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  • Microbes in sewer pipes to be studied to glean insights about origins of fecal contamination

    February 08, 2018:

    SCCWRP and its partners have launched a study investigating whether the microbial community that grows inside sanitary sewer pipes could provide insights into the origins of human fecal contamination found in aquatic environments across Southern California.

    The study, launched in January, will examine whether the microbial community growing on the inner surfaces of the City of San Diego’s public sewer pipes is unique to this type of infrastructure, a finding that could help researchers discern whether leaking sewer pipes are responsible for human fecal contamination in urban waterways in the San Diego area.

    Researchers at the University of Wisconsin, Milwaukee, found that a unique microbial community – commonly referred to as biofilm – lives inside Milwaukee’s sewer collection pipes, making it possible for researchers to trace human fecal contamination found in the region’s waterways back to sewer pipes.

    For the San Diego study, researchers will seek to replicate Milwaukee’s approach to microbial source tracking. Working in collaboration with University of Wisconsin researchers, SCCWRP will use DNA sequencing methods to determine whether the composition of bacteria in San Diego biofilm samples is unique to the City’s sewer pipes, and whether it’s the same across various sampling sites.

    The study is motivated by a long-term goal among the region’s water-quality managers to understand whether the human fecal signals that are widely detected in San Diego-area flood control infrastructure are coming from leaky public sewer systems, from defects in privately maintained sewer lateral lines and septic systems, or from humans depositing raw fecal material directly into waterways.

    The biofilm community that lines the insides of sewer pipes is theorized to be the product of unique environmental factors, including temperature, moisture, darkness and a rich nutrient supply.
    Because biofilm grows in thin layers on the inner surface of sewer pipes, these layers are constantly sloughed off as wastewater flows through the pipes, making the microbes ubiquitous in untreated sewage.

    During the study, researchers also will examine whether the biofilm signal is strong enough to be reliably detected even when diluted. Biofilm would only be an effective microbial source tracking tool if its signal can be detected above levels of background interference in highly diluted water samples.

    If the biofilm tracking method continues to show promise, researchers also will examine whether there are any differences in this biofilm community under wet vs. dry weather conditions.
    Sampling in San Diego will continue through May, with results expected as early as this summer.

    For more information, contact Dr. John Griffith.


    Human fecal contamination has been detected in storm drain channels across the San 
    Diego area that drain to coastal waters, including Tourmaline Surfing Park, above.
    Researchers have launched a study that could provide insights into whether leaking 
    public sewer pipes could be responsible for the contamination.

  • Study launched to revisit copper TMDL for Marina del Rey Harbor

    February 08, 2018:

    SCCWRP has launched a two-year study examining whether existing regulatory targets for dissolved copper in Marina del Rey Harbor should be modified to more accurately reflect the ecological threat posed by copper.

    The study, which kicked off in January, will document the concentrations of copper that aquatic organisms in the Los Angeles County boat harbor are exposed to at different times of the year, and how toxic these copper levels are at different sites across the harbor. 

    Under the harbor’s existing Total Maximum Daily Load (TMDL) regulatory target, Marina del Rey Harbor is required to reduce copper loading by 85%, which would require boat owners to make significant changes to the types of anti-fouling paint they typically use on the underside of boats.

    Although copper in boat paint plays an essential role in preventing barnacles and other marine life from attaching and growing on the underside of boats, water quality in the boat harbor frequently exceeds the regulatory standard of 3.1 ug/L for copper. Marina del Rey is the largest man-made, small-boat harbor in California.

    The regulatory target for copper was originally set based on the results of standardized laboratory toxicity tests. However, because the tests used purified seawater, researchers don’t know if dissolved copper in Marina del Rey is as toxic to aquatic life as it would be in purified seawater. Previous research has indicated that factors such as dissolved organic carbon can influence the bioavailability of dissolved copper to aquatic life.

    The SCCWRP study will seek to use an approach endorsed by the U.S. Environmental Protection Agency to set a site-specific water-quality objective for dissolved copper. The approach enables water-quality managers to consider the effect of local water-quality characteristics on copper toxicity. 

    The site-specific objectives approach has been used to modify copper regulatory targets for San Francisco Bay, the Los Angeles River and Calleguas Creek in Ventura County.

