Distinct Water Bodies Research Articles

Microbiomes on microplastics versus natural microcarriers: Stability and transformation during aquatic travel from aquaculture ponds to adjacent stream

Microplastics (MPs) with different physical-chemical properties are considered as vectors for the propagation of microbes in aquatic environments. It remains unclear how plastic types impact on the plastisphere and whether different MPs spread microbes more rapidly than natural materials in microbes across distinct water bodies as proposed previously. We used in-situ incubation to investigate the microbes attached on MPs of polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC), versus that on two natural microcarriers (quartz sands and bamboo) during the travel from aquaculture ponds with impacted by fish farming to adjacent freshwater stream. The results showed that the microbial communities on the carriers were shaped not only by environmental conditions, which were primary determinants but also by carrier types. All the tested plastics did not carry more microbes than the natural carriers during the journey. The biofilm community composition on PVC is distinct from that on PE and PP MPs and natural carriers. The plastisphere of PE and PP kept microbial proportions as natural materials did but PVC retained less than nature materials. Bamboo carried more potential pathogens than plastic polymers and quartz. The results indicated that the communities of plastisphere is polymer-type dependent, and, compared with the natural materials, MPs did not show enhanced propagation of microbes, including pathogens, cross distinct environments.

The use of the self-organizing map (SOM) methodology to study the dissolved organic matter (DOM) in different water body types.

This study investigated the characteristics of dissolved organic matter (DOM) in two distinct water bodies, through the utilization of three-dimensional fluorescence spectroscopy coupled with self-organizing map (SOM) methodology. Specifically, this analysis concentrated on neurons 3, 14, and 17 within the SOM model, identifying notable differences in the DOM compositions of a coal subsidence water body (TX) and the MaChang Reservoir (MC). The humic substance content of DOM TX exceeded that of MC. The origin of DOM in TX was primarily linked to agricultural inputs and rainfall runoff, whereas the DOM in MC was associated with human activities, displaying distinctive autochthonous features and heightened biological activity. Principal component analysis revealed that humic substances dominated the DOM in TX, while the natural DOM in MC was primarily autochthonous. Furthermore, a multiple linear regression model (MLR) determined that external pollution was responsible for 99.11% of variation in the humification index (HIX) of water bodies.

Variations in the Odonata Assemblages: How Do the Dry Season and Water Bodies Influence Them?

Diverse abiotic and biotic factors drive the ecological variation of communities across spatial and temporal dimensions. Within the Amazonian landscape, various freshwater environments exhibit distinct physicochemical characteristics. Thus, our study delved into the fluctuations of Odonata assemblages amidst distinct water bodies within Amazonia, encompassing two distinct climatic seasons. Comparative analysis was conducted on Odonata species diversity and assemblage composition across a blackwater pond, a lake, and a stream, spanning the initiation and culmination of the dry season in the southwestern Amazon region in Peru. Our methodology involved capturing adult Odonata using entomological nets on three separate occasions between 11:00 and 14:00h for each water body in May (beginning of the dry season) and October (end of the dry season) of 2018. We also evaluated the influence of temperature, precipitation, and percent cloud cover on the abundance and richness of adult Odonata. Species richness and composition differed among the three water bodies in both periods of the dry season. No effect of the dry season periods on species richness and abundance was observed. However, except in the oxbow lake, the more abundant species were substituted to the end of the dry season. Our study highlights the influence of water body types on Odonata species diversity and composition. The effects of the sampling period during the dry season may not be immediately apparent in conventional diversity metrics, such as species richness and abundance. Instead, its effects manifest predominantly in the relative abundance of the species that compose these assemblages.

Characteristics of Groundwater Microbial Community Composition and Environmental Response in the Yimuquan Aquifer, North China Plain

To explore the intricate interrelationship between groundwater microbial communities and hydrochemical characteristics in the Mancheng District, Baoding City, samples from karst groundwater and porous groundwater were collected. Hydrochemical analysis and the 16s RNA gene V4-V5 region sequencing method were used to detail the water environmental characteristics and microbial community distribution pattern in the study area. The hydrochemical results reveal notable differences in major ion contents and other hydrochemical indices between karst water and porous water. Microbial community analysis demonstrates that Proteobacteria, Actinobacteria, and Firmicutes are the dominant taxa in both types of water bodies, albeit with significant variations in their proportions across distinct water bodies. The observed disparities in microbial communities between karst water and porous water underscore the influence of environmental factors such as ion concentration and pH on microbial distribution. Redundancy Analysis (RDA) indicates notable associations between microbial community composition and environmental factors in both types of groundwater environments. Studying the distribution pattern of microbial communities and the connection with environmental factors in two types of groundwater lays a crucial foundation for interpreting the functional roles of microbes in groundwater ecosystems.

