., ‘Merced’) and triticale (× Triticosecale Wittmack, ‘Pacheco’) could predict shoot biomass. Field samples for rye (n = 162) and triticale (n = 126) were collected at various developmental growth stages from organic and conventional vegetable farms and planting date trials, across multiple soil types, planting times, row spacings, and plant densities. Main shoot length was well‐correlated with oven‐dry shoot biomass for rye (r2 = 0.87) and triticale (r2 = 0.88). This provides farms in California and beyond with a simple, robust method to estimate cover crop shoot biomass.

Exploring plant and soil microbial communities as indicators of soil organic carbon in a California rangeland

Soil organic carbon (SOC) is increasingly a focus of land management and policy initiatives, due to the dual role it plays in soil health and climate change mitigation. To manage SOC effectively, land managers would benefit from proxy indicators that can assess SOC concentrations and forecast changes through time. Because inputs and outputs to SOC are driven by plants and soil microorganisms, plant and soil microbial communities may be useful indicators of spatial or temporal SOC changes. To assess and compare the utility of these ecological communities as SOC indicators, we monitored SOC from surface and subsurface soils across a six-year period on a ranch in Central Coastal California, and measured plant, fungal, and bacterial/archaeal community composition. As expected, we observed unique relationships between each candidate indicator and SOC. Most notably, the relative abundance of putative copiotrophic and oligotrophic bacterial phyla allowed us to predict future changes in SOC concentration, as did the relative abundance of saprotrophic fungi and relative cover of perennial grass. Plant and soil microbial community structure was also related to SOC content at the time of sampling. Combining indicators improved our ability to predict SOC concentration and future changes, though we were unable to identify indicators that strongly explained historical changes in SOC concentration that preceded sampling. Our findings suggest that measurements of plant and soil microbial community structure can indicate SOC concentration and future changes, and so may be useful to inform management of healthy soils.

Climatic influences on survival and reproductive transitions of big-eared woodrats in California oak woodland

AbstractIt is known that climatic factors can influence the reproductive performance of small mammal populations. However, this information has not been available for the big-eared woodrat (Neotoma macrotis), a keystone species that inhabits the California central coast ranges south to Mexico and the oak woodlands (Quercus spp.) of the western Sierra Nevada foothills. From 2002 to 2014, we livetrapped woodrats on 1.1-ha study plots in coastal-central California and recorded their age and reproductive status. We analyzed these data by a capture-mark-recapture (CMR) framework to estimate state-specific recapture probability (p) and monthly apparent survival (S) of juvenile, non-reproductive, and reproductive adult female woodrats, and the influence of rain and temperature on S and transition probability (Ψ) of the three states. Rainfall from the previous season did not markedly affect survival rates of the states, with one exception: it decreased the survival of nonreproductive woodrats. Nearly all breeding occurred during the cool, wet winter season. Juvenile woodrats had at least a 0.55 probability of breeding by their first winter, conditional on survival. Temperature during the breeding season had a marked negative influence on transition probability. During winter, survival of nonreproductive adult females was significantly higher than for juvenile and reproductive females, indicating a cost of reproduction. Physiological effects and diminished diet quality due to further climate warming could reduce the reproductive success of female big-eared woodrats with negative consequences on population growth and persistence.

Modeling spatial distributions of Amah Mutsun priority cultural plants to support Indigenous cultural revitalization

AbstractAlong the Central Coast of California, USA, native plant biodiversity has depended on various forms of Indigenous stewardship such as burning, tilling, and gathering. Simultaneously, the Amah Mutsun Tribal Band (the Tribe) depends on these native ecosystems for cultural survivance. However, much of the knowledge related to the location and caretaking of cultural plants has become dormant in the community due to the immediate and ongoing effects of Euro‐American colonization. We identified potential gathering areas by modeling the spatial distributions of 10 culturally important plants throughout the Tribe's stewardship area. We utilized community science datasets with an ensemble modeling approach that combines the results of five machine learning models to predict not only the distribution of each species, but also the relative certainty of those predictions spatially. Our results revealed that 265.2 km2 (2.1%) of the Tribe's stewardship area is predicted habitat for seven or more of these cultural plants, and that the Tribe has potential access to approximately a third of these high‐priority areas. Our findings will directly inform the Tribe's cultural revitalization and ecological stewardship programs. We show how geospatial models can support the revitalization of an Indigenous culture by renewing relationships with cultural plants.

Spatial distribution of seawater carbonate chemistry and hydrodynamic controls in a low-inflow estuary

Coastal and estuarine systems play an important role in the global carbon cycle and often have complex carbonate chemistry dynamics due to a multitude of biogeochemical and physical drivers. Compared to classic estuaries, mechanisms driving the distribution of carbonate parameters in low-inflow estuaries are understudied. The spatial distribution of carbonate chemistry and hydrodynamic parameters were characterized in Morro Bay, a short and seasonally hypersaline estuary on the Central California Coast, during the dry, low-inflow season to better understand in situ modifications. Sampling transects were completed in the main channel in June, August, and September of 2018, bracketing both a high and low tide on each date. Temperature, salinity, total alkalinity, and dissolved inorganic carbon all increased from the mouth to the back of the estuary, with larger values observed during the low tide. pH values decreased towards the back of the bay, and had little variation between high and low tide for June and August transects. Flushing times (estimated using a salt-budget model approach) also increased toward the back of the bay which led to hypersaline conditions. Salinity alone only explained 20–33% of observed changes in total alkalinity and 13–22% of observed changes in dissolved inorganic carbon throughout the bay. The remaining changes in total alkalinity and dissolved inorganic carbon were likely driven by biogeochemical modifications enhanced by extended flushing times, particularly in the back bay. Prior to this project, Morro Bay experienced a recent, rapid collapse of eelgrass, the major biogenic habitat. In the last four years eelgrass in Morro Bay appears to be on a recovery trajectory; therefore, this study provides a baseline whereby future studies can evaluate carbonate chemistry changes associated with potential eelgrass recovery and expansion. This study highlights the unique hydrodynamic exchange in seasonally low-inflow estuaries and its potentially large role in influencing local carbonate chemistry and ocean acidification.