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  • Surfer rainfall study helps focus water-quality discussion

    September 12, 2016:

    SCCWRP and its partners have completed a three-year epidemiological study examining the health impacts of entering coastal waters during and shortly after rainfall, a study that has raised important public policy questions about whether existing water-quality standards are protecting beachgoers during wet weather.

    The Surfer Health Study, which tracked the illness rates of 654 San Diego-area surfers during the rainy winter season, found that surfers experienced increased rates of both gastrointestinal illness and other illness symptoms when they surfed during rain events and/or in the three days that followed. 

    However, when the illness data were correlated with quantitative measurements of aquatic microbial contamination at two popular San Diego surfing spots, the rate at which surfers contracted gastrointestinal illness was lower than the illness rate predicted under federal guidelines. The guidelines, which were issued by the U.S. Environmental Protection Agency in 2012, predict the relationship between gastrointestinal illness rates and corresponding microbial contamination levels.

    Given these findings, water-quality managers are now tasked with determining what additional clean-up actions are needed to reduce the illness rates documented in San Diego.

    Rainfall makes Southern California’s coastal zone particularly susceptible to waterborne contamination, as the pathogens that can make people sick wash off the land and travel through storm drains to the beach. Although most Southern California beachgoers heed warnings by public health officials to stay out of the water following rainfall, surfers are a notable exception; thousands are attracted to the favorable surf conditions that accompany storm events. 

    During the study, which was conducted during the winters of 2013-14 and 2014-15, San Diego surfer volunteers were asked to use a smartphone app to confidentially  
    report their daily surfing activities and symptoms of illness. They received gift certificates to a surfing retailer for their participation. 

    Study participants logged a combined 10,081 surfing sessions; 13% of these sessions took place during wet-weather conditions, making the beach epidemiology study one of the largest of its kind in the past 30 years.

    The study documented an excess gastrointestinal illness risk of 12 cases per 1,000 for surfers who entered the water in wet weather, for a total of 30 cases per 1,000. The EPA’s water-quality criteria, however, specify that there are to be no more than 32 to 36 excess cases per 1,000.

    The full epidemiology study has been published on SCCWRP’s website. For more information, contact Ken Schiff.  

    Surfers paddle away from the shore during a sunny winter morning at Ocean Beach in San Diego,
    just one day after a torrential downpour. Scientists want to know the extent to which rainfall runoff
    in coastal ocean waters is making ocean bathers sick.

    San Diego's Tourmaline Surfing Park is at the receiving end of a storm drain channel, making it
    susceptible to land-based runoff during rainfall.

  • Method comparison study seeks to assess utility of using DNA to identify stream algae

    August 05, 2016:

    SCCWRP and its partners have launched a first-of-its-kind study to determine whether DNA-based methods can reliably be used to identify algae in wadeable streams across California, a finding that could pave the way for the incorporation of molecular technology into stream bioassessment monitoring statewide.

    Stream managers across Southern California already use the composition of stream algal communities to evaluate overall water body condition, but these assessments are dependent on trained taxonomists to identify algae samples individually. This manual identification process is labor-intensive, costly and prone to backlogs.

    Switching to an algal analysis method that allows algae samples to be identified through DNA sequencing could reduce dependence on a limited supply of algal taxonomists, as well as provide important new insights about novel algae species and their habitats. 

    In January, SCCWRP and its partners began laying the groundwork to compare the effectiveness of morphology vs. DNA-based algae identification methods. The study is ongoing.

    The need for improved stream algae bioassessment methods is growing in California. For the past six years, state water officials have been working to develop a statewide stream biointegrity and nutrient policy that is expected to rely, in part, on algae-based bioassessments. 

    Algal communities are valuable indicators of human impacts to streams because they are highly sensitive to physical, hydrological and geochemical changes to their environment. Excessive nutrient inputs, for example, can trigger harmful algal blooms (HABs).

    Vetting DNA-based algae bioassessment methods also could benefit the state’s Surface Water Ambient Monitoring Program (SWAMP), which is developing an algae-based stream scoring tool comparable to the California Stream Condition Index (CSCI). The CSCI, which was co-developed by SCCWRP, uses aquatic insects and other benthic invertebrates as indicators of stream condition. The statewide algal index is being built to complement the CSCI, providing an additional line of evidence for evaluating stream health.

    For the method comparison study, SCCWRP and its partners plan to assess the performance of the DNA-based identification methods across a wide range of geographic and geochemical settings. Algae samples are being collected by the Southern California Stormwater Monitoring Coalition, the San Francisco Bay Regional Monitoring Coalition, the statewide Reference Condition Management Program, and the statewide Perennial Stream Assessment. In addition, the Santa Margarita River – a watershed heavily impacted by nutrient loading – is being sampled to assess method performance through a full algae bloom-and-bust seasonal cycle.