Data-driven modelling for assessing trophic status in marine ecosystems using machine learning approaches

Assessing eutrophication in coastal and transitional waters is of utmost importance, yet existing Trophic Status Index (TSI) models face challenges like multicollinearity, data redundancy, inappropriate aggregation methods, and complex classification schemes. To tackle these issues, we developed a novel tool that harnesses machine learning (ML) and artificial intelligence (AI), enhancing the reliability and accuracy of trophic status assessments. Our research introduces an improved data-driven methodology specifically tailored for transitional and coastal (TrC) waters, with a focus on Cork Harbour, Ireland, as a case study.Our innovative approach, named the Assessment Trophic Status Index (ATSI) model, comprises three main components: the selection of pertinent water quality indicators, the computation of ATSI scores, and the implementation of a new classification scheme. To optimize input data and minimize redundancy, we employed ML techniques, including advanced deep learning methods. Specifically, we developed a CHL prediction model utilizing ten algorithms, among which XGBoost demonstrated exceptional performance, showcasing minimal errors during both training (RMSE = 0.0, MSE = 0.0, MAE = 0.01) and testing (RMSE = 0.0, MSE = 0.0, MAE = 0.01) phases.Utilizing a novel linear rescaling interpolation function, we calculated ATSI scores and evaluated the model's sensitivity and efficiency across diverse application domains, employing metrics such as R2, the Nash-Sutcliffe efficiency (NSE), and the model efficiency factor (MEF). The results consistently revealed heightened sensitivity and efficiency across all application domains. Additionally, we introduced a brand new classification scheme for ranking the trophic status of transitional and coastal waters. To assess spatial sensitivity, we applied the ATSI model to four distinct waterbodies in Ireland, comparing trophic assessment outcomes with the Assessment of Trophic Status of Estuaries and Bays in Ireland (ATSEBI) System. Remarkably, significant disparities between the ATSI and ATSEBI System were evident in all domains, except for Mulroy Bay.Overall, our research significantly enhances the accuracy of trophic status assessments in marine ecosystems. The ATSI model, combined with cutting-edge ML techniques and our new classification scheme, represents a promising avenue for evaluating and monitoring trophic conditions in TrC waters. The study also demonstrated the effectiveness of ATSI in assessing trophic status across various waterbodies, including lakes, rivers, and more. These findings make substantial contributions to the field of marine ecosystem management and conservation.

The landscape of nature-derived antimalarials-potential of marine natural products in countering the evolving Plasmodium

Malaria poses several challenges to the global research community on both diagnostic and therapeutic fronts. Most prominent of them are deletion of target genes (pfhrp2/3) used in rapid diagnostic tests (RDTs) and the emergence of resistance against frontline antimalarials by the evolving parasite. Exploration of novel therapeutics for malaria in view of limited vaccine options is a promising resort for malaria control and elimination. The scope of marine-derived chemotherapeutics is exciting, with a significant number of FDA-approved drugs or therapeutic leads under clinical trials for other diseases. This review article discusses the significant antimalarial potential of marine-derived natural products extracted from diverse biota including sponges, bacteria, sea hare and algae etc. Bioassay-guided fractionation of raw extracts from marine organisms for lead identification and further structural characterization of purified compounds compose a sustainable marine-derived drug discovery pipeline; which can be particularly diverted towards the exploration of antimalarials. It is to be noted that the Indian peninsula is largely unexplored, particularly for antimalarials screening; which has a huge marine biodiversity owing to the three distinct water bodies- Bay of Bengal, Indian Ocean and Arabian sea. This review also envisions a collaborative initiative to explore the potential of marine natural products in an economically feasible manner.