    Also during the study, researchers will test-drive a recently developed marine version of the Biotic Ligand Model (BLM) to predict variations in Marina del Rey Harbor copper toxicity based on water-quality characteristics. A proposed revision of the EPA water-quality criteria for copper uses the BLM; this study will provide information on how well the model performs in Southern California waters.

    Sampling for the study, which began in January, is expected to continue through 2019. A draft work plan for the study will be distributed for public review in the coming months. 

    For more information, contact Steven Bay

    Barnacles, algae and other marine life attach to the underside of a boat that has been
     raised out of the water. Copper-based paints play a key role in preventing this fouling, 
    but because the copper dissolves in water, the water-quality regulatory targets for copper 
    in places like Marina del Rey Harbor have been exceeded. SCCWRP and its partners 
    are pursuing a study examining whether the regulatory target for copper should be
     modified to more accurately reflect its ecological threat.

  • Technical foundation created for ephemeral stream tools

    February 08, 2018:

    SCCWRP and its partners have completed a pair of studies that establish a technical foundation for building watershed management tools for Southern California streams that run dry for much of the year.

    The two studies, published as SCCWRP technical reports in December, provide an important proof-of-concept of the feasibility of building tools that can quantitatively assess the health of ephemeral streams, as well as that can model the hydrologic flow patterns of ephemeral streams.

    Although ephemeral streams make up about 60% of all streams in Southern California, existing watershed management tools are designed for application in perennial streams only.

    The two studies, which were conducted in the Santa Ana and San Diego regions, represent an important step forward in building a suite of ephemeral stream management tools that complement existing perennial stream tools. 

    During the ephemeral streams condition assessment study, researchers examined the composition of terrestrial arthropod and bryophyte communities living in dry streambeds. Multiple biological indicators were identified that could potentially be used to quantitatively score the condition of these ephemeral streams. 

    Based on these findings, SCCWRP and its partners are continuing to work toward developing the quantitative scoring tool for ephemeral stream condition; it is expected to be released in 2020.

    Furthermore, the ephemeral streams bioindicator data collected during the study is being used to validate the California Rapid Assessment Method (CRAM) tool for ephemeral streams, which was co-developed by SCCWRP. By validating this screening-level ephemeral streams assessment tool, California’s stream managers will have more confidence in the accuracy of the tool, encouraging more widespread adoption among California’s stream monitoring programs.

    During the ephemeral streams hydrologic mapping project, researchers adapted hydrologic models developed by the U.S. Geological Survey to predict typical monthly flows for ephemeral streams under wet, normal, and dry climatic conditions. Researchers then modeled theimpacts that human disturbances have on these flow patterns over time. 

    The resulting hydrologic maps – available as shapefiles and through an interactive web application – reveal the extent and location of ephemeral streams, as well as capture the dynamic nature of ephemeral stream flows across Southern California over time.

    The hydrologic maps have the potential to support a variety of management needs, including prioritizing sites for monitoring, providing evidence for causal assessment studies, forecasting the impacts of land-use changes and climate change, and informing the design of stream bioassessment surveys.

    SCCWRP’s work on ephemeral streams has opened the door to partnerships that will expand this science outside of California. Notably, SCCWRP is partnering with the U.S. Environmental Protection Agency and the Arizona Department of Environmental Quality to evaluate the new ephemeral streams tools for Arizona as well. 

    SCCWRP also is partnering with the EPA to evaluate field-based flow duration assessment tools across the arid Southwest that were originally developed for the Pacific Northwest.

     For more information, contact Dr. Raphael Mazor.

     

    SCCWRP and its partners have developed a series of hydrologic maps that estimate
    the historic flows of ephemeral streams. The maps above show flow conditions in the
    Santa Ana region in January, left, and July, right, under three different types of seasonal
    rainfall patterns (dry, normal, and wet). From these interactive, customizable maps,
    watershed managers can understand the dynamic nature of ephemeral stream flows
    over time.

  • Draft framework unveiled for assessing human health impacts of contaminated sediment

    November 20, 2017: SCCWRP and its partners have completed development of a standardized sediment assessment framework intended to better protect the health of humans who consume seafood caught in enclosed bays and estuaries in California.


