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At least 19 recordsLinked to original sources
PubMed1977

Concentration of enteroviruses from large volumes of turbid estuary water.

A method is described for the efficient concentration of viruses from large volumes of highly turbid estuary water. Virus in acidified seawater in the presence of aluminum chloride is adsorbed to a 10-in. (about 25.4 cm) fibreglass depth cartridge and 2- and 0.65-micron epoxy-fibreglass filters in series. This filter series is capable of efficiently adsorbing enteroviruses from 50 U.S. gallons (about 190) of estuary water of varying salinity and turbidity. Adsorbed viruses were eluted from the filters with glycine buffer (pH 11.5) and the eluate reconcentrated by using a precipitate formed by the addition of ferric chloride. Viruses were eluted from this precipitate with fetal calf serum. Using this procedure, four different enteroviruses in 50 gallons (about 190) of estuary water were concentrated 9 000- to 12 000-fold with an overall efficiency of 41%.

Aluminum↗
PubMed2024

Land use conversion to uplands significantly increased the risk of antibiotic resistance genes in estuary area.

Land use conversion in estuary wetlands may affect the transmission of antibiotic resistance genes (ARGs), while the risk rank of the ARGs and the change of clinically relevant ARGs under various land-use types are not well understood. This study used metagenomics to reveal the diversity and abundance of ARGs across five distinct land uses: reed wetland, tidal flat, grassland, agricultural land and fallow land, as well as their distribution and potential health risks. Results showed that high numbers of ARG subtypes and classes were detected irrespective of land-use types, notably higher in agricultural land (144 ARG subtypes). The most shared ARG subtypes were multidrug resistance genes across all the land uses (29 subtypes, 4.7 × 10-2-1.5 × 10-1 copies per 16S rRNA gene copy). Proteobacteria and Actinobacteria were primary ARG hosts, with 18 and 15 ARGs were found in both of them, respectively. The ARG subtype mdtB was the most dominant clinical ARG detected with 90 % amino acid identity. The change of ARGs exhibited a consistent trend across land uses in terms of health risk ranks, with the highest observed in fallow land and the lowest in reed wetland. This study reveals the distribution pattern of ARGs across various land-use types, and enhances our understanding of the potential health risks associated with ARGs in the context of coastal wetland conversion in estuary areas.

Estuaries↗
PubMed1979

Schistosome dermatitis in the Swan Estuary, Western Australia.

The avian blood fluke, Austrobilharzia terrigalensis (Trematoda: Schistosomatidae), is recorded in Western Australia for the first time, and is implicated as the cause of dermatitis among users of the Swan estuary in Perth. Quantitative data provided by a questionnaire sent to affected people showed that infection occurred from November to March in the shallows throughout the "middle" estuary and that children from five to 14 years old were most frequently affected. Most cases of dermatitis were contracted between 11 a.m. and 12 noon--the time of day when the emergence of A. terrigalensis cercariae from the intermediate host, Velacumantus australis, reaches a peak. Exposure times varied considerably, but were generally between 30 and 90 minutes, with dermatitis appearing 12 to 24 hours later. The lesions, which were sometimes widespread over the body and itched severely, persisted for one to two weeks and longer if they were secondarily infected. Approximately 38% of affected people consulted doctors about their condition. These results are discussed in relation to findings on the ecology of the parasite's intermediate and definitive hosts.

Adolescent↗
PubMed1977

Release of polychlorinated biphenyls (PCB) in a salt-wedge estuary as induced by dredging or contaminated sediments.

An evaluation of the input of polychlorinated biphenyls (PCB) in the Duwamish River, Seattle, Wash., resulting from the dredging of contaminated sediments is presented. The mean concentrations of PCB during the monitoring period were 12.8 to 24.5 ng/liter in water and 1.03 to 1.77 microgram/g dry weight in suspended particulate matter. These values were within the ranges normally observed in the river, suggesting that the dredging operations did not induce a significant PCB pulse of potential hazard to the estuary. The fractionation of PCB in suspended particulate matter was determined by computing component concentration ratios, KN(d). These quantities indicate an enrichment factor of 10(5) from ambient water. Based on the ambient PCB load and normal discharge, the input of PCB into Puget Sound via the Duwamish River was estimated to be 36 kg/year.

Polychlorinated Biphenyls↗
PubMed1978

Pathology of hepatomas and other liver abnormalities in English sole (Parophrys vetulus) from the Duwamish River estuary, Seattle, Washington.

