Indian River Research Articles

Broiler welfare is preserved by long-term low-dose oral exposure to zinc oxide nanoparticles: preliminary study

The potential public health risk through utilizing of zinc oxide nanoparticles (ZnO NPs) in food constitutes the major obstacle to the expansion of nanoparticle (NP) in food industry. Liver histology, bone marrow and liver genotoxicity, immunity, and oxidant status were investigated upon long-term ZnO NPs feed supplementation. One hundred and sixty male IR (Indian River) chicks were randomly allocated to one of the four dietary treatments: control, ZnO NPs at 10, 20, or 40 mg/kg for 42 days. This study revealed non-significant hepatic histopathological alterations and DNA damage and the treatment had no influence on body and organ weights, liver enzymes, lipid peroxidation (MDA), IgG, IgM, and interferon gamma (IFN-γ). This study suggests that low-dose (< 40 mg/kg diet) long-term ZnO NPs supplementation to broiler chicks has no observed potential adverse effects on normal histology of the liver, blood physiology, immune system, and DNA damage of liver and bone marrows, which are critical features for validating ZnO NPs for use in food. Further studies are required to evaluate the probable withdrawal period of ZnO NPs before approval as a dietary supplement in broiler or livestock diets.

Silver Nanoparticles as Modulators of Myogenesis-Related Gene Expression in Chicken Embryos.

The present study was conducted to investigate the effects of colloidal nanoparticles of silver (Nano-Ag) on the expression of myogenesis-related genes in chicken embryos. The investigated genes included the members of the myogenic regulatory factors family (MRFs) and myocyte enhancer factor 2A (MEF2A) genes. A total of 200 fertilized broiler eggs (Indian River) were randomly distributed into four groups; non-injected control, injected control with placebo, treatment I in ovo injected with 20 ppm Nano-Ag, and treatment II in ovo injected with 40 ppm Nano-Ag. The eggs were then incubated for 21 days at the optimum temperature and humidity conditions. Breast muscle tissues were collected at the 5th, 8th, and 18th days of the incubation period. The mRNA expression of myogenic determination factor 1 (MYOD1), myogenic factor 5 (MYF5), myogenic factor 6 (MYF6), myogenin (MYOG), and MEF2A was measured at the three sampling points using real-time quantitative PCR, while MYOD1 protein expression was evaluated on day 18 using western blot. Breast muscle tissues were histologically examined on day 18 to detect the changes at the cellular level. Our results indicate that myogenesis was enhanced with the low concentration (20 ppm) of Nano-Ag due to the higher expression of MYOD1, MYF5, and MYF6 at the transcriptional level and MYOD1 at the translational level. Moreover, histological analysis revealed the presence of hyperplasia (31.4% more muscle fibers) in treatment I (injected with 20 ppm). Our findings indicate that in ovo injection of 20 ppm Nano-Ag enhances the development of muscles in chicken embryos compared with the 40-ppm dosage and provide crucial information for the use of silver nanoparticles in poultry production.

Investigation of microplastic pollution in river Alaknanda stretch of Uttarakhand

Microplastic pollution research is conducted at a rapid rate throughout the world. However, microplastics (MPs) research in the freshwater ecosystem especially riverine ecosystem is lacking in India. This study is the pioneer to explore the occurrence of MPs in an Indian river. For the present investigation a stretch of river Alaknanda which is a major stream of river Ganga was selected. This stretch was divided into five sampling sites from which five water samples and four sediment samples were collected. The samples were filtered, oxidized, density separated and finally studied under compound microscope and Scanning Electron Microscope. Further, Energy-Dispersive X-ray Spectrum was also conducted to analyze the elemental status of the samples. The result of this research study recorded a total of 955 MPs. Among which 566 particles of the MPs were in water samples while 389 particles were found in sediment samples. In this study threads/fibers were the dominating type, i.e., 412 particles and particle size less than 1 mm was the most abundant type of MPs. Presence of such fine size of plastic particles increases the effect of exposure and interaction of particles with aquatic organisms and possesses a bigger threat for aquatic life. Metals like sodium, potassium, aluminum, calcium, titanium and magnesium were found attached with the MPs, indicating the potential risks to the living organisms.