Mars Science Laboratory CheMin Data From the Glen Torridon Region and the Significance of Lake‐Groundwater Interactions in Interpreting Mineralogy and Sedimentary History

AbstractThe Glen Torridon (GT) region in Gale crater, Mars is a region with strong clay mineral signatures inferred from orbital spectroscopy. The CheMin X‐ray diffraction (XRD) instrument onboard the Mars Science Laboratory rover, Curiosity, measured some of the highest clay mineral abundances to date within GT, complementing the orbital detections. GT may also be unique because in the XRD patterns of some samples, CheMin identified new phases, including: (a) Fe‐carbonates, and (b) a phase with a novel peak at 9.2 Å. Fe‐carbonates have been previously suggested from other instruments onboard, but this is the first definitive reporting by CheMin of Fe‐carbonate. This new phase with a 9.2 Å reflection has never been observed in Gale crater and may be a new mineral for Mars, but discrete identification still remains enigmatic because no single phase on Earth is able to account for all of the GT mineralogical, geochemical, and sedimentological constraints. Here, we modeled XRD profiles and propose an interstratified clay mineral, specifically greenalite‐minnesotaite, as a reasonable candidate. The coexistence of Fe‐carbonate and Fe‐rich clay minerals in the GT samples supports a conceptual model of a lacustrine groundwater mixing environment. Groundwater interaction with percolating lake waters in the sediments is common in terrestrial lacustrine settings, and the diffusion of two distinct water bodies within the subsurface can create a geochemical gradient and unique mineral front in the sediments. Ultimately, the proximity to this mixing zone may have controlled the secondary minerals preserved in sedimentary rocks exposed in GT.

Genetic Differentiation and Molecular Phylogenetics of North African Catfish from Three Distinct Waterbodies

Abstract The population structure and genetic variability of North African catfish Clarias gariepinus (Burchell 1822) were investigated using partial mitochondrial DNA cytochrome b region sequences. Fifty-four (54) samples were investigated from three geographically isolated rivers in Nigeria. The analysis of 53 haplotypes revealed greater haplotype diversity (0.99930) and nucleotide diversity (p) (0.07270). According to an analysis of molecular variance (AMOVA), the genetic diversity of North African catfish within populations is significantly higher than the genetic diversity across populations. The FST scores (0.75000, 0.94792 and 0.95699) indicated that North African catfish populations in three Nigerian freshwater bodies had a strong genetic structure. The phylogenetic reconstruction of unique haplotypes revealed the placement of a haplotype (Ogbese) linked by others from all three groups with a point mutation ranging from 1 to 24 nucleotides. North African catfish populations in the Asejire and Ureje are genetically diverse, as evidenced by a high level of haplotype diversity of 1.0000, low nucleotide diversity spanning from 0.05101 to 0.07889, and high FST values (within-population genetic variation). The common haplotypes between some populations and mixes of haplotypes from different populations within the same genetic cluster demonstrate that the population genetic structure is not distinct.

A Study on Traditional Fishing Gears and Fish Capturing Methods Used by The Mising Community of Gohpur Subdivision, Biswanath District, Assam

The implementation of various fishing hing gears is the product of experiences gathered over the course of a significant amount of time. Every water body has its own particular arrangement of gears. The use of fishing equipment also provides insight on the community of fishermen's financial situation. In order to produce substances of technological delight while keeping costs to a minimum, fishermen employ materialmaterials that are readily available in their local area. A research was carried out on the fishermen in the Mising subdivision of the Gohpur district in order to collect data on the various traditional fishing gears and methods of catching fish. It has been discovered vered that Mising fisherman employ a variety of fishing gear, the majority of which they designed on their own. Different fishing gear is utilized during different times of the year and in distinct bodies of water for catching fish of varying sizes. In addition to their participation in community fishing, Mising women also participate in fishing on their own. They fish for enjoyment in addition to commercial reasons. Total 28 types of gears and different methods of fish capturing have have been reported during the survey period. All gears ar are eco-friendly. To raise awareness among fishermen of the long-term effects of their fishing techniques, workshops or training programmes should be organised.

