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In 2016, California passed Senate Bill (SB) 1383 to reduce short-lived climate pollutants, including methane gas. Towards this end, the law specifically mandates a 75% reduction of organic waste, including food waste (FW), from landfills by 2025. However, current infrastructural capacity to treat this diverted organic waste is limited throughout the state, so new facilities will need to be built to treat these valuable waste flows. The purpose of this study is to investigate ideal size and scale of new facilities that maximize FW treatment and minimize GHG emissions. To do so, this study uses a case study of Los Angeles County to model a decentralized network of small-scale, containerized anerobic digestors (ADs) for treatment of FW in the region. A spatial FW dataset developed for this study is used with a novel iterative-descent clustering model to simulate potential “FW-sheds” of ADs using Geographic Information Systems (GIS). Monte Carlo simulation was used to generate a range of model results and a GHG analysis of FW collection is used to compare systems of two different AD capacities. The results of this analysis show that food waste is ideal for recycling at relatively small spatial scales as hauling burden of FW is reduced in these systems. The proposed infrastructure modeling approach is a first step of developing a zero net energy infrastructural solution that promotes a circular economy of food in direct response to SB 1383 and, more broadly, global climate change.

Oyster reefs are a primary source of calcium carbonate in most estuaries and the habitat complexity provided by these reefs supports a diversity of estuarine life. The available surface area of hard substrate on an oyster reef is critical for population maintenance, as this substrate provides habitat for the settlement of new oyster recruits. On natural reefs, the primary substrates available for settlement by spat include live oysters, boxes (dead articulated valves), and cultch (single oyster shells and shell fragments). Data from a long-term oyster monitoring program from February 2016 to October 2020 were used to generate a monthly time series of the percent of total carbonate weight contributed by live oysters, boxes, and cultch at four reefs in the Mississippi Sound. These percentages vary spatially and temporally. When reefs were healthy, live oysters dominated the total carbonate. During the study period, two mass mortality events occurred. Following the 2016 mortality event, the substrate contributing the majority of the carbonate shifted from live oysters to cultch at all reefs sampled. Three reefs exhibited a modest population recovery following the mortality event only to be impacted by a second, more severe mass mortality event in 2019. Boxes usually had the highest number of spat per gram carbonate at all reefs. The potential surface area (PSA) of each substrate type was calculated by comparing the available surface area of each substrate type and the number of spat that settled on each substrate. Correction factors were generated to account for larval settlement preferences and used to either debit or credit the PSA to calculate effective surface areas (ESA) for each substrate type. Cultch offered the highest ESA at Pass Christian, and cultch ESA was higher than box ESA at Henderson Point and Between Bridges reefs. At Bay St. Louis, box ESA was twice that of cultch. These results suggest cultch and boxes are more valuable settlement substrates than live oysters in this region under the conditions present during the survey time frame, which was characterized by low oyster abundance and aperiodic mass mortality. The unbalanced ESA, in which live oyster ESA is underrepresented, represents an unhealthy condition and demonstrates that a critical period exists for reef recovery after mass mortality in which the timely coincidence of increased box ESA and larval availability is essential for rapid recovery from mass mortality. KEY WORDS: Crassostrea, effective surface area, oyster reef, recruitment, mass mortality, population dynamics, recovery, INTRODUCTION The desperate state of the eastern oyster (Crassostrea virginica) over much of its US East- and Gulf-coast range, the accompanying loss of reefal area, and the responding investment into [...]

Interest in animal cell-based meat (ACBM) or laboratory-grown meat has been increasing; however, the economic viability of these potential products has not been thoroughly vetted. Recent studies suggest monoclonal antibody production technology can be adapted for the industrialization of ACBM production. This study provides a scenario-based assessment of the projected cost per kilogram of ACBM produced in the United States based on cellular metabolic requirements and process/chemical engineering conventions. A sensitivity analysis of the model identified the nine most influential cost factors for ACBM production out of 67 initial parameters. The results indicate that technological performance will need to approach technical limits for ACBM to achieve profitably as a commodity. However, the model also suggests that low-volume high-value specialty products could be viable based on current technology.

Interest in animal cell-based meat (ACBM) or laboratory-grown meat has been increasing; however, the economic viability of these potential products has not been thoroughly vetted. Recent studies suggest monoclonal antibody production technology can be adapted for the industrialization of ACBM production. This study provides a scenario-based assessment of the projected cost per kilogram of ACBM produced in the United States based on cellular metabolic requirements and process/chemical engineering conventions. A sensitivity analysis of the model identified the nine most influential cost factors for ACBM production out of 67 initial parameters. The results indicate that technological performance will need to approach technical limits for ACBM to achieve profitably as a commodity. However, the model also suggests that low-volume high-value specialty products could be viable based on current technology.

