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Eastern Oyster (Crassostrea virginica) Filtration Efficiency of Chlorophyll-a under Dynamic Conditions in the Hudson-Raritan Estuary at Pier 40, New York City  [PDF]
Jane E. Perrino, Dennis R. Ruez Jr.
Open Journal of Ecology (OJE) , 2019, DOI: 10.4236/oje.2019.97019
Abstract: Eastern oyster (Crassostrea virginica) abundance has declined severely over the past century along the Atlantic and Gulf coasts of the United States. For varied reasons, overfishing among the foremost, bivalves no longer make up considerable reefs as was common. While discourse continues on oyster restoration and augmentation, gaps in knowledge of C. virginica and regional environmental interactions remain. Our primary aim was to examine the C. virginica filter feeding of phytoplankton in the Hudson River Estuary, New York City. Secondarily, this study examined the filtration of these oysters in relation to environmental attributes. Chlorophyll-a, the predominant photosynthesizing pigment in red and green algae, is an indicator of phytoplankton productivity in aquatic settings. Crassostrea virginica consumes first-tier plankton from the water column’s seston; thus analysis of chlorophyll-a content allows estimating phytoplankton concentrations, from which oyster filtration efficiency (FE) was quantified. Water conditions (temperature, dissolved oxygen, pH, salinity, turbidity, tide and flow rate) also were recorded. Spectrophotometric determination of chlorophyll-a concentration methodology was derived from the Standard Methods text favored by the US EPA. This project compared real-time Hudson River Estuary (HRE) water samples prior to passing through a contained oyster reef and samples of water post-filtration. This sampling scenario was unique as the contained reef used was fed by HRE water. Most studies on oyster filtration have been laboratory-based, and few assessed oysters in the field. This study took place at Pier 40, the River Project Wetlab, lower Hudson River along Manhattan. The FE of this reef was calculated for two months during various environmental states which can be the basis of future investigations. Statistically significant differences were found between pre- and post-filtration water samples (Z = 4.620, p < 0.001). This study provides a glimpse at how the oysters fare in the HRE environment and expands upon known oyster ecological services and environmental interactions.
Bacteria of fecal origin in mangrove oysters (Crassostrea rhizophorae) in the Cocó River estuary, Ceará State, Brazil
Silva, Ana I.M.;Vieira, Regine H.S.F.;Menezes, Francisca G.R.;Fonteles-Filho, Antonio A.;Torres, Regina C.O.;Sant'Anna, Ernani S.;
Brazilian Journal of Microbiology , 2004, DOI: 10.1590/S1517-83822004000100021
Abstract: this study was aimed at evaluating the microbiological quality of mangrove oysters (crassostrea rhizophorae), collected at a natural oyster bed in the estuary of cocó river (fortaleza, ceará, brazil). mpn values were used for estimating the total (tc) and fecal (fc) coliforms and enterococcus spp. tc and fc mpn values in the whole muscle and intervalve liquid ranged from <1.8 to >1,600/g and from <1.8 to 920/g, respectively. the mpn estimates for enterococcus spp. were between <3.0 and >1,100/g. no correlation was found between the physico-chemical parameters (temperature, salinity and ph) of the surrounding water and the bacteriological contamination levels found in the tested oysters. the only correlation found was between tc and fc values. enterococcus spp. strains were isolated and subjected to biochemical tests for species identification. the capacity of those strains for production of a bacteriocin-like inhibitory substance was tested using the escherichia coli strain atcc 25922 as a testing organism. only one, e. faecalis, out of 121 enterococcus strains tested, presented the inhibitory activity.