Monthly and Seasonal Drought Characterization Using GRACE-Based Groundwater Drought Index and Its Link to Teleconnections across South Indian River Basins

Traditional drought monitoring is based on observed data from both meteorological and hydrological stations. Due to the scarcity of station observation data, it is difficult to obtain accurate drought distribution characteristics, and also tedious to replicate the large-scale information of drought. Thus, Gravity Recovery and Climate Experiment (GRACE) data are utilized in monitoring and characterizing regional droughts where ground station data is limited. In this study, we analyzed and assessed the drought characteristics utilizing the GRACE Groundwater Drought Index (GGDI) over four major river basins in India during the period of 2003–2016. The spatial distribution, temporal evolution of drought, and trend characteristics were analyzed using GGDI. Then, the relationship between GGDI and climate factors were evaluated by the method of wavelet coherence. The results indicate the following points: GRACE’s quantitative results were consistent and robust for drought assessment; out of the four basins, severe drought was noticed in the Cauvery river basin between 2012 and 2015, with severity of −27 and duration of 42 months; other than Godavari river basin, the remaining three basins displayed significant negative trends at monthly and seasonal scales; the wavelet coherence method revealed that climate factors had a substantial effect on GGDI, and the impact of Southern Oscillation Index (SOI) on drought was significantly high, followed by Sea Surface Temperature (SST) Index (namely, NINO3.4) and Multivariate El Niño–Southern Oscillation Index (MEI) in all the basins. This study provides reliable and robust quantitative result of GRACE water storage variations that shares new insights for further drought investigation.

Did the Coronavirus Disease 2019 Lockdown Phase Influence Coastal Water Quality Parameters off Major Indian Cities and River Basins?

The end of the current decade experienced an outbreak of a new strain of coronavirus classified as severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) [coronavirus disease 2019 (COVID-19)] that spread across the globe within a short span of time and was declared as a global pandemic by the World Health Organization. In order to contain the spread of COVID-19, the Indian Government imposed lockdown in various phases, namely, the strict lockdown period (SLP) and relaxed lockdown period (RLP). The present study addresses changes in the magnitude of satellite-derived water quality parameters in the coastal waters off major Indian cities (Mumbai and Chennai) and river basins (Narmada, Mandovi-Zuari, Netravathi, Periyar, Kaveri, Krishna-Godavari, Mahanadi, and Hooghly) along the eastern Arabian Sea (EAS) and western Bay of Bengal (WBoB) during SLP and RLP. The daily climatology (2003–2019) and anomaly (2020) of different water quality parameters, viz., chlorophyll-a (chl-a), downwelling diffused attenuation coefficient (kd490), and particulate organic carbon (POC) were used in the present study to eliminate seasonal biases and to unravel the signature of lockdown-induced changes in the magnitude of the above water quality parameters. During the total lockdown period, the magnitude of the above parameters reduced significantly in the coastal waters of both the EAS and the WBoB. However, this reduction was more significant in the coastal waters of the WBoB, attributed to a reduction in the supply of anthropogenic nutrients. Among different studied locations, the magnitude of water quality parameters significantly decreased off Chennai and Hooghly, during SLP, which subsequently increased during RLP probably due to reduction in anthropogenic material influx during SLP and increase during RLP. During RLP, the coastal waters off Mahanadi showed a maximum decrease in the magnitude of water quality parameters followed by Mandovi-Zuari, irrespective of these regions’ quantum of anthropogenic material input, possibly due to the higher response time of the ecosystem to reflect the reduction in anthropogenic perturbations. The satellite-retrieved water quality parameters have provided valuable insight to efficiently describe the changes in the health of the Indian coastal environment in terms of phytoplankton biomass and water clarity.

Effect of Addition of Alccofine on the Compressive Strength of Cement Mortar Cubes