BackgroundDietary patterns affect both human health and environmental sustainability. Prior research found a ten-unit course on food systems and environmental sustainability shifted dietary intake and reduced dietary carbon footprint among college students. This research evaluated the impact of a similar, more scalable one-unit Foodprint seminar taught at multiple universities.MethodsWe used a quasi-experimental pre-post nonequivalent comparison group design (n = 176). As part of the Menus of Change University Research Collaborative, research was conducted at three university campuses in California over four academic terms. All campuses used the same curriculum, which incorporates academic readings, group discussions, and skills-based exercises to evaluate the environmental footprint of different foods. The comparison group comprised students taking unrelated one-unit courses at the same universities. A questionnaire was administered at the beginning and end of each term.ResultsStudents who took the Foodprint seminar significantly improved their reported vegetable intake by 4.7 weekly servings relative to the comparison group. They also reported significantly decreasing intake of ruminant meat and sugar-sweetened beverages. As a result of dietary shifts, Foodprint seminar students were estimated to have significantly decreased their dietary carbon footprint by 14%.ConclusionsA scalable, one-unit Foodprint seminar may simultaneously promote environmental sustainability and human health.

Pinene is a secondary plant metabolite that has functional properties as a flavor additive as well as potential cognitive health benefits. Although pinene is present in low concentrations in several plants, it is possible to engineer microorganisms to produce pinene. However, feedstock cost is currently limiting the industrial scale-up of microbial pinene production. One potential solution is to leverage waste streams such as whey permeate as an alternative to expensive feedstocks. Whey permeate is a sterile-filtered dairy effluent that contains 4.5% weight/weight lactose, and it must be processed or disposed of due its high biochemical oxygen demand, often at significant cost to the producer. Approximately 180 million m3 of whey is produced annually in the U.S., and only half of this quantity receives additional processing for the recovery of lactose. Given that organisms such as recombinant Escherichia coli grow on untreated whey permeate, there is an opportunity for dairy producers to microbially produce pinene and reduce the biological oxygen demand of whey permeate via microbial lactose consumption. The process would convert a waste stream into a valuable coproduct. This review examines the current approaches for microbial pinene production, and the suitability of whey permeate as a medium for microbial pinene production.

Populations of the eastern oyster (Crassostrea virginica) have experienced declines from overfishing and disease throughout much of its US range, though development of maximum sustainable yield (MSY) management criteria has been elusive. This is due in part to the discordance between oyster spawning stock and recruits, as the classic stock- recruitment model does not account for the requirement of shell substrate on which recruits settle. This issue was recently addressed with the development of a surface area-recruitment model, which is herein incorporated into a simulation analysis to estimate MSY-based reference points for C. virginica in the Delaware Bay. Simulations demonstrate that at low natural mortality, fishing mortality (F) may be sustainable at values between 10% and 15%; however, if disease or other mortality-enhancing processes occur, the margin of error in fishing is small and may quickly lead to population and reef collapse, emphasizing a precautionary F < 10%. The MSY-based reference points generated here provide rebuilding goals for the oyster fishery and reef management on fished and unfished reefs and the framework from which shell-planting can be incorporated and optimized in the future. Si les populations d'hurtres americaines (Crassostrea virginica) ont connu des declins dus a la surpeche et aux maladies dans la majeure partie de l'aire de repartition americaine de l'espece, l'elaboration de criteres de gestion bases sur le rendement equilibre maximal (REM) demeure problematique. Cela est du en partie a la discordance entre le stock reproducteur d'hurtres et les recrues, le modele stock-recrutement classique ne tenant pas compte de l'exigence d'un substrat de coquilles pour l'etablissement des recrues. L'elaboration recente d'un modele reliant la superficie au recrutement tente de resoudre ce probleme, et nous integrons ce modele a une analyse de simulation pour estimer des points de reference bases sur le REM pour C. virginica dans la baie du Delaware. Les simulations demontrent que, quand la mortalite naturelle est faible, la mortalite par peche (F) peut etre durable a des valeurs entre 10% et 15%, mais que si des maladies ou d'autres processus qui rehaussent la mortalite ont cours, la marge d'erreur associee a la peche est faible et pourrait rapidement mener a l'effondrement de la population et des recifs, d'ou l'importance, pour une approche prudente, de valeurs de F < 10%. Les points de reference bases sur le REM issus de la presente etude offrent des objectifs de reconstitution pour la peche a l'hurtre et la gestion des recifs exploites et non exploites, ainsi qu'un cadre a partir duquel le depot de coquilles peut etre incorpore et optimise. [Traduit par la Redaction], Introduction The use of biological reference points for sustainable management of commercial fisheries is well ensconced in the management of US federal fisheries, wherein achieving maximum sustainable yield (MSY) is [...]