Seasonal movements of American horseshoe crabs Limulus polyphemus in the Great Bay Estuary, New Hampshire (USA)  [cached]
Susanne Y. SCHALLER, Christopher C. CHABOT, Winsor H. WATSON III
Current Zoology , 2010,
Abstract: The goal of this study was to determine the year round movement patterns of American horseshoe crabs, Limulus polyphemus, in the Great Bay Estuary, New Hampshire (USA) by using acoustic telemetry to track the movements of 37 adult Limulus, for periods ranging from 2 to 31 months. During the winter (December-March) horseshoe crabs moved very little. In the spring, when water temperatures exceeded 11oC, horseshoe crabs moved at least 1 km further up into the estuary to shallower subtidal areas about a month prior to spawning. The mean distance traveled during spring migrations was 2.6 ± 0.5 (n=20) km up the estuary. Mating occurred in May and June and during these months animals spent most of their time in shallow subtidal areas adjacent to mating beaches. In the summer (July-August), animals moved 1.5 ± 0.5 (n=26) km down the estuary, towards the ocean, and ranged widely, using extensive portions of the estuary. In the fall (September-November) movement was more limited (0.5 ± 0.5 km; n = 24) while animals settled into wintering locations, where they remained until spring. The mean annual linear range for all animals was 4.5 ± 0.3 km (n =35) and the maximum distance traveled by an individual horseshoe crab within one year was 9.2 km. There was no evidence that any of the horseshoe crabs tracked during this study left the estuary [Current Zoology 56 (5): 587–598, 2010].
Cloning, expression and purification of tRNAPro from bacteria Enterococcus faecalis  [PDF]
Boyarshin K. S.,Kriklivyi I. A.,Yaremchuk A. D.,Tukalo M. A.
Biopolymers and Cell , 2009,
Abstract: Aim. To elaborate the method of expression and purification of bacteria Enterococcus faecalis tRNAPro transcript. Methods. tRNA, co-expressed in vitro with cis-hydrolytical ribozyme, was purified by high performance liquid chromatography using anion-exchange chromatographic column. Results. A satisfactory yield of high purity preparation was obtained. A transcript of tRNAPro exhibits acceptor activity in aminoacylation reaction. Conclusions. The method developed may be introduced in laboratory practice including the obtaining of other tRNAs.
Role and Value of Nitrogen Regulation Provided by Oysters (Crassostrea virginica) in the Mission-Aransas Estuary, Texas, USA  [PDF]
Jennifer Beseres Pollack, David Yoskowitz, Hae-Cheol Kim, Paul A. Montagna
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0065314
Abstract: Suspension-feeding activities of oysters impart a potentially significant benefit to estuarine ecosystems via reduction of water column nutrients, plankton and seston biomass, and primary productivity which can have a significant impact on human well-being. This study considered nitrogen regulation by eastern oysters Crassostrea virginica in the Mission-Aransas Estuary, Texas, USA, as a function of denitrification, burial, and physical transport from the system via harvest. Oyster reefs were estimated to remove 502.5 kg N km?2 through denitrification of biodeposits and 251.3 kg N km?2 in burial of biodeposits to sediments. Nitrogen is also physically transported out of the estuary via harvest of oysters. Commercial harvest of oysters in the Mission-Aransas Estuary can remove approximately 21,665 kg N per year via physical transport from the system. We developed a transferable method to value the service of nitrogen regulation by oysters, where the potential cost equivalent value of nitrogen regulation is quantified via cost estimates for a constructed biological nutrient removal (BNR) supplement to a wastewater treatment plant. The potential annual engineered cost equivalent of the service of nitrogen regulation and removal provided by reefs in the Mission-Aransas Estuary is $293,993 yr?1. Monetizing ecosystem services can help increase awareness at the stakeholder level of the importance of oysters beyond commercial fishery values alone.