In the modern era, many research works are going on throughout the world for finding suitable cementitious material for the replacement of cement since it causes environmental pollution. In this order Fly ash, Silica fume, GGBS, Metakaolin, Micro materials, Quartz powder, etc. are tried out for replacing partially or fully the cement in concrete. A new ultrafine material called Alccofine (AF) which is manufactured from glass wastes is tried out for replacing partially in this research. Compressive strength is one of the important properties of cement. Strength tests are not made on neat cement paste because of difficulties of excessive shrinkage and subsequent cracking of neat cement. Cement mortar of 1:3 mix proportion is used to cast the cubes having an area of 50 cm2 are used for the determination of compressive strength of cement as per IS: 4031-1988 (Part-6). The graded Indian Standard sand (Ennore Sand -ES) confirming to IS: 650-1991 is used for preparing the cubes. In the same mix proportion, the same size cubes are cast with the River Sand (RS) to study the difference of the compressive strength between the Indian standard sand and river sand. Ordinary Portland cement (OPC) and Portland Pozzolana Cements (PPC) are used. The present study is the influence of Alccofine on cement mortar cubes by replacing the cement by Alccofine with various proportions like 5%, 10%, 15%, 20% were cast and tested in the laboratory as per Indian Standard 4301-1988 (Part-6) and the results were analysed and presented in the form of charts and graphs. It is observed that the early age strength is obtained for all the combinations but 10 percent of Alccofine yields more strength than other dosages. Doi: 10.28991/esj-2021-01265 Full Text: PDF

High-throughput genotype-based population structure analysis of selected buffalo breeds.

India is considered as the home tract of some of the best buffalo breeds. However, the genetic structure of the Indian river buffalo is poorly understood. Hence, there is a need to characterize the populations and understand the genetic structure of various buffalo breeds for selection and to design breeding strategies. In this study, we have analyzed genetic variability and population structure of seven buffalo breeds from their respective geographical regions using Axiom Buffalo Genotyping Array. Diversity, as measured by expected heterozygosity, ranged from 0.364 in Surti to 0.384 in Murrah breed, and pair-wise FST values revealed the lowest genetic distance between Murrah and Nili-Ravi (0.0022), while the highest between Surti and Pandharpuri (0.030). Principal component analysis and structure analysis unveiled the differentiation of Surti, Pandharpuri, and Jaffarabadi in first two principal components and at K = 4, respectively, while remaining breeds were grouped together as a separate single cluster and admixed. Murrah and Mehsana showed early linkage disequilibrium (LD) decay, while Surti breed showed late decay. In LD blocks to quantitative trait locis (QTLs) concordance analysis, 4.65% of concordance was observed with 873 LD blocks overlapped with 2,330 QTLs. Overall, total 4,090 markers were identified from all LD blocks for six types of traits. Results of this study indicated that these single-nucleotide polymorphism (SNP) markers could differentiate phenotypically distinct breeds like Surti, Pandharpuri, and Jaffarabadi but not others. So, there is a need to develop SNP chip based on SNP markers identified by sequence information of local breeds.

On Replicates for Comparing Species Densities in Space and Time

ABSTRACT Because benthic foraminifera exhibit spatial heterogeneity, a number of replicates or multiple biological samples are necessary to estimate population densities. In this study, we empirically examine the efficacy of taking four or fewer replicates to differentiate among mean densities in location and time using p-values as a metric for strength of evidence against the null hypothesis of no difference in taxon density. For spatial analyses, four stations along a traverse with four replicates per station were compared with ANOVA within Mission Bay, Texas, using the four most abundant taxa. The p-values for comparing mean densities among stations increased markedly for all taxa, as the number of samples per station decreased from four to two. Using a test level of 0.05, four replicates per station resulted, on average, in significant differences for three of four taxa, three replicates distinguished two of four taxa, and two replicates detected only one difference. For temporal analyses, a single station was sampled in the Indian River Lagoon, Florida, seasonally over four years. Again, p-values increased markedly as the number of samples per station decreased. Using a test level of 0.05, both four- and three-replicate groups were found to separate mean densities among the four years for three of four taxa, two replicates distinguished one taxon, and use of only one replicate could not detect any difference in mean densities among the four years. Based on these and previous field results, we recommend at least four replicates per station for environmental monitoring. However, when examining mean densities within larger ecological entities such as biofacies, just one sample at each station along a single traverse containing four stations in each bay could delineate Mission, Copano, and Mesquite bays in Texas.

