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The practical application of field or natural leaching to rice straw was evaluated with the goal of improving biomass fuel value. Observations on three rice farms in the Sacramento Valley, California indicated that potassium, chlorine and total ash are leached from rice straw by rainfall regardless of rice variety, grain harvest method, straw arrangement, or stubble length. Leaching of sulfur by natural precipitation was not clearly established. In selected field plots leached straw was successfully collected in spring, even though biomass yields were variable (2.2–3.4 Mg ha−1) and equipment had to operate in difficult conditions. Total costs for collecting leached straw on an area basis ($77.07 ha−1) are 31% higher compared to collecting crude straw in the fall ($58.67 ha−1), due to reduced performance of machinery and addition of field curing operations. Analysis of historical rainfall data for the Sacramento Valley revealed that there is an 85% probability of receiving sufficient rainfall (250 mm or more) for substantial natural leaching of straw during the winter period. The available period for mechanized collection of rice straw after the winter period ranges from 0 to 45 days, depending on drying time needed to accomplish favorable field conditions, and planting date of the next crop. The feasibility of spring collection of rice straw could be improved if straw collection equipment were better equipped to operate under wet field conditions. The commercial implementation of natural leaching of rice straw as a strategy to improve fuel quality depends on a combination of factors that include grain harvest and straw collection practices, rainfall intensity and distribution, and field-specific factors. [Copyright &y& Elsevier]

1. Recent legislation in California, USA, has restricted traditional open-field burning of rice straw residues, leading farmers to adopt alternative methods of straw disposal such as post-harvest flooding of rice fields. These changes may benefit wildlife because winter-flooded fallow rice fields provide foraging habitat to migratory waterfowl. In turn, the foraging activity of waterfowl may help to increase rice straw decomposition, providing a reciprocal benefit to farmers. We examined the effects of waterfowl foraging activity on straw decomposition and nitrogen mineralization following rice harvest in a fallow flooded soil. 2. Experimental plots (25 m2 ) were established on a silty clay soil and were subjected to two post-harvest treatments: wet-rolled or untilled. Mallard ducks Anas platyrhynchos were placed in one-half of the experimental plots, following a split-plot design, for a 3-week period, at a density equivalent to 33 birds ha-1 over a season of 180 days to approximate regional abundance data. 3. Waterfowl foraging activity increased residual surface straw decomposition by 78% in untilled plots and 18% in wet-rolled plots compared with the respective unforaged plots. Average straw diameter in foraged plots was reduced to one-third that of unforaged plots. 4. Waterfowl foraging and field tillage reduced nitrogen (N) concentrations in the surface straw residue remaining at the end of the winter fallow period. Below-ground organic residue was not affected by waterfowl foraging, indicating that ducks did not incorporate the straw. There were no apparent additions of carbon (C) or N to the soil as a result of waterfowl activity. 5. We conclude that waterfowl foraging can substantially increase straw decomposition in flooded, fallow, rice fields. Accordingly, rice producers should consider agronomic practices that attract waterfowl, such as winter flooding, to maximize the decomposition of rice straw residue. At the upper end of... [ABSTRACT FROM AUTHOR]

An assessment of the impact of three rice straw management options on the emission of greenhouse gases showed that the present defacto practice of straw incorporation into the soil would increase the emission of CO[sub 2] equivalent by about 4 times over the pre-1991 unlimited open-field burning practice. Large-scale use of rice straw for the co-manufacture of paper and energy would provide a substantial net reduction of greenhouse gas emission arising from rice cropping and subsequent disposal of the straw. If there is an active trading market for CO[sub 2] credit, the valuation could range from $0.85 million to $1.7 million annually for California rice farming. [ABSTRACT FROM AUTHOR]