Phytoplankton dynamics in a drinking water catchment zone at the Amazon River mouth

Phytoplankton is formed by photosynthesizing microorganisms that act as primary producers in distinct water bodies. These include microalgae and cyanobacteria. It is essential to know the phytoplankton in water catchment areas intended for drinking water treatment once their excessive density may result in problems, such as taste and odor in the water, toxin production, filter clogging, and other damages. This study investigated the phytoplankton dynamics and the environmental factors that may influence phytoplankton density in the drinking water catchment zone of Macapá, a city located on the Amazon River mouth. The sampling was carried out monthly from April/2015 to March/2016. The study reports the first detailed information on the phytoplankton in the study area since previously published studies regarded only cyanobacteria. The species Limnothrix planctonica and Aulacoseira granulata may substantially influence the water treatment due to their great abundance in the study area, especially in July and November, when their density peaks occur, respectively. Nevertheless, Aulacoseira granulata is the primary constituent of the phytoplankton biovolume. This study provides biological and sanitary information to guide public administration towards improving the quality and safety of water supply services, and also to increase the biodiversity knowledge of Amazonian phytoplankton.

Historic low stand of Great Salt Lake, Utah: I

Great Salt Lake of Utah is among the largest and most ecologically important water bodies in North America. Since the late 1950s, the lake has been divided into two hydrologically distinct water bodies by a rock-fill railroad causeway. Flux through the causeway is driven by two forces: differential surface elevation and differential density between the north and south arms. The south arm features episodic vertical stratification due to the influx of deep, dense brine from the north arm. The source of this brine (a breach, two culverts, or subsurface flow) has been investigated over the past 50 years. Quantification of subsurface water flux through the causeway has been problematic due to the heterogeneous and slowly compacting nature of the causeway fill over time. Between 2008 and 2015, enhanced gauging of various surface inflows and outflows and density measurements made throughout the lake permitted detailed water volume calculations of both lake arms. Results show that during high precipitation years, density-driven, north-to-south flow through the causeway predominates due to freshening of water in the south arm. At other times, south-to-north head gradient driven flow and north-to-south density-driven flow are approximately equal. The model suggests subsurface flux through the causeway is one important driver of the ecologically important deep brine layer in the south arm of the lake over the past 20 years.

Comparing fish prey diversity for a critically endangered aquatic mammal in a reserve and the wild using eDNA metabarcoding

Using environmental DNA (eDNA) metabarcoding, we compared fish diversity in two distinct water bodies within the Yangtze River Basin with known populations of the critically endangered Yangtze finless porpoise (Neophocaena asiaeorientalis; YFP): the Tian-e-Zhou Reserve and Poyang Lake. We aimed to create a fish surveying tool for use in the Yangtze River Basin, while also gaining a better understanding of the prey distribution and diversity within two of the remaining strongholds of YFP. 16S rRNA universal primers were developed to amplify fish eDNA. After high-throughput sequencing and stringent data filtering, we identified a total of 75 fish species (6 orders, 9 families, 57 genera) across seasons and regions. Nine of the 75 fish species were among the 28 known YFP prey species, three of which were detected in all water samples. Our eDNA metabarcoding identified many species that had been previously captured using traditional netting practices, but also numerous species not previously collected in these water bodies. Fish diversity was higher in Poyang Lake than in Tian-e-Zhou Reserve, as well as higher in the spring than in summer. These methods provide a broadly applicable tool to quantify fish diversity and distributions throughout the Yangtze River Basin, and to inform conservation strategies of YFP.

A Method for Chlorophyll-a and Suspended Solids Prediction through Remote Sensing and Machine Learning.

Total Suspended Solids (TSS) and chlorophyll-a concentration are two critical parameters to monitor water quality. Since directly collecting samples for laboratory analysis can be expensive, this paper presents a methodology to estimate this information through remote sensing and Machine Learning (ML) techniques. TSS and chlorophyll-a are optically active components, therefore enabling measurement by remote sensing. Two study cases in distinct water bodies are performed, and those cases use different spatial resolution data from Sentinel-2 spectral images and unmanned aerial vehicles together with laboratory analysis data. In consonance with the methodology, supervised ML algorithms are trained to predict the concentration of TSS and chlorophyll-a. The predictions are evaluated separately in both study areas, where both TSS and chlorophyll-a models achieved R-squared values above 0.8.