Comparative evaluation of single or combined anticoccidials on performance, antioxidant status, immune response, and intestinal architecture of broiler chickens challenged with mixed Eimeria species

Poultry production faces several threats and challenges, one of the most important of which is avian coccidiosis which causes annual losses exceeding US$ 3 billion. Discovering new drugs or combinations of existing anticoccidials has become inevitable to overcome the emergence of coccidiosis resistance. This study evaluated a new combination of maduramicin and diclazuril in comparison to the well-known product Maxiban72 which consisted of narasin and nicarbazin, and the single effect of monensin as treatments for avian coccidiosis. A total of 750 1-day-old Indian River broiler chicks were allocated equally into 5 experimental groups with 6 replicates each as follows: 1) negative unchallenged control group (NC) fed the basal diet; 2) positive control group (PC) received the basal diet and inoculated with Eimeria; 3) PC + 100 mg monensin sodium (Atomonsin)/kg diet (MS); 4) PC + 5 mg maduramicin ammonium (Madramycin) + 2.5 mg diclazuril (Atozuril)/kg diet (MMD); and 5) PC + 40 mg narasin + 40 mg nicarbazin (MaxibanT72)/kg diet (NN). Anticoccidials improved (P < 0.01) growth performance, dressing (%) and carcass yield of inoculated birds compared to untreated-inoculated ones. Erythrogram and leukogram parameters were affected by Eimeria challenge. Total protein, globulin, cholesterol, triglycerides, superoxide dismutase and glutathione peroxidase levels in PC birds' serum were reduced (P < 0.05) while their values of liver enzymes, malondialdehyde and catalase were elevated (P < 0.01) when compared to NC ones. Serum immunoglobulin A, and jejunal gene expressions of interleukin-6 and interferon gamma were increased (P < 0.05) in PC group compared to NC group. Anticoccidial drugs restored values of the aforementioned biomarkers near to those of NC. Jejunal architecture in inoculated birds was improved by the anticoccidial treatments in MS, MMD, and NN. Fecal oocyst counts were significantly reduced in MMD, NN, and MS groups compared to PC group. Conclusively, although all examined anticoccidial drugs were effective in treating Eimeriosis, the anticoccidial combinations in MMD and NN groups were more effective than the single administration of MS in treating avian coccidiosis.

Deterministic and probabilistic health risk assessment for exposure to non-steroidal anti-inflammatory drugs in an Indian river.

This study presents deterministic and probabilistic human health risk assessment using Monte Carlo simulations on exposure to an Indian river, Kaveri, which has been contaminated by non-steroidal anti-inflammatory drugs (NSAIDs). The NSAIDs of concern are naproxen, ibuprofen, aspirin, ketoprofen, and diclofenac. We have considered three exposure scenarios (water ingestion, dermal exposure, and fish ingestion) for four different age groups (0-5, 6-10, 11-18, and 19-70 years). Deterministic risk assessment revealed teenagers to be the most sensitive receptors and water ingestion to be the most crucial pathway contributing to maximum health risk (79 to 86%). Based on the results of Monte Carlo simulations, it was found that the probability of exceeding the deterministic mean risks ranged from 17 to 39% for different exposure routes. High end risk estimates such as 95th percentiles and maximum values of HQ for the entire population did not exceed the USEPA allowable risk. This implies that the NSAIDs at the detected concentrations in the Kaveri river may not pose adverse health effects even in the worst-case scenario. Among the five NSAIDs, diclofenac was found to be the major contributor for health risk. Moreover, the concentration of diclofenac was just one order less than the estimated site-specific threshold concentrations. From sensitivity analysis, the most and the least impactful parameters were found to be water ingestion rate and fish ingestion rate respectively.

Copula based analysis of meteorological, hydrological and agricultural drought characteristics across Indian river basins

AbstractDuration and severity are the two most important parameters used for drought characterization. In this study, we used a bivariate copula‐based approach to understand the joint dependence of drought duration and severity of three different drought types. Three types of bivariate copulas (Gumbel, Frank and Plackett) are estimated for modelling and the best fit copula is selected over 1,162 grid points (at a resolution of 0.5° × 0.5°) of India. Further, the joint dependence of drought duration and severity are analysed to infer important properties in terms of exceedance probability and return periods. Finally, conditional probability and conditional return periods of drought characteristics are also derived, which could be useful for proper planning and management of the water resource system. From the investigation, it is observed that drought events in the Western and Central India are longer and more severe whereas the ones in the south Indian river basins are more frequent but less severe. Moreover, similar results were also obtained for the conditional probability and conditional return periods. This study provides information regarding the severe and longer drought event hotspots all over the study area and thus helpful for the policymakers in developing effective drought prevention and mitigation strategies comprehensively at a national scale.