Liver abnormalities were found, by gross and histopathologic examination, in 92% of the English sole (Parophrys vetulus) from the Duwamish River Estuary, Seattle, Washington. Hepatomas were found in 32% (20 of 62) of the English sole. Other observed liver aberrations included increased fatty vacuolation, congestion, structure disarray, increased size and number of melanin-macrophage centers, centrolobular fatty degeneration and necrosis, increased amounts of perivascular connective tissue, intercellular melanin deposits, and hepatocellular hypertrophy often associated with the presence of bizarre nuclei and/or multiple nucleoli. Livers evidencing microscopic lesions were usually discolored. Livers containing hepatomas were often mottled yellow or tan and brown; occasionally, hepatomas were visible as tan or white nodules. Although the cause(s) of the liver abnormalities has not been conclusively identified, chemical analyses of Duwamish River English sole have detected polychlorinated biphenyl (PCB) levels of about 1.5 ppm (dry wt) in total body tissue. Many of the above-mentioned abnormalities, with the exception of hepatomas, have been observed in fish exposed to PCB's.

Animals↗
PubMed1979

Residues of polychlorinated biphenyls and DDT in water and sediment of the St. Lucie Estuary, Florida, 1977.

sigma DDT residues in the St. Lucie River bottom sediments increased after Lake Okeechobee water was discharged through the St. Lucie Canal into the area. sigma DDT levels were highest in sediment samples from the Palm City area, ranging from 1.8 ppb to 6.15 ppb. Sediment samples from the A1A Highway Bridge area contained 1.6-6.8 ppb Aroclor 1254. Levels of polychlorinated biphenyls (PCBs) and sigma DDT in sediment samples from the junction of the St. Lucie and Indian Rivers were not detectable. Surface water samples from the estuary did not show any detectable DDT or PCB residues.

DDT↗
PubMed1979

PCB removal from the Duwamish River estuary: implications to the management alternative for the Hudson River PCB cleanup.

The results of the Duwamish River PCB cleanup and recovery project are discussed as a basis for comparison in selecting potential management alternatives for removing PCB residues in the Hudson River. Application of the Pneuma dredge system at the Duwamish River spill site removed approximately 92% of the PCBs spilled. No significant changes in the PCB load of suspended matter and water column were observed. These results suggest that a carefully planned dredge/disposal operation can be effective in minimizing environmental impacts in the Hudson River. On the basis of observations of the Duwamish case, the existing baseline data on the distribution of PCBs in the Hudson River, and the removal alternatives and associated environmental tradeoffs, hot spot dredging is recommended as the best practical alternative.

Accidents↗
PubMed1977

Numerical taxonomy of heavy metal-tolerant bacteria isolated from an estuary.

A total of 230 strains of metal-tolerant bacteria from water and sediment samples collected in Chesapeake Bay were isolated on a medium containing cobalt, lead, mercury, or molybdenum. In addition, a set of 71 cultures were simultaneously isolated on glucose tryptone yeast extract agar medium without metals. Twenty-three reference strains were also included in the numerical taxonomy study of these bacteria, bringing the grand total of strains examined to 324. All strains were examined for 112 biochemical, cultural, morphological, and physiological characters. The taxonomic data obtained were analyzed by computer and the simple matching (SSM) and Jaccard (SJ) coefficients were calculated. Clustering achieved by unweighted average linkage is presented and, from sorted similarity matrices and dendrograms, 294 strains, i.e., 97% of the total, were recovered in 12 phenetic groups defined at the 75 to 80% similarity level. Among the strains there were nine phena presumptively identified as Bacillus, Erwinia, Mycobacterium, Pseudomonas, and coryneforms. From the results of the taxonomic study, it is concluded that metal tolerance in estuarine water and sediment bacteria occurs among a restricted range of taxa distributed throughout the estuarine environment.

Actinomycetales↗
PubMed2025

Picocyanobacteria in the Chesapeake Bay: isolation, diversity, and adaptation.

Tiny unicellular cyanobacteria or picocyanobacteria (0.5-3 µm) are important due to their ecological significance. Chesapeake Bay is a temperate estuary that contains abundant and diverse picocyanobacteria. Studies of Chesapeake Bay picocyanobacteria in the past 20 years led to the finding of new members of subcluster 5.2 Synechococcus. They laid the foundation for revealing the ecophysiology, biogeography, genomics, and molecular evolution of picocyanobacterial in the Chesapeake Bay and other coastal estuaries. The Bay picocyanobacteria are known to better tolerate the changes in temperature, salinity, and heavy metals compared to their coastal and open-ocean counterparts. Many picocyanobacteria isolated from the Bay contain rich toxin-antitoxin (TA) genes, suggesting that the TA system may provide them with a genetic advance to cope with variable estuarine environments. Distinct winter and summer picocyanobacteria are present in the Bay, suggesting a dynamic seasonal shift of the picocyanobacterial community in the temperate estuary. While the Bay contains subcluster 5.2 Synechococcus, it also contains freshwater Synechococcus, Cyanobium, and marine Synechococcus due to river influx and the ocean's tidal influence. Some Chesapeake Bay picocyanobacterial clades were found in the Bering Sea and Chukchi Sea, showing a link between the Bay and polar picocyanobacteria. Genomic sequences of estuarine picocyanobacteria provide new insight into the taxonomy and evolution of freshwater, estuarine, and marine unicellular cyanobacteria. Estuaries connect freshwater and marine ecosystems. This overview attempts to extend what we learned from Chesapeake Bay picocyanobacteria to picocyanobacteria in freshwater and marine waters.