It has been estimated that one-third of global food is lost or wasted, entailing significant environmental, economic, and social costs. The scale and impact of food loss and waste (FLW) has attracted significant interest across sectors, leading to a relatively recent proliferation of publications. This article synthesizes existing knowledge in the literature with a focus on FLW measurement, drivers, and solutions. We apply the widely adopted DPSIR (Driver-Pressure-State-Impact-Response) framework to structure the review. Key takeaways include the following: Existing definitions of FLW are inconsistent and incomplete, significant data gaps remain (by food type, stage of supply chain, and region, especially for developing countries), FLW solutions focus more on proximate causes rather than larger systemic drivers, and effective responses to FLW will require complementary approaches and robust evaluation.

A sustainable fisheries model for the estimation of harvests of oysters, maintenance of cultch, and restoration of reefs has been applied across the northern Gulf of Mexico. Oyster density and size, and cultch density are provided from surveys by State agencies. The model simulates oyster growth and mortality, and cultch loss. Reef shell mass is increased when oysters die in place and diminished when oysters are removed by fishing. Harvest is estimated as sacks of live oysters that can be removed while retaining reef quality (i.e., reef cultch mass, oyster density). Application of oyster density and cultch density standards (OCS) for fishing at maximum sustained yield shows little sustainable harvest on Public Grounds in the northern Gulf of Mexico. Model heuristics focus discovery of negative and positive feedbacks to reef demise or persistence. Oyster reef dynamics are viewed as persistent processes within negative and positive feedback loops, and occasional shifts between them. A negative feedback loop is set up on poor-quality reefs. Lack of cultch and a paucity of adult oysters diminish recruitment and shell replenishment. In the absence of recruitment, natural shell loss ultimately drives the reef to extinction. A positive feedback loop is set up on reefs with adequate cultch and an abundance of oysters. There, oysters set. survive critical early stages in boxes and reef interstices, reproduce, grow to a large size, and die in place. Harvests on high-quality reefs beyond that which maintains reef cultch and spawning stock, and consequential recruitment failure cause a shift from a positive to a negative feedback loop. Likewise, restricting harvests and planting cultch on poor-quality reefs, together with successful recruitment, promotes a shift from a negative to a positive state. Results of no-net loss of cultch (NNL) and OCS simulations suggest two distinct management approaches. The NNL promotes the sustainability of reef shell and assumes that a stable shell bed promotes a stable living resource, whereas OCS explicitly promotes the sustainability of cultch and stock at msy (maximum-sustainable-yield). Furthermore, OCS, which incorporates optimal reef cultch and oyster density standards, provides restoration benchmarks. Achieving sustainability at msy will simultaneously promote habitat restoration, restoration of ecosystem services, and a sustainable oyster fishery. KEY WORDS: Crassostrea virginica, maximum sustainable yield, reference points, cultch management, fishery management, eastern oyster, INTRODUCTION The eastern oyster Crassostrea virginica, is responsible for creating one of the primary habitat types in the estuaries of the northern Gulf of Mexico. The animal supports a commercial [...]

Ocean quahogs (Arctica islandica) are the longest lived bivalve on Earth. Individuals on the deep continental shelf off Georges Bank can survive for centuries, and in the colder, boreal waters of Iceland, ages over 500 y can be reached. Ocean quahog landings in the United States represent a $24 million industry, yet assessment models operate with no age data because of the substantial sample size required to develop adequate population age distributions for such a long-lived species, the unknown error associated with age estimates, and the extensive time and financial investment required to create production-scale age datasets. Inclusion of age data for this species requires precision metrics to evaluate aging uncertainty such as percent agreement, percent error, coefficient of variation, and tests of bias. To move forward using error-validated age-composition data, a 3-fold error protocol was developed using a large dual-reader dataset (n = 610) from Georges Bank. First, a proxy age-validation study was performed to corroborate an aging method, followed by error evaluation in the context of age-reader bias, precision, and error frequency. Error thresholds were established for each of the three error methods. Georges Bank samples ranged from 33 to 261 y of age and met the predetermined error thresholds for bias (conditionally because of significant and nonsignificant results), precision (average coefficient of variation less than 7%), and error frequency (less than 10%). Consequently, age estimates were deemed acceptable to support age frequency analyses. Precision and bias error were greatest for the youngest animals and, in the context of age-reader bias, error rates were higher for young male ocean quahogs than for young females. Improved age validation of young, sex-differentiated A. islandica will constrain aging error and guide refinement of both aging and age-error protocols. KEY WORDS: ocean quahog, Aretha islandica, error, precision, bias, age-reader, INTRODUCTION Calcified structures (e.g., fish otoliths, vertebrae, coral skeletons. and bivalve shells) are commonly used to age animals in the marine realm (Hudson 1981, Pentilla & Dery 1988, Richardson 2001). [...]