Insights on Immune Function in Free-Ranging Green Sea Turtles (Chelonia mydas) with and without Fibropapillomatosis.

Simple SummarySea turtles are susceptible to several herpesviruses that are linked to dermatologic diseases, including fibropapillomatosis (FP) and lung-eye-trachea disease. Aside from obvious skin lesions, a number of other sublethal impacts occur in response to these diseases, such as reduced immune function. In this study, we found no relationship between disease presence or severity and T-cell proliferation in green turtles from Florida, USA, at least until the moderate stages of FP; however, natural killer cell activity, a measure of innate immune function, was significantly reduced in turtles with FP compared to tumor-free individuals. This is the first study to examine natural killer cell activity in relation to FP, improving upon our understanding of altered immune system function associated with this disease.Chelonid alphaherpesviruses 5 and 6 (ChHV5 and ChHV6) are viruses that affect wild sea turtle populations. ChHV5 is associated with the neoplastic disease fibropapillomatosis (FP), which affects green turtles (Chelonia mydas) in panzootic proportions. ChHV6 infection is associated with lung-eye-trachea disease (LETD), which has only been observed in maricultured sea turtles, although antibodies to ChHV6 have been detected in free-ranging turtles. To better understand herpesvirus prevalence and host immunity in various green turtle foraging aggregations in Florida, USA, our objectives were to compare measures of innate and adaptive immune function in relation to (1) FP tumor presence and severity, and (2) ChHV5 and ChHV6 infection status. Free-ranging, juvenile green turtles (N = 45) were captured and examined for external FP tumors in Florida’s Big Bend, Indian River Lagoon, and Lake Worth Lagoon. Blood samples were collected upon capture and analyzed for ChHV5 and ChHV6 DNA, antibodies to ChHV5 and ChHV6, in vitro lymphocyte proliferation using a T-cell mitogen (concanavalin A), and natural killer cell activity. Despite an overall high FP prevalence (56%), ChHV5 DNA was only observed in one individual, whereas 20% of turtles tested positive for antibodies to ChHV5. ChHV6 DNA was not observed in any animals and only one turtle tested positive for ChHV6 antibodies. T-cell proliferation was not significantly related to FP presence, tumor burden, or ChHV5 seroprevalence; however, lymphocyte proliferation in response to concanavalin A was decreased in turtles with severe FP (N = 3). Lastly, green turtles with FP (N = 9) had significantly lower natural killer cell activity compared to FP-free turtles (N = 5). These results increase our understanding of immune system effects related to FP and provide evidence that immunosuppression occurs after the onset of FP disease.

Dynamics of microcystins and saxitoxin in the Indian River Lagoon, Florida

Harmful algal blooms that can produce toxins are common in the Indian River Lagoon (IRL), which covers ~250 km of Florida's east coast. The current study assessed the dynamics of microcystins and saxitoxin in six segments of the IRL: Banana River Lagoon (BRL), Mosquito Lagoon (ML), Northern IRL (NIRL), Central IRL (CIRL), Southern IRL (SIRL), and the St. Lucie Estuary (SLE). Surface water samples (n=40) collected during the 2018 wet and 2019 dry season were analyzed to determine associations between toxins and temperature, salinity, pH, oxygen saturation, concentrations of dissolved nutrients and chlorophyll-a, presence of biosynthetic genes for toxins, relative abundance of planktonic species, and composition of the microbial community. The potential toxicity of samples was assessed using multiple mammalian cell lines. Enzyme-Linked Immunosorbent Assays were used to determine concentrations of microcystins and saxitoxin. Overall, the microcystins concentration ranged between 0.01-85.70 µg/L, and saxitoxin concentrations ranged between 0.01-2.43 µg/L across the IRL. Microcystins concentrations were 65% below the limit of quantification (0.05 µg/L), and saxitoxin concentrations were 85% below the limit of detection (0.02 µg/L). Microcystins concentrations were higher in the SLE, while saxitoxin was elevated in the NIRL and BRL. Cytotoxicity related to the presence of microcystins was seen in the SLE during the wet season. No significant patterns between cytotoxicity and saxitoxin were identified. Dissolved nutrients were identified as the most highly related parameters, explaining 53% of microcystin and 47% of saxitoxin variability. Multivariate models suggested cyanobacteria, flagellates, ciliates, and diatoms as the subset of microorganisms whose abundances were maximally correlated with saxitoxin and microcystins concentrations. Lastly, biosynthetic genes for microcystins were detected in the SLE and for saxitoxin in the BRL and NIRL. These results highlight the synergistic roles environmental and biological parameters play in influencing the dynamics of toxin production by harmful algae in the IRL.