    The draft framework, published as a SCCWRP technical report in October, is being considered for adoption by the State Water Board to define for environmental managers how to implement California’s Sediment Quality Objective (SQO) for protection of human health. 

    The human health SQO – one of three adopted by the State Water Board in 2008 for enclosed bays and estuaries – is a one-sentence regulatory target that calls on sediment contamination to not be present “at levels that will bioaccumulate in aquatic life to levels that are harmful to human health.” 

    SCCWRP and its partners have spent more than a decade conceptualizing, building and vetting the human health SQO framework to create a standardized technical definition of what it means to be in compliance with this regulatory target. 

    California’s environmental management community will be able to use the framework to inform decision-making on issues like setting appropriate sediment clean-up targets. 

    The draft framework relies on standardized, quantitative indicators of sediment contamination’s human health effects to score the quality of sediment in enclosed bays and estuaries. Indicator scores are classified into condition categories ranging from “unimpacted” to “clearly impacted.” 

    The human health framework is designed to complement California’s SQO assessment framework for the protection of sediment-dwelling aquatic life, which was adopted by the State Water Board and approved for regulatory use in enclosed bays and estuaries in 2009. Both frameworks use standardized, quantitative indicators with defined thresholds to provide consistency and statewide comparability. 

    There is not yet an approved assessment framework in place to support California’s third SQO, which applies to the protection of fish and wildlife. Under the human health SQO framework, sediment sampling sites are assessed in two main ways:

    •  Chemical exposure analysis: Sportfish tissue chemistry data are compared to the advisory sportfish tissue contamination levels developed by California’s Office of Environmental Health Hazard Assessment (OEHHA).
    • Site linkage analysis: The linkage between site sediment contamination and tissue contaminant concentration is evaluated. 
    The framework features a three-tiered assessment process that provides capability to adapt the assessment to a wide range of situations. The framework also makes use of a food web bioaccumulation model to evaluate site linkage.

     Assessments using the framework will be focused around PCBs (polychlorinated biphenyls) and chlorinated pesticides – two major chemical drivers of seafood consumption risk. 

    SCCWRP and its partners began conceptualizing pieces of the draft framework in 2005, and started developing the technical aspects in 2009 with the guidance of a scientific steering committee as the project came into sharper focus. A stakeholder advisory committee that included participation by SCCWRP member agencies also played a key role in shaping the framework.

     Final refinements to the framework, which were completed over the past year, included harmonizing tissue chemistry evaluation thresholds with OEHHA’s seafood consumption advisory tissue levels, completing a four-year test drive of the framework in the greater Los Angeles Harbors area, and refining the bioaccumulation model used to evaluate sediment contamination. 

    The State Water Board will solicit public comments on the draft framework through the end of 2017, and hold an informational public workshop on December 5, 2017 in Sacramento. The draft framework is scheduled to be considered for adoption by the State Water Board in March 2018. 

    For more information, contact Steve Bay.


    SCCWRP and its partners have developed a sediment quality framework that establishes
     a standardized technical definition of what it means to be in compliance with California’s
     Sediment Quality Objective (SQO) for the protection of human health in enclosed bays
     and estuaries. The draft framework was published as a SCCWRP technical report, above.

  • International expert panel convened to develop acidification thresholds for pteropods

    November 20, 2017: A 10-member panel made up of leading global experts on pteropods, or sea snails, convened at SCCWRP in September to develop consensus around biologically relevant thresholds at which these ubiquitous marine calcifying organisms are affected by ocean acidification (OA).


    During three days of deliberations, the international pteropod panel reached consensus on the thresholds at which various specific environmental conditions linked to more intensive OA in the California Current Ecosystem are expected to trigger specific adverse effects in pteropods and similar calcifying organisms.

     Pteropods, which depend on minerals in seawater to form their highly soluble calcified shells, are sensitive to changes in seawater chemistry, enabling them to serve as early-warning indicators for how OA can be expected to impact the health of marine ecosystems.

    The international pteropod panel is the first of three expert panels that will be convened and facilitated by SCCWRP and its partners over the next few years. Researchers’ goal is to use the consensus opinion of experts to develop an interpretation framework that coastal resource managers can use to glean ecologically relevant insights from the copious data they collect via chemistrybased measures of OA, including measuring seawater pH.