Chesapeake Bay↗
PubMed2026

The Spatial and Temporal Repeatability of Genomic Responses to Natural Selection as Demonstrated in Stickleback Populations Experiencing Highly Dynamic Environments.

The evolution of genotypic parallelism under shared environmental conditions provides strong evidence for the role of natural selection. However, analyses typically examine genomic signatures of selection long after the putative selection event and only assess the repeatability of responses across spatial population replicates. This impedes our ability to attribute a particular response to a given selection pressure and to distinguish non-parallel responses caused by stochastic processes from those caused by local selection. As such, the consistency of natural selection over space and time is unknown, and the role of persistent local selection pressures is unclear. Here, we leveraged the natural bar-built estuary system of Santa Cruz, California, to examine the repeatability of seasonal genomic change in threespine stickleback (Gasterosteus aculeatus) over space and time. By comparing allele-frequency shifts that are shared across locations (spatial repeatability) with those that are shared across years within locations (temporal repeatability), we identified both spatially shared and local components of putative selection. We found that repeated seasonal outlier responses occurred more often than expected under a neutral null model. Although repeatability declined as the number of estuaries sharing an outlier increased, enrichment above neutral expectations increased with broader spatial sharing, particularly for outliers repeated across both years. While the precise outlier SNPs varied across years, estuary-specific patterns of responses were broadly consistent, suggesting an important role for local conditions. Together, our findings show that temporal sampling can reveal components of putative selection that would be missed from spatial comparisons alone. More broadly, they highlight the importance of examining repeatability over both space and time to understand the parallel and non-parallel components of adaptive genomic change.

Animals↗
PubMed2026

Heavy-metal stress shapes habitat-specific microbial survival strategies in estuarine environments.

Estuarine ecosystems face increasing heavy metal pollution from rapid urbanization and industrialization, yet the microbial adaptive strategies to multiple metal stressors across different habitats remain poorly understood. This study investigated the diversity and composition of bacterial and fungal communities across free-living (FL), particle-attached (PA), and sediment (SE) fractions from three estuaries with varying heavy metal contamination, and further investigated functional adaptations of bacterial communities. High-throughput amplicon sequencing revealed habitat-specific communities, with SE hosting the highest alpha diversity and enrichment of metal-resistant genera such as Woeseia and Sva1033. Environmental filtering, particularly by Zn, was the dominant driver shaping bacterial assemblages across all habitats, whereas fungal communities displayed greater stochastic assembly patterns. Analysis of 44 high-quality bacterial metagenome-assembled genomes (MAGs) revealed diverse metal resistance genes (cusA, znuB, and zntA), along with enriched metabolic pathways for carbon, nitrogen, and sulfur cycling. Notably, both active efflux/oxidative stress defense and indirect immobilization mechanisms were observed across all habitats, but their relative importance differed: FL and PA communities exhibited a greater reliance on active metal efflux (czcAB) and oxidative stress defense (trxAB) to maintain intracellular homeostasis, whereas SE communities displayed a stronger genomic potential for sulfate reduction (dsrAB) that may contribute to metal immobilization through sulfide precipitation. This metabolic partitioning highlights the complementary roles of different habitats in mediating metal toxicity and biogeochemical cycling, providing new insights into microbial resilience in polluted estuaries and underscoring the urgency of addressing heavy-metal contamination in these critical ecosystems.

Estuaries↗
PubMed1976

Influence of sewage discharge on nitrogen fixation and nitrogen flux from coral reefs in Kaneohe Bay, Hawaii.

Nitrogen fixation was investigated in Kaneohe Bay, Oahu, Hawaii, a subtropical eutrophic estuary, by using the acetylene reduction technique on algal samples. No active, planktonic, N2-fixing blue-green algae or bacteria were observed. However, Calothrix and Nostoc capable of fixing N2 were cultured from navigational buoys and dead coral heads. Nitrogen fixation associated with these structures was greater in the middle sector than in the south and north sectors of the estuary. Experiments demonstrated that the fixation was photosynthetically dependent. Examination of the data showed that there was no significant correlation between rates of nitrogen fixation and concentration of combined nitrogen compounds in the Bay water. Fixation was significantly correlated to the inorganic N/P (atomic) ratio in the south and middle sectors but not in the north sector. The nutrient data indicate there was a flux of combined nitrogen, but not phosphate, from the reef flats.

Acetylene↗