    Study findings are expected to be released in late 2017.

    For more information, contact Dr. Susanna Theroux

    SCCWRP's Justin Vanderwal and Lisa Zumwalde wade into the Santa Margarita River 
    to collect samples of greenish algal blooms. SCCWRP and its partners are sampling the
    Santa Margarita River algae through a full boom-and-bust seasonal cycle, which will 
    provide key insights into whether DNA-based methods can reliably be used to identify 
    the algal species present.

    SCCWRP's Mayra Molina collects a sample of water in the Santa Margarita River that runs 
    through Riverside and San Diego counties. SCCWRP and its partners are sampling algae 
    in this stream and dozen of others across California for a study that will determine the
    reliability and effectiveness of using DNA-based methods to identify stream algae.

  • Cell bioassays could be effective at screening for potential harm in fish

    August 05, 2016:

    SCCWRP and its partners at the University of Florida have demonstrated in a proof-of-concept study that biological assays built with engineered human cells have the potential to be effective at screening for potential biological harm in fish exposed to differing levels of estrogen-mimicking chemicals.

    The finding, obtained in May, involved showing that there is a strong correlation between the way that engineered human cells respond to increasing levels of chemical contaminants, and the way that inland silverside fish experience increasingly severe biological effects when exposed to the same contamination.

    The ongoing linkage study – the first of its kind in a coastal marine environment – provides compelling evidence that commercially available cell bioassays are a viable technology for screening receiving waters for potentially harmful levels of CECs. Cell bioassays are commonly used in pharmaceutical and food-industry applications to rapidly screen a wide variety of chemicals for potential toxicity. 

    SCCWRP and researchers around the world are interested in adapting cell bioassays into a viable CEC screening tool because traditional methods for monitoring the impacts of CECs on aquatic life – such as targeted chemical analysis and whole-organism toxicity testing – tend to be comparatively labor-intensive and costly. These methods also tend to be unable to detect all chemicals of concern, whereas a bioassay is designed to detect dozens of chemicals that share similar biochemical properties.

    The next step in the study is to zero in on the precise chemical concentration at which the cell bioassays begin to detect an adverse biological response in fish. Knowing where this threshold lies is crucial to develop a long-term monitoring and management strategy.

    Over the long term, researchers hope to develop new bioassays and/or adapt commercially available bioassays to screen for a wide variety of CECs. Already, SCCWRP and its partners have begun working to replicate the estrogenic linkage study with glucocorticoids, a class of steroidal anti-inflammatory drugs commonly used to treat eczema and asthma. 

    For more information, contact Dr. Alvina Mehinto.

    Water-quality managers need rapid, cost-effective tools to alert them when contamination
    has the potential to adversely impact fish growth and survival. Above, the Russian River 
    in Northern California is one site where SCCWRP and its partners are testing the utility of 
    using cell bioassays to screen for potential biological effects triggered by CECs.

    SCCWRP and its partners have shown that cell-based bioassays can serve as reliable
    and sensitive tools for screening for the presence of estrogenic chemicals. Above, the cell
    assay gives a clear response signal (i.e., 50% response) in the presence of relatively low 
    concentrations of the estrogenic chemicals 17β-estradiol and nonylphenol. This response 
    was observed well before chemical concentrations rose to a level that threatens fish 
    growth and survival, indicating that cell bioassays have the potential to be adapted as an 
    effective screening method for estrogenic chemicals and other CECs.

  • SCCWRP testing new EPA health risk model at Inner Cabrillo Beach

    May 31, 2016:

    SCCWRP in late May launched a first-of-its-kind study aimed at ascertaining whether high fecal indicator bacteria Ievels at Inner Cabrillo Beach in the Los Angeles Harbor area are indicative of a health threat to beachgoers who enter the water.

    The study involves using a health risk model known as Quantitative Microbial Risk Assessment (QMRA), which was recently endorsed by the U.S. Environmental Protection Agency to quantify the risk of gastrointestinal illness from waterborne contamination at the beach. Inner Cabrillo Beach is a popular swimming area in San Pedro that receives about half a million beachgoers annually.

    For the past 15 years, beach water-quality managers have worked without success to reduce the concentration of a type of fecal indicator bacteria called Enterococcus, which is periodically found at levels that exceed water-quality guidelines. Managers have spent more than $20 million on structural and nonstructural improvements, including testing and replacing sewer collection lines and installing bird exclusion devices designed to reduce avian fecal matter.

    Performing a QMRA at the beach will offer important new insights into how much risk is associated with swimming at Inner Cabrillo Beach. If the contamination is coming from human sources, such as leaking sanitation infrastructure, it would pose a greater human health risk than if the contamination were coming from non-human sources, such as dogs and seagulls.