Shoreline Change along Sheltered Coastlines: Insights from the Neuse River Estuary, NC, USA  [PDF]
Lisa Cowart,D. Reide Corbett,J.P. Walsh
Remote Sensing , 2011, DOI: 10.3390/rs3071516
Abstract: Coastlines are constantly changing due to both natural and anthropogenic forces, and climate change and associated sea level rise will continue to reshape coasts in the future. Erosion is not only apparent along oceanfront areas; shoreline dynamics in sheltered water bodies have also gained greater attention. Additional estuarine shoreline studies are needed to better understand and protect coastal resources. This study uses a point-based approach to analyze estuarine shoreline change and associated parameters, including fetch, wave energy, elevation, and vegetation, in the Neuse River Estuary (NRE) at two contrasting scales, Regional (whole estuary) and Local (estuary partitioned into eight sections, based on orientation and exposure). With a mean shoreline-change rate of –0.58 m yr?1, the majority (93%) of the NRE study area is eroding. Change rates show some variability related to the land-use land-cover classification of the shoreline. Although linear regression analysis at the Regional Scale did not find significant correlations between shoreline change and the parameters analyzed, trends were determined from Local Scale data. Specifically, erosion rates, fetch, and wave exposure increase in the down-estuary direction, while elevation follows the opposite trend. Linear regression analysis between mean fetch and mean shoreline-change rates at the Local Scale provide a first-order approach to predict shoreline-change rates. The general trends found in the Local Scale data highlight the presence of underlying spatial patterns in shoreline-change rates within a complex estuarine system, but Regional Scale analysis suggests shoreline composition also has an important influence.
Isolation, identification and antimicrobial activity of lactic acid bacteria from the Bahía Blanca Estuary
Sica,María G; Olivera,Nelda L; Brugnoni,Lorena I; Marucci,Patricia L; López-Cazorla,Andrea C; Cubitto,María A;
Revista de biología marina y oceanografía , 2010, DOI: 10.4067/S0718-19572010000300003
Abstract: this study analyzed the biodiversity of lactic acid bacteria present in the bahía blanca estuary and their antimicrobial activity against pathogens associated with the cultivation of salmonid. a total of 21 lactic acid bacteria (lab) strains were isolated from superficial sediments and fish of the estuary. the fish species were selected from those that spend most of their life cycle in the estuary. according to 16s rdna analysis, isolates were affiliated with the genera lactobacillus, pediococcus, leuconostoc, enterococcus and weissella. the predominant lab isolates from the fish species belonged to weissella viridescens, which was isolated from three of the four species analyzed. none of the lab species isolated from fish was found in sediments. the agar diffusion method was used for detection of antagonistic activity against listeria monocytogenes, yersinia ruckeri, aeromonas salmonicida subsp. salmonicida and two strains of lactococcus garvieae. all the isolates exhibited some degree of antagonistic activity against l. monocytogenes, y. ruckeri and both strains of lc. garvieae. twelve strains were found to be inhibitory for a. salmonicida. this study is the first report on the diversity of lactic acid bacteria in a coastal marine environment and fish from argentina. the sediments and fish analyzed showed microbial strains with the ability to suppress pathogen growth under in vitro conditions, suggesting their potential as biological control agents for aquaculture and fish processing.
MERIS Retrieval of Water Quality Components in the Turbid Albemarle-Pamlico Sound Estuary, USA  [PDF]
Leonid G. Sokoletsky,Ross S. Lunetta,Michael S. Wetz,Hans W. Paerl
Remote Sensing , 2011, DOI: 10.3390/rs3040684
Abstract: Two remote-sensing optical algorithms for the retrieval of the water quality components (WQCs) in the Albemarle-Pamlico Estuarine System (APES) were developed and validated for chlorophyll a (Chl). Both algorithms were semi-empirical because they incorporated some elements of optical processes in the atmosphere, water, and air/water interface. One incorporated a very simple atmospheric correction and modified quasi-single-scattering approximation (QSSA) for estimating the spectral Gordon’s parameter, and the second estimated WQCs directly from the top of atmosphere satellite radiance without atmospheric corrections. A modified version of the Global Meteorological Database for Solar Energy and Applied Meteorology (METEONORM) was used to estimate directional atmospheric transmittances. The study incorporated in situ Chl data from the Ferry-Based Monitoring (FerryMon) program collected in the Neuse River Estuary (n = 633) and Pamlico Sound (n = 362), along with Medium Resolution Imaging Spectrometer (MERIS) satellite imagery collected (2006–2009) across the APES; providing quasi-coinciding samples for Chl algorithm development and validation. Results indicated a coefficient of determination (R2) of 0.70 and mean-normalized root-mean-squares errors (NRMSE) of 52% in the Neuse River Estuary and R2 = 0.44 (NRMSE = 75 %) in the Pamlico Sound—without atmospheric corrections. The simple atmospheric correction tested provided on performance improvements. Algorithm performance demonstrated the potential for supporting long-term operational WQCs satellite monitoring in the APES.