The aims of this study were to identify thermophilic microbial communities that degrade green waste in the presence of the ionic liquids (IL) tetrabutylphosphonium chloride and tributylethylphosphonium diethylphosphate and examine preservation methods for IL-tolerant communities. High-solids incubations with stepwise increases in IL concentration were conducted to enrich for thermophilic IL-tolerant communities that decomposed green waste. 16S rRNA sequencing of enriched communities revealed microorganisms capable of tolerating high levels of IL. Cryogenic preservation of enriched communities reduced the IL tolerance of the community and decreased the relative abundance of IL-tolerant organisms. The use of cryoprotectants did not have an effect on microbial activity on green waste of the stored community. A successful approach was developed to enrich communities that decompose green waste in thermophilic high-solids environments in the presence of IL. Alternative community storage and revival methods are necessary for maintenance and recovery of IL-tolerant communities. The enriched communities provide a targeted source of enzymes for the bioconversion of IL-pretreated green waste for conversion to biofuels.

Stock-recruitment relationships (SRR) are used by many resource managers as a metric to evaluate stock reproductive potential and rebuilding capacity when harvested. This relationship is more evident in traditional finfish stock assessment models where larvae are frequently limited by the abundance of spawning adults, whereas invertebrate resources are much more confounding and often do not express a clear spawning SRR. Oysters in particular appear to be limited more strongly by post-settlement mortality as larvae are regularly demonstrated to be present in high abundance in response to timely shell plants; yet unexpectedly, a brood SRR appears to be present. Because of the unique life history of oysters which provide their own habitat through reef accretion, a posit is that the quantity and quality of such habitat are crucial determinants of recruitment to the stock, and habitat quality acts as a surrogate for brood stock in the stock-recruit relationship. An extensive dataset from Delaware Bay with a 65-y time series was analyzed to assess the relationship between available Crassostrea virginica natural reef materials and subsequent spat ( KEY WORDS: Crassostrea virginica, stock-recruitment relationship, shell surface area, salinity, Delaware Bay. substrate preference, INTRODUCTION Stock-recruitment relationships (SRR) are pivotal parameters used in most modern fishery assessments to estimate stock resiliency (Ricker 1954, Beverton & Holt 1957, Paulik 1973, Ricker 1975, Hilborn & Walters [...]

A mass mortality event that occurred in the Mississippi Sound in September 2016 provided an opportunity for the first natural field study of the rate of taphonomic loss of oyster shell. At the Pass Christian Reef, limited recruitment in the years following the mortality event resulted in little shell addition over a 2.67-y period, thereby permitting a direct comparison between shell present as living oysters in August 2016 and dead shell collected in April/May 2019. By April 2019, most oyster shell valves were riddled with holes, some of which perforated the valves. Deterioration of the shell surface was ubiquitous, and edge erosion was commonplace. Left valves were preferentially preserved: the left valves comprised 67% of the intact valves and 85% of the minor fragments after 2.67 y. Thus, at the time of collection, minimally 50% of the right valves originally present on the reef had disappeared. The increased differential between left and right valves of the minor fragments suggests a continuing differential in preservation, leading to cultch being overwhelmingly represented by left valves. Based on estimates derived from changes in shell weight at length and estimates of right-valve loss, by April 2019, between 30% and 51% of the carbonate originally added to the reef in 2016 was lost, yielding an estimated oyster shell half-life of between 2.6 and 5.1 y in the Mississippi Sound. The half-lives estimated from this first infield experiment fall precisely within the range of previous less direct estimates from laboratory experiments or survey time series. Oyster shell degrades rapidly: case histories now include a wide latitudinal range and a wide temperature range, which suggests that these rapid shell degradation rates are the norm over most of the range of the eastern oyster. Understanding the impermanence of oyster shell is crucial to the sustainable management of oyster reefs, as the addition of shell to the reef framework must balance rapid shell degradation rates to prevent stock collapse and ultimately the loss of reef structure. KEY WORDS: taphonomy, shell loss, Crassostrea virginica, Mississippi Sound, INTRODUCTION Carbonate input by bivalve shell formation into marine and estuarine sediments is quantitatively comparable to the production of wood by trees in a forest (Gutierrez et al. 2003). Sedimentary [...]

ABSTRACT Ocean quahogs [Arctica islandica (Linnaeus, 1769)] are the longest-lived, noncolonial animal known today, with a maximum life span exceeding 500 y. Ocean quahogs are a commercially important bivalve, inhabiting [...]

Abstract Voice recognition technologies (VRT) are learning technologies that enhance students' composing processes. They encourage instructors to ask questions concerning what benefits oral composing can bring. This essay reviews several [...]

Abstract Given that scholarship dealing with feminism in the technology based first year composition classroom is sparse, it is crucial to examine how well we as feminist instructors can fit [...]