To reduce soil erosion after fires, forest managers commonly employ rehabilitation treatments, including application of grass seed or mulching with straw. In 1999 the Megram fire burned 24,000 ha of mixed conifer/tanoak forest in northern California, USA. In the subsequent year, some areas were aerially seeded with barley and others were mulched with rice straw; some areas received both treatments. We investigated how these treatments affected these aspects of ecological recovery: (a) the introduction of non-native plants, (b) percent vegetative cover, (c) the diversity and density of regenerating native plants, and (d) the density and frequency of conifer seedlings. We found that mulched quadrats had a significantly higher occurrence of non-native species than untreated quadrats did. In addition, we found little evidence that mulching or mulching+seeding facilitated recovery of the native plant community. Percent vegetative cover was no higher in treated quadrats than in untreated quadrats. While annuals were present in significantly higher densities in the mulched+seeded quadrats compared to the other treatments, perennial density and overall plant density were not affected by treatment. Mulching and mulching+seeding significantly reduced the density and frequency of conifer seedlings. While we found similar native species richness on a per-quadrat basis for all three treatments, the cumulative number of native species in untreated quadrats taken as a whole exceeded the numbers found in mulched-only and mulched+seeded quadrats. We recommend that managers take steps to assure that mulch is free of non-native seed, and that further efforts be made to investigate systematically aspects of ecological recovery after the application of rehabilitation treatments. [Copyright &y& Elsevier]

Examines the influence of winterfallow flooding and straw residue incorporation on soil organic matter (SOM) pools of rice (Oryza sativa) in California. Sustainability of nitrogen fertility on rice; Types of SOM fractions; Characteristics of soil used in the study.

BACKGROUND In California, rice fields are flooded over the winter months (November to March) to facilitate degradation of post-harvest rice straw and to provide temporary habitat for migratory waterfowl. Prior research showed that winter flood rice fields had fewer rice water weevil ( Lissorhoptrus oryzophilus) , larvae and pupae during the rice production season than fields that were left unflooded in the winter. A series of experiments were conducted to provide further support for these trends under controlled conditions and to find a mechanism for this phenomenon. RESULTS Under winter flooded conditions there was a 50% reduction in populations of weevil immatures compared with the untreated control (no straw or winter flood). These same conditions corresponded to a 20% increase in the amount of silicon found in plant tissues in 2014 and a 39 to 90% decrease in methane production in the soil from 2013 to 2014, respectively. CONCLUSION Evidence from previous field research and these controlled studies supports winter flooding as an appropriate tactic for controlling L. oryzophilus populations in the spring. However, the mechanism that would explain why winter flooding adversely affects L. oryzophilus immatures remains unclear. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The Oceano Dunes near Pismo Beach, California is part of a large transgressive dune system that extends up to 5 km inland and hosts a state park that has been managed for off‐highway vehicle recreation since 1982, although vehicle activity has existed in the dunes for almost 90 years. As a result, foredunes have been largely obliterated and sand surfaces in vehicle use areas are highly emissive of dust‐sized particles, causing frequent exceedances of state air quality standards. To reduce dust emissions from the dunes, a nature‐based foredune restoration strategy using five different treatments over a 20‐ha site was implemented in February 2020. The research hypothesis is that treatments will differ in their ability to promote deposition and dune development and that more intensive planting‐based treatments will outperform simpler treatments. We test this using biannual high‐resolution uncrewed aerial system (UAS) surveys to quantify sediment budgets, sand exchanges between beach, foredune, and backdune components, changes in plant cover, and related dune development over a 2‐year period (October 2019–2021). After two full wind and plant‐growth seasons, results show that all treatments are maintaining a positive sediment budget (net accumulation), most are developing sizable nebkha dunes (an important stage in foredune development in this region), and some are increasing plant cover and species richness. There is no clear winner, yet two treatments (broadcast native plant and sterile grass seeds, and a high‐density straw planting node with native seedlings) are performing well toward developing an incipient foredune. These results will inform an adaptive management process that could entail further modifications to enhance foredune development. Based on this experience, and with reference to other types of restoration projects, we refine existing criteria used to assess the performance of "dynamic" dune restoration efforts to include settings that involve revegetation (vs. devegetation) as a means for foredune re‐establishment. [ABSTRACT FROM AUTHOR]