Debjani Bhattacharyya. Empire and Ecology in the Bengal Delta: The Making of Calcutta; Sudipta Sen. Ganges: The Many Pasts of an Indian River; Sunil Amrith. Unruly Waters: How Rains, Rivers, Coasts, and Seas Have Shaped Asia’s History

D<scp>ebjani</scp> B<scp>hattacharyya</scp>. <i>Empire and Ecology in the Bengal Delta: The Making of Calcutta</i>; S<scp>udipta</scp> S<scp>en</scp>. <i>Ganges: The Many Pasts of an Indian River</i>; S<scp>unil</scp> A<scp>mrith</scp>. <i>Unruly Waters: How Rains, Rivers, Coasts, and Seas Have Shaped Asia’s History</i>

Evaluation of three approaches to probable maximum precipitation estimation: a study on two Indian river basins

Evaluation of three approaches to probable maximum precipitation estimation: a study on two Indian river basins

Investigating an increase in Florida manatee mortalities using a proteomic approach

Two large-scale Florida manatee (Trichechus manatus latirostris) mortality episodes were reported on separate coasts of Florida in 2013. The east coast mortality episode was associated with an unknown etiology in the Indian River Lagoon (IRL). The west coast mortality episode was attributed to a persistent Karenia brevis algal bloom or ‘red tide’ centered in Southwest Florida. Manatees from the IRL also had signs of cold stress. To investigate these two mortality episodes, two proteomic experiments were performed, using two-dimensional difference in gel electrophoresis (2D-DIGE) and isobaric tags for relative and absolute quantification (iTRAQ) LC–MS/MS. Manatees from the IRL displayed increased levels of several proteins in their serum samples compared to controls, including kininogen-1 isoform 1, alpha-1-microglobulin/bikunen precursor, histidine-rich glycoprotein, properdin, and complement C4-A isoform 1. In the red tide group, the following proteins were increased: ceruloplasmin, pyruvate kinase isozymes M1/M2 isoform 3, angiotensinogen, complement C4-A isoform 1, and complement C3. These proteins are associated with acute-phase response, amyloid formation and accumulation, copper and iron homeostasis, the complement cascade pathway, and other important cellular functions. The increased level of complement C4 protein observed in the red tide group was confirmed through the use of Western Blot.

Reproductive environment of the decreasing Indian river shad in Asian inland waters: disentangling the climate change and indiscriminative fishing threats.

The regional climate has significantly warmed with erratically declining annual rainfall and intensified downpour within a narrower span of monsoon months, which led to an increased trophic state (≈algae) in most inland waters. Freshwater clupeids vitally control the aquatic food chain by grazing on algae. Despite increasing food availability, IUCN Red List® revealed 16 freshwater clupeids with a decreasing population trend. We investigated one such species' reproductive dependencies, Gudusia chapra (Indian river shad), in the lower Gangetic drainage (India) under a mixed context of climate change and overfishing. Monthly rainfall (≥ 60-100 mm) and water temperature (≥ 31-32 °C) are key breeding cues for females. The regional climate seems inclined to fulfill these through the significant part of the breeding season, and indeed the species has maintained consistent breeding phenology over 20 years. Other breeding thresholds relevant to fishing include size at first maturity (≥ 6.8 cm; reduced by ~ 25-36%) and pre-spawning girth (Girthspawn50 ≥ 7 cm; first record). Girthspawn50 is a proxy of the minimum mesh size requirement of fishing nets to allow safe passage of "gravid" females (+ 22% bulged abdomen) and breed. The operational fishing nets (3-10 cm mesh) probably have been indulged in indiscriminative fishing of gravid females for generations. Under a favorably changing climate and food availability, existing evidence suggests a fishery-induced evolution in regional females (to circumvent such mesh sizes) through earlier maturation/puberty at smaller sizes. It could be an early warning sign of population collapse (smaller females → lessening fecundity → fewer offspring). Overfishing seemed to be a bigger threat than climate change.