    QMRAs are designed to estimate health risks on a site-specific basis using a dose-response model that factors in the concentration of the pathogens in the water, the volumes of water being ingested, and the pathogens’ infectivity to humans. The EPA recommends using QMRAs only when a beach is contaminated with non-human bacterial sources.

    The SCCWRP-led study will mark the first time a QMRA has been conducted at a California marine beach in dry weather, setting a precedent for how to conduct QMRAs of this type in the future.

    For more information, contact Ken Schiff.

    Inner Cabrillo Beach in the Los Angeles Harbor area has been the subject of  more than $20 million
    in unsuccessful clean-up efforts. SCCWRP will launch a study in May to ascertain whether
    high levels of fecal indicator bacteria that remain at the beach despite cleanup efforts are indicative
    of a health threat to beachgoers. (Courtesy of Port of Los Angeles)

  • HAB experts develop statewide strategy for responding to toxic cyanobacterial blooms

    May 03, 2016:

    A group of scientific experts on harmful algal blooms in California has developed a statewide strategy for responding to HABs and mitigating their impacts in water bodies across California.

    The strategy, co-authored by SCCWRP and published in February by the State Water Board’s Surface Water Ambient Monitoring Program (SWAMP), provides a roadmap that California’s aquatic resource agencies can use to build capacity for monitoring HABs, assessing a water body’s susceptibility to these toxic blooms, and coordinating management responses.

    HABs are events that trigger production of algal toxins that can impair water quality and recreational uses, as well as threaten the health of humans, wildlife, and pets that come into contact with these toxins. Multiple water bodies in California already have been placed on the state’s 303(d) listing of impaired water bodies due to the toxins produced by HABs.

    Among the report’s recommendations is to use satellite imagery to identify these blooms, develop a centralized online database for tracking HAB events and for issuing bloom advisories, and craft consistent statewide procedures for sampling, health and safety, and quality assurance.

    The report, titled California Freshwater Harmful Algal Blooms Assessment and Support Strategy, is an outgrowth of a 2012 workshop hosted by SWAMP aimed at addressing the growing threat posed by cyanotoxins. One of the workshop’s key recommendations was to develop a long-term, statewide vision and strategic plan for responding to the issue in California.

    This strategy report is intended to serve as a conversation starter that various aquatic resource agencies can use to coordinate and implement a comprehensive strategy. SWAMP already has begun implementing many of the report’s recommendations with support from SCCWRP and others.

    For more information, contact Dr. Meredith Howard

    Pinto Lake in Santa Cruz County is tainted a murky greenish color by toxic cyanobacteria.
    HAB events in Pinto Lake have triggered the recreational water body to be placed on the 
    state's 303(d) listing of impaired water bodies. A new statewide strategy co-authored by SCCWRP
    aims to help aquatic resource managers respond to and mitigate HAB events across California.

  • Expert panel urges action on West Coast ocean acidification

    May 03, 2016:

    Global carbon dioxide emissions are triggering fundamental changes to ocean chemistry along the North American West Coast that should be addressed through immediate and decisive management actions, including development of a coordinated regional management strategy, a panel of leading ocean scientists has unanimously concluded.

    A failure to adequately respond to this change in seawater chemistry, known as ocean acidification (OA), is anticipated to have devastating ecological consequences for the West Coast in the decades to come, according to the 20-member West Coast Ocean Acidification and Hypoxia Science Panel, which published its findings in April.

    The panelists, who include two SCCWRP scientists, say they hope the findings will serve as a catalyst for coordinated West Coast management action aimed at mitigating the impacts of ocean acidification and to get ahead of future OA-related challenges.

    Already, some West Coast marine shelled organisms are having difficulty forming their protective outer shells, and the West Coast shellfish industry is seeing high mortality rates during early life stages when shell formation is critical.

    Because of the way the Pacific Ocean circulates, the North American West Coast is exposed to disproportionately high volumes of seawater at elevated acidity levels.

    In its final report, the panel recommended a number of specific, multi-agency solutions that can be implemented immediately, including:

    Exploring approaches that involve the use of seagrass to remove carbon dioxide from seawater.
    Supporting wholesale revisions to OA-related water-quality criteria.
    Identifying strategies for reducing the amounts of land-based pollution entering coastal waters. 
    Enhancing a West Coast-wide monitoring network that provides information toward development of coastal ecosystem management plans.

    More long-term recommendations include developing predictive mathematical models that provide insight into how West Coast ecosystems are impacted by ocean acidification and a related phenomenon known as hypoxia, or low dissolved oxygen levels. SCCWRP is already working in this arena by collaborating with multiple partners on the development of coupled physical and biogeochemical ocean models that estimate OAH impacts from global carbon dioxide emissions, natural upwelling process and nutrients introduced via local discharges.

    The Panel was convened in 2013 to explore how West Coast government agencies could work together with scientists to combat the effects of ocean acidification and hypoxia.

    For more information, contact Dr. Steve Weisberg