Agricultural waste grains are significant for providing nutrients for wintering waterfowl in California. Rice and corn comprise 56% of their nutrient needs in the Central Valley and changes to agricultural practices, such as postharvest treatments, could impact these food resources. Currently, limited data exist on how postharvest treatments in rice and corn fields affect the abundance of waste grain, yet these data are essential to determine the carrying capacity of agricultural lands for wintering waterfowl. To address this knowledge gap, we estimated the abundance of waste grain (kg/ha) using dry field transects, dry field soil cores, and flooded field (wet) soil cores. In 2016 and 2017, we sampled 84 rice fields and 47 corn fields. Our results indicate that the abundance of waste rice varied significantly among postharvest treatments. Fields that received no postharvest treatment (stubble left standing; no incorporation of straw) had the greatest amounts of waste rice, whereas fields that were disced, disced and rolled, or burned provided the least amount of waste rice. The average abundance of waste rice across all postharvest treatments was 320 kg/ha in dry fields (arithmetic mean; geometric mean = 228 kg/ha; soil core samples). Estimates of waste rice in flooded fields averaged only 169 kg/ha (geometric mean 98 kg/ha; soil core samples), significantly lower than in the same fields prior to flooding. Variation in the abundance of waste corn was greater than that of waste rice. Fields that did not receive any postharvest incorporation had the greatest abundance of waste corn, 233 kg/ha on average (arithmetic mean; geometric mean = 72 kg/ha), whereas fields that were incorporated (disced or disced and rolled) contained significantly lower abundance of waste corn, averaging 50–60 kg/ha (arithmetic mean; geometric mean = 5–10 kg/ha). The average, across all postharvest treatments, was 159 kg/ha of waste corn (geometric mean = 25–34 kg/ha). Our results suggest that postharvest practices affect the abundance of waste grain in rice and corn fields; changes in these practices could impact food availability for wintering waterfowl. Our results also indicate that the method of sampling waste grain can influence estimates of residual grain abundance. [ABSTRACT FROM AUTHOR]

The article presents a study on the seasonal level concentrations and field-scale losses of dissolved organic carbon (DOC) and total dissolved solids (TDS) in rice fields in Sacramento, California. It attempts to determine the seasonal DOC and TDS concentrations in rice field irrigation canals and drain water, measure the flow-weighted concentrations and fluxes of the DOC and TDS, and detect the principal causes of the fluxes. In the study, the rice grower fields in Northern California, including the grower sites near Arbuckle, Biggs, Marysville, and Willows, were evaluated regardless of the condition of the site, and the type and characteristic of the soil. It shows that the rice field drain water is not the cause of high concentrations of DOC in the Sacramento Valley.

Presents information on California Agriboard LLC, a private California corporation which is scheduled to start the production of medium-density fiberboard (MDF) in its Willows, California facility in 2005. Use of rice straw as the feedstock for producing MDF; Details of how the company started; Discussion on the popularity of MDF.

Stable flies (Stomoxys calcitrans) are blood-sucking insects commonly associated with cattle production systems worldwide and are known to cause severe irritation to cattle due to painful bites. Cattle react to biting stable flies with an aggregating behavior known as bunching. Bunching behavior reduces grazing or feed consumption and thus reduces cattle productivity and welfare. Cattle's fly-repelling behaviors include foot stomping, head tossing, tail switching and skin twitching. A longitudinal study was conducted in 2017 on 20 California dairies (average lactating herd size = 2,466 (SE±28.392)) during the stable fly season from April to July. The study objectives were to estimate the association between environmental factors and dairy characteristics including facility design, feed and manure management, total mixed ration (TMR) components fed to cattle, and operational pest management procedures and the outcome stable fly activity on California dairies. Stable fly activity was measured by counting stable flies on cow forelimbs (leg count) and on Alsynite traps (trap count) over the 13-week study period. Weekly leg counts were performed for cattle in lactating cow pens (31 pens from 10 study dairies) with counts made during the morning (AM) and again during the afternoon (PM). Trap counts were performed on all 20 study dairies. Data were analyzed using linear mixed models which revealed temporal variation in the average leg and trap counts with stable fly activity increasing from May to June and then decreasing to the lowest activity in July. Leg counts were higher during the afternoon compared to morning. Ambient temperatures ≤30⁰C and relative humidity (RH) measurements <50% were associated with higher leg and trap counts. Traps located at the periphery of study dairies had higher stable fly counts compared to traps located in the interior of the dairy. Cow pens with trees on the periphery had higher leg counts in comparison to pens away from trees. Specific TMR components were associated with both leg and trap counts. Dairies feeding by-products including almond hulls, wet distillers' grain, fruits, and vegetables had higher trap counts compared to dairies that did not feed these ingredients. At the pen level, pens with rations that contained straw had lower average leg counts compared to pens fed with rations that did not contain straw. A similar association was observed for pens with rations that contained wheat silage when ambient temperatures were ≤30⁰C. In contrast, pens with water added to the TMR while the RH was ≥50% had higher average leg counts compared to pens without water added to the TMR. Dairies that applied insecticides for fly control to their entire facility had lower trap counts compared to dairies that did not apply insecticides. Stable fly activity measured on California dairies using leg and trap counts varied according to the month, environmental factors, pen surroundings, trap location, TMR components, and insecticide use. [ABSTRACT FROM AUTHOR]