A flood of information: Using Sentinel-3 water colour products to assure continuity in the monitoring of water quality trends in the Great Barrier Reef (Australia)

An operational method to assess trends in marine water composition and ecosystem health during flood periods has been developed for the Great Barrier Reef (GBR), Queensland, Australia. This method integrates satellite water colour data with field water quality and ecosystem monitoring data and involves the classification of Moderate-Resolution Imaging Spectroradiometer (MODIS satellite) pixels into six distinct water bodies using a “wet season” colour scale developed specifically for the GBR. Using this information, several monitoring and reporting products have been derived and are operationally implemented into a long-term water quality monitoring program for the GBR. However, MODIS sensors are aging and a long-term monitoring solution is needed. This study reviewed the water colour monitoring products currently used in the GBR. It tested the feasibility to transition these methods from historical MODIS satellite imagery to the new Sentinel-3 satellite of the European Space Agency and from the wet season colour scale to the historical Forel-Ule colour scale, using a freely-distributed Forel Ule (FU) Satellite Toolbox. Monitoring products derived from both satellites and colour scales showed very similar patterns across two case study regions of the GBR, the Wet Tropics and Burdekin marine regions, over the 2017-18 wet season. The results obtained in this study highlighted the potential of using FU Sentinel-3 imagery for the mapping of GBR marine water bodies, including flood conditions. Furthermore, the operational monitoring products and frameworks developed for the GBR are likely to provide valuable foundations for analysis of FU Sentinel-3 data in the future. Such satellite water colour datasets and frameworks will be instrumental to better understand the impact of floods and reduced water clarity on marine ecosystems, as well as to support water quality management and facilitate catchment management policy in the GBR and worldwide.

Characterization of organic contaminants in fjords and bays on the Kenai Peninsula Alaska.

A baseline environmental characterization of Seldovia Bay and harbor on the Kenai Peninsula, Alaska, was conducted using a sediment quality approach. The data was derived from a larger study that assessed seven distinct water bodies on the Kenai Peninsula's north side, draining into Kachemak Bay or into Lower Cook Inlet. Sampling sites for water quality measurements, sediment chemistry, and benthos were randomized within each embayment. Concentrations of 140 organic and elemental contaminants were analyzed. Habitat parameters (depth, salinity, grain size, organic carbon, etc.) that influence species and contaminant distribution were also measured at each sampling site. Concentrations of chlorinated pesticides and PCBs were uniformly low, with the exception of Seldovia Harbor, where total DDT and PCBs exceeded the lower sediment quality guidelines. Concentrations of PAHs were relatively low, except in Seldovia Harbor where concentrations exceeded lower sediment quality guidelines for PAHs, and in one location approached the upper limit. That concentration of PAHs exceeded all other measurements in the NOAA National Status & Trends database for the entire State of Alaska. Characteristics of the PAH compounds present indicate large contributions of pyrogenic sources (burned fuel and/or other organic matter). Seldovia Bay had much lower PAH concentrations than the harbor.

Characterization of metal/metalloid concentrations in fjords and bays on the Kenai Peninsula, Alaska

A baseline environmental characterization of Chrome and Dogfish bays on the Kenai Peninsula, Alaska, was conducted using a sediment quality triad approach. Resident fish and blue mussel body burdens were also assessed. The data was derived from a larger study that assessed seven distinct water bodies on the Kenai Peninsula's north side, draining into Kachemak Bay. Sampling sites for water quality measurements and sediment were randomized within each embayment. Concentrations of 140 organic and elemental contaminants were analyzed. Habitat parameters (depth, salinity, temperature, dissolved oxygen, sediment grain size, and organic carbon content) that influence elemental distribution were also measured at each sampling site. Chrome Bay and Dogfish Bay open into lower Cook Inlet and had coarser sediments than the other bays studied. Concentrations of chromium and nickel were extremely high in Chrome Bay. Concentrations were several times higher than observed concentrations seen throughout other locations in south-central Alaska. Other elemental concentrations varied between and within bays, with several locations exceeding lower sediment quality guidelines. Whole sediment amphipod toxicity bioassays were conducted with sediments from Chrome Bay. No sample exhibited significant mortality or sublethal effects. Body burdens of three species of fish and mussels collected in Chrome Bay did not exhibit elevated concentrations relative to other studies in Kachemak Bay or the Alaska Dept. of Environmental Conservation, Fish Monitoring Program. Despite the very high concentrations of Cr and Ni in the sediments, the metals do not appear to be bioavailable to resident biota.