     During its deliberations, the pteropod panel agreed that the most relevant OA chemical parameter for assessing impacts to pteropods is aragonite saturation state, which reflects the concentration of a dissolved mineral called aragonite in seawater. 

    Additionally, panelists reached consensus on which key biological processes in pteropods – including shell dissolution, egg development and mortality – are critically impacted at specific aragonite saturations state thresholds. Panelists also agreed on the critical magnitudes and durations of exposure at which pteropods exhibit increasing levels of adverse biological effects, and identified data gaps and priority future research to address these gaps.

     Finally, panelists developed recommendations on how to apply their recommended biological endpoints to existing OA monitoring data and computer models that track and predict OA conditions. 

    A group of West Coast ocean modelers, including SCCWRP, is planning to immediately use the panel’s recommendations to interpret the outputs of a state-of-the-art, high resolution model that predicts which West Coast habitats and marine communities will be most vulnerable to the impacts of corrosive conditions. Coastal resource managers will be able to use this West Coast OA model to better protect and minimize ecological damage to vulnerable areas during critical periods. 

    The pteropod panel will draft a review article summarizing its consensus findings and recommendations that will be submitted to a peer-reviewed journal next year. 

    For more information, contact Dr. Nina Bednarsek.


    An expert panel of 10 leading global experts on pteropods convenes at  SCCWRP in 
    September to reach consensus on biologically relevant  thresholds for tracking the
     impacts of ocean acidification on coastal  marine health. The experts, pictured with 
    SCCWRP staff who  facilitated the panel’s deliberations, traveled from as far away
     as Great Britain, Italy and British Columbia.

  • Bight ’18 kickoff brings together dozens of agencies

    November 20, 2017: A collaboration involving dozens of environmental organizations will examine how human activities have affected the ecological health of Southern California’s coastal waters during the sixth cycle of the Southern California Bight Regional Monitoring Program, which officially kicked off in September at SCCWRP.


    Participants of the 2018 cycle of the regional marine monitoring initiative are considering featuring up to six distinct study elements – sediment quality, ocean acidification, harmful algal blooms, trash, microbial water quality and marine protected areas – that together will help paint a picture of regional ecosystem condition. 

    Bight ’18 participants are planning to repeat some of their previous regional monitoring efforts to document trends, particularly to sediment quality in the Southern California Bight. They also will ask new scientific questions that require novel measurements, testing of prototype technologies, and additional assessments that extend the program into previously unmonitored habitats. The program’s focus area encompasses more than 1,500 square miles of Southern California’s coastal waters. 

    More than 140 people representing nearly 80 organizations attended an all-day Bight ’18 kickoff meeting on September 14 at SCCWRP to begin fleshing out the management questions that the regional program will address. Potential questions were ranked and prioritized based on how environmental managers will respond once they obtain answers to these questions. At the meeting, more than 20 questions made the short list for consideration. 

    In the coming months, Bight ’18 participants will further refine the list of management questions and develop technical study designs that will ensure the program can get scientifically rigorous answers. Field sampling will begin July 1, 2018. 

    The Southern California Bight Regional Monitoring Program, which has been facilitated by SCCWRP since its inception in 1994, mobilizes Southern California environmental management agencies to collect data from across a much greater expanse than just their local discharge zones. Both regulated and regulatory agencies, as well as non-governmental and academic organizations, come together to collaboratively design the study and interpret findings. 

    Southern California’s environmental management community relies on the Bight program to better direct resources and to maintain focus on the areas and issues that are disproportionately impacted by human activities. 

    Planning and final assessment reports from the previous cycle of the Bight monitoring program, Bight ’13, are available online. For more information and to learn about becoming a Bight ’18 program participant, contact Ken Schiff.


    Participants of the Southern California Bight 2018 Regional Monitoring Program attend 
    the program’s all-day kickoff meeting at SCCWRP in September. Nearly 80 organizations 
    from across Southern California and beyond have committed to participating in the regional 
    monitoring collaboration, which examines how human activities have impacted the ecologica
    l health of Southern California’s coastal waters.