Objective: To describe gun shows and assess the impact of increased regulation on characteristics linked to their importance as sources of guns used in crime. Design: Cross-sectional, observational. Subjects: Data were collected at a structured sample of 28 gun shows in California, which regulates these events and prohibits undocumented private party gun sales; and in Arizona, Nevada, Texas and Florida-all leading sources of California's crime guns-where these restrictions do not exist. Main outcome measures: Size of shows, measured by numbers of gun vendors and people in attendance; number and nature of guns for sale by gun vendors; measures of private party gun sales and illegal surrogate (‘straw’) gun purchases. Results: Shows in comparison states were larger, but the number of attendees per gun vendor was higher in California. None of these differences was statistically significant. Armed attendees were more common in other states (median 5.7%, interquartile range (IQR) 3.9-10.0%) than in California (median 1.1%, IQR 0.5- 2.2%), p=0.0007. Thirty percent of gun vendors both in California and elsewhere were identifiable as licensed firearm retailers. There were few differences in the types or numbers of guns offered for sale; vendors elsewhere were more likely to sell assault weapons (34.9% and 13.3%, respectively; p=0.001). Straw purchases were more common in the comparison states (rate ratio 6.6 (95% CI 0.9 to 49.1), p = 0.06). Conclusions: California's regulatory policies were associated with a decreased incidence of anonymous, undocumented gun sales and illegal straw purchases at gun shows. No significant adverse effects of these policies were observed. [ABSTRACT FROM AUTHOR]

Postharvest waste seed from cereal grains is a major dietary component of waterfowl in the Klamath Basin in northeastern California and southeastern Oregon, a region that plays host to over a million waterfowl annually. Understanding food abundance is critical to local waterfowl management; therefore, we conducted a study in 2008 to investigate waste grain densities in barley, oat, and wheat fields. We used hierarchal mixed effect models to assess several factors that may affect waste grain densities postharvest. We also compared the effects of residue management practices to measure the effect of these treatments. To understand the scope of postharvest practices, we conducted a weekly road survey to document treatments applied to fields in our study area. We found that region best explained the variance of postharvest waste grain in barley fields, where the Tule Lake region had 89% greater densities than Lower Klamath. Neither harvester age nor baling affected waste grain in oats fields. In wheat fields, the model containing region and lodging ranked highest, where the Tule Lake region had 66% greater waste densities than Lower Klamath, and lodging increased waste grain by 70%. Burning did not reduce waste grain in barley or oat fields. Chisel-disking reduced waste grain by 94% in wheat fields compared with postharvest. Our field treatment survey found that 70% of barley fields were untreated while 18% were disked and 13% were burned and flooded. We estimated that 82% of oat fields were burned postharvest, while 18% were burned and flooded. In wheat, 61% of fields were left untreated, while 16% were disked, 8% were chisel-plowed, and 7% were flooded postharvest. Flooding and burning occurred primarily on National Wildlife Refuges, while disking, chisel-plowing, and postharvest irrigation occurred solely on private properties. Our results indicate that reducing tillage treatments would boost accessibility of cereal grain food resources to waterfowl in the Klamath Basin, and incentives to flood grain fields on private properties should be considered for the same purpose when and where possible. [ABSTRACT FROM AUTHOR]

Control of weeds in cultivated crops is a pivotal component in successful crop production allowing higher yield and higher quality. In rice‐growing regions worldwide, weedy rice (Oryza sativa f. spontanea Rosh.) is a weed related to cultivated rice which infests rice fields. With populations across the globe evolving a suite of phenotypic traits characteristic of weeds and of cultivated rice, varying hypotheses exist on the origin of weedy rice. Here, we investigated the genetic diversity and possible origin of weedy rice in California using 98 simple sequence repeat (SSR) markers and an Rc gene‐specific marker. By employing phylogenetic clustering analysis, we show that four to five genetically distinct biotypes of weedy rice exist in California. Analysis of population structure and genetic distance among individuals reveals diverse evolutionary origins of California weedy rice biotypes, with ancestry derived from indica, aus, and japonica cultivated rice as well as possible contributions from weedy rice from the southern United States and wild rice. Because this diverse parentage primarily consists of weedy, wild, and cultivated rice not found in California, most existing weedy rice biotypes likely originated outside California. [ABSTRACT FROM AUTHOR]