Diversity of Biomphalaria spp. freshwater snails and associated mollusks in areas with schistosomiasis risk, using molecular and spatial analysis tools

Abstract: The Middle Paranapanema River region of São Paulo, Brazil is home to significant diversity of Biomphalaria species and is very vulnerable to health and environmental impacts such as schistosomiasis. This study updates freshwater malacological surveys for ecosystems in one portion of the Middle Paranapanema River Basin, with emphasis on the genus Biomphalaria. Snails were collected from 114 distinct bodies of water between 2015 and 2018. Biomphalaria specimens were identified according to morphological and molecular characteristics, while animals in other genera (Drepanotrema, Lymnaea, Melanoides, Physa and Pomacea) were identified solely according to shell characteristics. A geographic information system was used to update intermediate host colonization sites and consequently assist in identifying probable hotspots for intermediate hosts of schistosomiasis. The sequences of the COI gene relating to the DNA barcode stretch were tested for similarity against sequences found in GenBank, for monophyly through Maximum Likelihood phylogenetic inference, and analyzed in ABDG, bPTP and GMYC for the delimitation of putative species. Of the 10,722 snails collected, 86.7% were in the Planorbidae family (75.5% Biomphalaria and 11.2% Drepanotrema) and 13.3% were other non-Planorbidae species (Lymnaea, Melanoides, Physa and Pomacea). The taxonomic COI reference sequences in the NCBI nucleotide database used for DNA sequence comparison, and phylogenetic analysis used to test the monophyly of the groups, resulted in more reliable taxonomic units than delimitation of the COI sequences in MOTUs using statistical taxonomic models. Analysis of the species distribution shows that B. glabrata and B. tenagophila are heterogeneously distributed in the study area. B. glabrata colonizes only five water bodies, in the study area, most of them in Ourinhos, while B. tenagophila predominates in water bodies in Ipaussu. Contrasting with this, B. straminea, B. occidentalis and B. peregrina are evenly distributed throughout the study area.

Effect of photo-biodegradation and biodegradation on the biogeochemical cycling of dissolved organic matter across diverse surface water bodies.

The objective of this research was to quantify the temporal variation of dissolved organic matter (DOM) in five distinct waterbodies in watersheds with diverse types of land use and land cover in the presence and absence of sunlight. The water bodies were an agricultural pond, a lake in a forested watershed, a man-made reservoir, an estuary, and a bay. Two sets of samples were prepared by dispensing unfiltered samples into filtered samples in 1:10 ratio (V/V). The first set was exposed to sunlight (10 hr per day for 30 days) for examining the combined effect of photo-biodegradation, while the second set was stored in dark for examining biodegradation alone. Spectroscopic measurements in tandem with multivariate statistics were used to interpret DOM lability and composition. The results suggest that the agricultural pond behaved differently compared to other study locations during degradation experiments due to the presence of higher amount of microbial humic-like and protein-like components derived from microbial/anthropogenic sources. For all samples, a larger decrease in dissolved organic carbon (DOC) concentration (10.12% ± 9.81% for photo-biodegradation and 6.65% ± 2.83% for biodegradation) and rapid transformation of DOM components (i.e., terrestrial humic-like components into microbial humic and protein-like components) were observed during photo-biodegradation experiments. Results suggest that sunlight facilitated DOM biodegradation, resulting in simpler recalcitrant molecules regardless of original composition. Overall, it was found that combined effects of light and bacteria are more efficient than bacterial effects alone in remineralizing and altering DOM, which highlights the crucial importance of sunlight in transforming aquatic DOM.

Effects of climate variability on freshwater fisheries in Cambodia's rice field fisheries: a longitudinal cohort study