A Restoration Suitability Index Model for the Eastern Oyster (Crassostrea virginica) in the Mission-Aransas Estuary, TX, USA  [PDF]
Jennifer Beseres Pollack, Andrew Cleveland, Terence A. Palmer, Anthony S. Reisinger, Paul A. Montagna
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0040839
Abstract: Oyster reefs are one of the most threatened marine habitats on earth, with habitat loss resulting from water quality degradation, coastal development, destructive fishing practices, overfishing, and storm impacts. For successful and sustainable oyster reef restoration efforts, it is necessary to choose sites that support long-term growth and survival of oysters. Selection of suitable sites is critically important as it can greatly influence mortality factors and may largely determine the ultimate success of the restoration project. The application of Geographic Information Systems (GIS) provides an effective methodology for identifying suitable sites for oyster reef restoration and removes much of the uncertainty involved in the sometimes trial and error selection process. This approach also provides an objective and quantitative tool for planning future oyster reef restoration efforts. The aim of this study was to develop a restoration suitability index model and reef quality index model to characterize locations based on their potential for successful reef restoration within the Mission-Aransas Estuary, Texas, USA. The restoration suitability index model focuses on salinity, temperature, turbidity, dissolved oxygen, and depth, while the reef quality index model focuses on abundance of live oysters, dead shell, and spat. Size-specific Perkinsus marinus infection levels were mapped to illustrate general disease trends. This application was effective in identifying suitable sites for oyster reef restoration, is flexible in its use, and provides a mechanism for considering alternative approaches. The end product is a practical decision-support tool that can be used by coastal resource managers to improve oyster restoration efforts. As oyster reef restoration activities continue at small and large-scales, site selection criteria are critical for assisting stakeholders and managers and for maximizing long-term sustainability of oyster resources.
Numerical Modelling Sediment-Bacteria Interaction Processes in the Severn Estuary  [PDF]
Guanghai Gao, Roger A. Falconer, Binliang Lin
Journal of Water Resource and Protection (JWARP) , 2011, DOI: 10.4236/jwarp.2011.31003
Abstract: Faecal bacteria exist in both free-living and attached forms in estuarine waters. The deposition of sediments can take faecal bacteria out of the water column and to the bed. The sediments can subsequently be re-suspended to the water column, which can then lead to re-suspension of the faecal bacteria of the attached forms back to the water column. Therefore, the fate and transport of faecal bacteria is highly related to the governing sediment transport processes, particularly where these processes are significant, such as the Severn Estuary, UK. However, little attempt has been made to model such processes in terms of predicting the impact of the sediment fluxes on faecal bacteria levels. Details are given of the refinement of a numerical model of faecal bacteria transport, where the sediment transport processes are significant. After testing the sediment-bacteria interaction model favourably against known results in previous study, the model was applied to the Severn Estuary and Bristol Channel, UK, to investigate the impact of suspended sediment fluxes on the corresponding faecal bacteria transport processes. The model predictions have proved to be encouraging, with the results being compared to a traditional faecal bacteria modelling approach, where sediment bacteria interactions were not included. The new model provides improved predictions of faecal bacteria concentrations when sediment transport is included and for the Bristol Channel Severn Estuary it can be seen that the effects of the sediments on the bacterial levels in the water column can be significant.
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