In this article, we examine the California South Coast Marine Life Protection Act Initiative stakeholder process, evaluate its shortcomings, and consider what could have been done differently. Our objective is to make recommendations to improve future multi-stakeholder marine policy processes. In our view, while the South Coast stakeholder process had many positive outcomes, it failed to reach what we call here a 'stable agreement.' Our analysis is based on two of the authors' involvement (one as a facilitator and the other as a stakeholder representative) in the process and a post-hoc survey of participants. We find that several ill-advised process design and management choices significantly destabilized the negotiations, leading to an ultimately unstable agreement. We highlight four major problematic process design and management decisions, including the following: representation on the multi-stakeholder group was imbalanced, the pre-meeting caucuses were not paired with training in interest-based negotiation, adequate incentives to negotiate toward a consensus agreement were not provided, and the use of straw voting at one point in the process was unclear and inconsistent. As a result of these and other process design and management flaws, many stakeholders believed that the process was biased and that their ends would be better achieved by anchoring negotiations and engaging in positional bargaining. Ultimately, this meant that near-consensus on a single cross-interest marine protected area proposal was not reached, the scientific guidelines put forth were not fully met, the process was not and is not viewed as fair by the stakeholders directly or indirectly involved, and the marine protected area regulations lack broad-scale support. These pitfalls of the South Coast stakeholder process could have been avoided had the management and facilitation team consistently followed best practices in dispute resolution. We recommend that future marine planning processes learn from this example, particularly those occurring in highly complex, urban ocean environments. [ABSTRACT FROM AUTHOR]

Examines the soil water retention properties of mines surface in the Mojave Desert in California. Challenges of revegetation in arid environments; Factors affecting soil water availability; Improvement of water infiltration in heap leach revegetation.

California has a long history of damage from postfire flooding and debris flows, often described as the fire-flood sequence. Post-wildfire assessment has been conducted on California's non-federal lands for more than 60 years. From 1956 to 1999, the focus was on aerial grass seeding for emergency revegetation. Later, hillslope treatments including straw mulch and hydromulch were shown to be more effective in reducing erosion, but their high cost make them generally infeasible. In the 1990s the state moved away from aerial grass seeding and embraced a dual strategy for minimizing post-fire impacts. First, fire suppression repair work became consistently applied to all fires. Typical repairs include installing waterbreaks on firelines, grading roads, removing soil from crossings, and mulching mechanically disturbed areas near streams. Second, there was greater use of interdisciplinary teams to evaluate lifesafety and property threats from debris flows, flooding, and rockfall on non-federal lands. The state process was pioneered by the California Geological Survey (CGS) in 1993 and has benefited from advances in spatially explicit modeling since 2000. Currently, state teams are co-led by the California Department of Forestry and Fire Protection and CGS, with evaluations only conducted on fires with significant threats. This approach is effective for rapidly notifying emergency management agencies of hazards, helping to protect lives and property. This process will benefit from further technological advances, monitoring, and improved modeling. Strategies for improving post-fire hazard evaluation and better emergency preparedness through pre-fire hazard mitigation planning are provided. [ABSTRACT FROM AUTHOR]

To ensure environmental sustainability of crop production, there is currently a growing interest in exploring the benefits and opportunities in the usage of organic amendments, аs an alternative to mineral fertilization. Organic fertilization can enhance plant nutrition, increase yields and quality, protect soil fertility. The use of test cultures allows an adequate rapid response to changes in plant nutrition. They aim to optimize plant nutrition, increase yields and product quality, protect soil fertility. The use of test cultures allows an adequate rapid response to changes in diet. Lettuce is a crop with short vegetation and intensively absorbs nutrients from the soil. She reacted positively to both mineral and organic fertilization. The experiment was carried out under controlled conditions with lettuce grown on Leached Cinnamon Forest Soil (Chromic Luvisol). The influence of 6 organic soil organic amendments on plant growth and yield was tested. These include ready-made vermicompost compost and initial substrates - manure, sludge, straw in different maturation periods. In the variants with the highest potassium content in the soil after composting - compost from California worms and fresh manure, the highest yield of lettuce was reported (189.48 g and 188.52 g, respectively). A positive correlation was found between the content of K2O in the soil and the reported yield of lettuce (R² = 0.4109). [ABSTRACT FROM AUTHOR]