BackgroundProjections suggest that by 2050, climate change will reduce global fish catch by 3–13%, with fish catch falling by as much as 30% in some tropical marine systems. Freshwater fisheries are particularly susceptible to the warming effects of climate change because shallower, hydrologically distinct water bodies are easily affected by atmospheric temperatures and less easily accommodate fish migrations. Damage to freshwater fisheries is a problem particularly for poor and undernourished human populations, which are especially dependent on them. Despite the severity of projected climate change effects on fish catch and the risk to human health, few empirical studies have examined how fish catch is already responding to climate variability, the ways fishers are adapting to these changes, and how it affects people's consumption of fish, which are rich in micronutrients and fatty acids. We aim here to account for behavioural responses among fishers to identify the ecological effect of flood and weather on fish catch in Cambodian rice field fisheries, and patterns of fish consumption and nutrition in the local communities. MethodsIn this longitudinal cohort study, we use a panel dataset collected by WorldFish of 400 households dependent on rice field fisheries over 3 years (19 distinct timepoints) to examine how changing flood patterns and temperature alter households' fish catch and whether fishing families respond by either adapting the effort put into fishing (ie, hours, time of day, or number of family members involved) or fish consumption. We analyse the net effect of biophysical changes on household fish catch, the effect of biophysical changes (flood, temperature, and rainfall) on household fish catch and fish consumption with the addition of controls for fishing effort, a key way that fishers might adapt to ecological changes, and the direct effect of biophysical changes on fishing effort and fish consumption. FindingsPreliminary results suggest that from November, 2012, to November, 2015, fishing families changed their fishing effort and practices to adapt to the effects of flood and temperature changes on fish catch. Updated data and analyses will allow us to disentangle these effects by using an identification strategy to separate the ecological effects of flood and temperature changes on fish catch from the ways households respond to changes in fish availability. InterpretationOur results have broad implications for understanding the ways that climate change might affect the 10% of the global population that rely on small-scale fisheries in low-income countries. Analyses of fish catch will show the effects of flood and temperature changes on fish catch and how households respond to these changes. Further, analyses of the effects on consumption of fish will show how temperature potentially alters access to micronutrient-rich food. Our findings suggest the ways that the changing global climate might affect the health and wellbeing of natural resource-dependent communities. FundingFinancial support for this project was provided by the US Agency for International Development (USAID) through the Rice Field Fisheries Enhancement project and Cornell University's David R Atkinson Center for a Sustainable Future Postdoctoral Fellows Program. The contents and opinions expressed herein are those of the authors and do not necessarily reflect the views of USAID or the US Government.

Integration of ecosystem-based models into an existing interactive web-based tool for improved aquaculture decision-making

Proper site selection is critical to the development and expansion of marine aquaculture. Major considerations for site selection include: potential for competing uses, environmental interactions, and animal productivity. Two types of existing site selection tools, mapping and modeling, have proven useful independently, and in some recent studies have proven useful when used together. GIS-based mapping tools have become important in the decision-making process. These tools provide access to marine and coastal datasets allowing farmers and extension agents to gather information on availability of cultivation sites. They are also used by resource managers to assess potential use conflicts (e.g. existence of commercial fishing, mooring areas, fixed fishing gear) and possible environmental interactions (e.g. presence of seagrasses, contaminants, threatened or endangered species). Models have been used separately to predict animal growth, farm productivity, and farm-related effects on the surrounding water and sediment quality.The integration of the Farm Aquaculture Resource Management (FARM) model (http://www.farmscale.org) into the U.S. state of Connecticut's Aquaculture Mapping Atlas (http://seagrant.uconn.edu/whatwedo/aquaculture/shellmap.php) was tested in three geographically distinct waterbodies within Connecticut (CT) waters of Long Island Sound. Nearshore waters within the towns of Mystic, Milford, and Westport were selected as pilot locations to determine usability and capability of the combined tools. Data from two long-term offshore sampling stations adjacent to existing shellfish leases were used to test spatial and temporal sampling variability impacts on model results. Partnerships with local monitoring programs and growers were important for acquisition of water quality data, oyster measurement data, and information about local culture practices. All sites were deemed suitable for oyster aquaculture based on model results that predicted Moderate to High growth based on estimated time to reach harvest size from one in (2.54cm) seed oysters (Crassostrea virginica). Time to harvest varied from 282days (High growth) to 645days (Moderate growth) among the 22 stations in the three nearshore sites, and 724–956days (Moderate growth) at the two offshore sites. Results from the two long-term offshore stations indicate that data from the same year must be used when comparing production-based suitability of sites. Addition of potential production estimates improved the ability to select between suitable mapping-based sites. This mapping and modeling combination should be encouraged to provide a strong basis for successful siting and expansion of aquaculture while minimizing user conflict and adverse environmental interactions. This approach may be particularly useful in waterbodies where shellfish aquaculture is possible but is not well established.