Flushing rates and hydrodynamical characteristics of Mosquito Lagoon (Florida, USA).

A hydrodynamic model is applied to a domain encompassing Mosquito Lagoon and a segment of north Indian River Lagoon on the east coast of Florida with the goals of (1) describing the hydrodynamic regime of the area according to existing conditions and (2) to determine the flushing rates of the system after introducing a hypothetical pollutant (numerical dye tracer). Results from the 1-year simulation agree with observations and show that the Mosquito Lagoon (ML) and North Indian River Lagoon (NIRL) are dominated by the nontidal (low frequency) water level oscillations except at the northernmost part of the ML where the influence of tidal renewal dominates. The global tracer application results reveal that only the two northernmost segments of Mosquito Lagoon (ML-ac and ML-df) reach 50% of tracer concentrations (R50) within the year of simulation (day 19 and day 176 respectively). The five (discrete) segments tracer study resulted in lower R50 values and the hypothetical pollutant is removed (flushed) from each of the segments within the year and with an averaged renewal time value for the Mosquito Lagoon basin of 98days. Observed throughout the simulation period is the interaction across the different segments and a predominantly two-layered water mass exchange through the Haulover Canal. Most significant is that the resulting renewal times (R50) indicate the existence of three dynamically distinct sections within Mosquito Lagoon. These findings aid in the identification of poorly flushed zones and serve as a baseline for the duration and possible propagation of detrimental conditions such as a harmful algal bloom (HAB) event or a contaminant spill.

Adaptation Actions to Reduce Impairment of Indian River Lagoon Water Quality Caused by Climate Change, Florida, USA

Results of a vulnerability assessment of the Indian River Lagoon to climate change indicate future risks to water quality can be mitigated through adaptation actions targeting anticipated increases in pollutant loads from wastewater treatment plants, on site treatment and disposal systems, and surface water storage and conveyance infrastructure. Nine adaptation actions are recommended and if successfully implemented could reduce risks caused by climate change by fifty percent. The mitigating benefits of these actions are expected to cascade into other elements of the Lagoon, like living resources and habitats. The results and recommendations of this investigation are novel because they are based upon site-specific data and anticipated risks prioritized using a repeatable and defensible methodology. Furthermore, the focus and deliverables were informed by stakeholder involvement to facilitate utility to and implementation by resource practitioners. The next challenge is to implement, monitor, and revise each adaptation action as warranted. This will require a substantial increase in funding dedicated to the Lagoon’s restoration and coherently managed for decades. Strengthened collaboration between local, state, and federal programs is necessary to enhance the probability of successfully reducing future climate-related water quality impairments and facilitating the emergence of a more resilient, climate-ready estuary.

Replacing a third-generation wave model with a fetch based parametric solver in coastal estuaries

Within a restricted estuarine environment, the use of third-generation wave models for predicting wave heights can be computationally expensive, signaling a need for model development that reduces the computational costs of existing coupled hydrodynamic models. This study focuses on the development and testing of a parametric wave solver that incorporates four wave height formulations (SMB, SPM, TMA, and CEM) for predicting wave properties in a restricted estuarine environment. The emphasis is on improved efficiency without affecting accuracy, allowing for ensemble wave-surge forecasting to be performed on desktop computational resources. Evaluation of the performance of the parametric solver is twofold, first the parametric solver is compared to a third-generation wave model, Simulating Waves Nearshore (SWAN), for the Indian River Lagoon domain, which lies on Florida's east coast. Then both the parametric solver and SWAN are compared to in-situ ADCP wave data at a point in the estuarine domain. The creation of three different synthetic wind fields allows for model comparison, with wind fields permitting testing of the parametric model in order to reproduce (1) fully developed conditions, (2) wind speed variability, and (3) wind direction variability in tropical storm level wind events. For consistency comparison, wave height solutions over the same domain are generated by SWAN and the parametric models. Comparisons made between the parametric model performance and SWAN show a 4-member parametric model is accurate to within 87% globally, with a runtime improvement of over two orders of magnitude compared to SWAN. The parametric model's ensemble average wave height solution was 5.5% less than the in-situ measured wave height; the SWAN solution was 5.5% greater than the measured wave height at the same location. Therefore, the parametric wave model proves to be a viable alternative to running an expensive third-generation wave model for predicting waves in an enclosed estuarine system.