Methylmercury (MeHg) is a human and environmental toxin produced in flooded soils. Little is known about MeHg in rice (Oryza Sativa L.) fields in Sacramento Valley, California. The objectives of this study were to quantify mercury fractions in irrigation water and within rice fields and to determine their mercury pools in surface water, soil, and grain. Soil, grain, and surface water (dissolved and particulate) MeHg and total mercury (THg) were monitored in six commercial rice fields throughout a winter fallow season and subsequent growing season. Both dissolved and particulate mercury fractions were higher in fallow season rice field water. Total suspended solids and particulate mercury concentrations were positively correlated (r = 0.99 and 0.98 for THg and MeHg, respectively), suggesting that soil MeHg was suspended in the water column and potentially exported. Dissolved THg and MeHg concentrations were positively correlated with absorbance at 254 nm (r = 0.47 and 0.58, respectively) in fallow season field water. In the growing season, fields with higher irrigation water MeHg concentrations (due to recycled water use) had elevated field-water MeHg (r = 0.86) and grain MeHg concentrations (r = 0.96). Based on a mass balance analysis, soil mercury pools were orders of magnitude larger than surface water or grain mercury pools; however, fallow season drainage and grain harvest were the primary pathways for MeHg export. Based on these findings, reducing (1) discharge when water is turbid, (2) straw inputs, and (3) use of recycled irrigation water could help reduce mercury exports in rice field drainage water., (© 2024 The Authors. Journal of Environmental Quality © 2024 American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.)

Firearm-related violence is a significant public health and public safety problem for cities in the USA, and licensed firearm retailers are an important source of the guns used in that violence. Using a scripted telephone interview, we screened a sample of licensed retailers in California to assess their willingness to participate in the surrogate or “straw” purchase of a handgun; such purchases are illegal under federal law. Of 149 retailers who provided a response, 30 (20.1%) agreed to participate. In multivariate analysis, pawnbrokers were more likely to agree than were gun dealers (odds ratio 6.58, 95% confidence interval 1.99–21.71). Sales of handguns that were later subjected to ownership tracing (a proxy measure for a gun’s use in crime) were not more frequent among retailers who agreed to participate than among others, and other findings were unexpected as well. [ABSTRACT FROM AUTHOR]

Stormwater is increasingly being valued as a freshwater resource in arid regions and can provide opportunities for beneficial reuse via aquifer recharge if adequate pollutant removal can be achieved. We envision a multi-unit operation approach to capture, treat, and recharge (CTR) stormwater using low energy, cost-effective technologies appropriate for larger magnitude, less frequent events. Herein, we tested nutrient, metal, and trace organic contaminant removal of a pilot-scale CTR system in the laboratory using biochar-amended woodchip bioreactors following eight months of aging under field conditions with exposure to real stormwater. Replicate columns with woodchips and biochar (33% by weight), woodchips and straw, or woodchips only were operated with continuous, saturated flow for eight months using water from a watershed that drained an urban area consisting of residential housing and parks in Sonoma, California. After aging, columns were challenged for five months by continuous exposure to synthetic stormwater amended with 50 μg L−1 of six trace organic contaminants (i.e., fipronil, diuron, 1H-benzotriazole, atrazine, 2,4-D, and TCEP) and five metals (Cd, Cu, Ni, Pb, Zn) frequently detected in stormwater in order to replicate the treatment unit operation of a CTR system. Throughout the eight-month aging and five-month challenge experiment, nitrate concentrations were below the detection limit after treatment (i.e., <0.05 mg N L−1). The removal efficiencies for metals in all treatments were >80% for Ni, Cu, Cd, and Pb. For Zn, about 50% removal occurred in the woodchip-biochar systems while the other systems achieved about 20% removal. No breakthrough of the trace organic compounds was observed in any biochar-containing columns. Woodchip columns without biochar removed approximately 99% of influent atrazine and 90% of influent fipronil, but exhibited relatively rapid breakthrough of TCEP, 2,4-D, 1H-benzotriazole, and diuron. The addition of straw to the woodchip columns provided no significant benefit compared to woodchips alone. Due to the lack of breakthrough of trace organics in the biochar-woodchip columns, we estimated column breakthrough with a diffusion-limited sorption model. Results of the model indicate breakthrough for the trace organics would occur between 10,000 and 32,000 pore volumes. Under ideal conditions this could be equivalent to decades of service, assuming failure by other processes (e.g., clogging, biofouling) does not occur. These results indicate that multiple contaminants can be removed in woodchip-biochar reactors employed in stormwater treatment systems with suitable flow control and that the removal of trace organic contaminants is enhanced significantly by addition of biochar. Image 1 • 13-month pilot-scale stormwater treatment system evaluated contaminant removal. • Woodchips and biochar effectively removed nitrate, metals and organic contaminants. • Contaminant breakthrough was predicted to occur after at least 10,000 pore volumes. [ABSTRACT FROM AUTHOR]

Elasmobranchs are common, iconic species in public aquaria; their wild counterparts are key members of marine ecosystems. Post-mortem examination is a critical tool for disease monitoring of wild elasmobranchs and for management of those under human care. Careful necropsy of the head, with a focus on clinically relevant anatomy, can ensure that proper samples are collected, increasing the chance of presumptive diagnoses prior to slower diagnostic workup. Immediate feedback from a thorough head necropsy allows for faster management decisions, often identifying pathogens, routes of pathogen entry, and pathogenesis, which are current shortcomings in published literature. This article proposes a protocol for necropsy of the elasmobranch chondrocranium, emphasizing unique anatomy and careful dissection, evaluation, and sampling of the endolymphatic pores and ducts, inner ears, brain, and olfactory system as part of a complete, whole-body necropsy. Extensive use of cytology and microbiology, along with thorough sample collection for histology and molecular biology, has proven effective in identifying a wide range of pathogens and assisting with characterization of pathogenesis. The cause of mortality is often identified from a head necropsy alone, but does not replace a thorough whole-body dissection. This protocol for necropsy and ancillary diagnostic sample collection and evaluation was developed and implemented in the necropsy of 189 wild and aquarium-housed elasmobranchs across 18 species over 13 years (2011--2023) in California. Using this chondrocranial approach, meningoencephalitis was determined to be the primary cause of mortality in 70% (118/168) of stranded wild and aquarium-housed elasmobranchs. Etiology was largely bacterial or protozoal. Carnobacterium maltaromaticum bacterial meningoencephalitis occurred in salmon sharks (Lamna ditropis), shortfin mako sharks (Isurus oxyrinchus), common thresher sharks (Alopias vulpinus), and one Pacific electric ray (Tetronarce californica). Miamiensis avidus was the most common cause of protozoal meningoencephalitis and found almost exclusively in leopard sharks (Triakis semifasciata) and bat rays (Myliobatis californica) that stranded in San Francisco Bay. Bacterial pathogens were found to use an endolymphatic route of entry, while protozoa entered via the nares and olfactory lamellae. Trauma was the second most common cause of mortality and responsible for 14% (24/168) of wild shark strandings and deaths of aquarium-housed animals. [ABSTRACT FROM AUTHOR]

The tadpole shrimp (Triops longicaudatus (Leconte); Notostraca; Triopsidae) is a vernal pool crustacean that has emerged as a significant pest for many rice farmers in California. Currently, lambda-cyhalothrin is the commercial standard and sole management practice forTPS, but resistance appears to be emerging. Field and laboratory trials were conducted from 2015 to 2018 at the Rice Experiment Station in Biggs, California, and in greenhouses at the University of California (UC) Davis to evaluate the efficacy of several alternative chemical controls and to explore early indicators ofTPS activity and damage as monitoring tools.TPS mortality in plots treated with azadirachtin was not significantly different from those in the untreated control across all trials. Copper sulfate, lambda-cyhalothrin, and clothianidin were consistently effective across both lab and field trials. Chlorantraniliprole generated effective control in four of the five trials, whereas two diflubenzuron rates generated adequate control in the field, but not in laboratory bioassays.Thus, there appear to be several effective alternative control options available for farmers, should resistance to lambda-cyhalothrin continue to spread. Water turbidity (measured using a scale of 1–4) and the number of dislodged seedlings were both significantly correlated with TPS counts in field studies. Turbidity exhibited the highest correlations with TPS counts, suggesting that with further refinement it could play a valuable role in monitoringTPS populations. [ABSTRACT FROM AUTHOR]