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1.
Chemosphere ; 286(Pt 1): 131668, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34346346

RESUMEN

Bacterial degradation is unequivocally considered as an important way for the cleanup of polycyclic aromatic hydrocarbon (PAHs) in the aquatic environment. However, the diversity and distribution of PAH-degrading bacterial communities and PAH degradation-related genes (PAHDGs) in ambient environment need to be investigated. In this study, bacteria in the water of the Pearl River Estuary (PRE) were initially separated as the particle-attached bacteria (PAB) and free-living bacteria (FLB), and were further characterized using metagenomic approaches. Proteobacteria (80.1 %) was identified as the most abundant PAH-degrading phylum in the PRE water, followed by Bacteroidetes, Actinobacteria, and Firmicutes. A substantial difference in the community structure was observed between PAH-degrading PAB and FLB. Both of PAH-degrading bacteria and PAHDGs were enriched on the suspended particulate matters (SPMs), with the range of enrichment factor (EF) from 7.84 × 104 to 6.64 × 106 (PAH-degrading bacteria) and from 1.14 × 103 to 1.76 × 105 (PAHDGs). The levels of PAH-degrading bacteria 16 S rRNA genes and PAHDGs on the SPMs were both significantly correlated with those in the aqueous phase (AP) in the PRE water (p < 0.05), indicating a dynamic distribution of PAH-degrading bacteria between these two phases. The total PAH concentrations on the SPMs of the PRE water were also significantly correlated with the total PAHDG levels in the PAB (p < 0.05). Our results suggested that the SPMs could be the important compartment for the elimination of PAHs from the aquatic environment.


Asunto(s)
Hidrocarburos Policíclicos Aromáticos , Bacterias/genética , Biodegradación Ambiental , Estuarios , Sedimentos Geológicos , Material Particulado , Hidrocarburos Policíclicos Aromáticos/análisis , Ríos
2.
Biol Trace Elem Res ; 200(1): 402-412, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33619638

RESUMEN

Perna perna mussels, abundant throughout the Brazilian coast, are routinely applied as bioindicators in environmental monitoring actions due to their sessile and filter-feeding characteristics. In addition, they are noteworthy for their food importance, especially for coastal populations. In this context, the aim of this study was to investigate elemental contamination in commercially marketed and highly consumed P. perna samples from the highly impacted Guanabara Bay, Rio de Janeiro, Brazil. A total of 30 mussels were sampled, and elemental concentrations (As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, V, and Zn) were determined in adductor muscle samples by inductively coupled plasma mass spectrometry (ICP-MS). Human consumption risks were assessed by comparisons to Brazilian and international legislations. No significant differences between sex were observed for all analyzed elements. Even when analyzing only the adductor muscle, all mussel samples exceeded the Brazilian limit for Cr, while 12 samples exceeded the limit for Se. When compared to other regulatory agencies, As and Zn levels were higher than the limits set by China, New Zealand, and the USA. Estimated daily dietary intake values were not above limits imposed by the Food and Agriculture Organization of the United Nations/World Health Organization for any of the assessed elements, although it is important to note that only the adductor muscle was assessed. Therefore, continuous metal and metalloid monitoring in bivalves in the study region is suggested, as metal transport and bioavailability, especially in coastal estuaries such as Guanabara Bay, which are currently undergoing significant changes due to anthropogenic activities.


Asunto(s)
Perna , Contaminantes Químicos del Agua , Animales , Brasil , Monitoreo del Ambiente , Estuarios , Humanos , Contaminantes Químicos del Agua/análisis
3.
Environ Pollut ; 292(Pt A): 118360, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34653584

RESUMEN

Muscle melanisation in sand flathead is visible as black spots in the normally white flesh of fish. It is widespread in Tasmania, including at the Tamar Estuary, with increasing frequency of reporting by recreational fishers. The phenomenon is more prevalent in areas impacted by heavy metal pollution and has been linked to heavy metal accumulation. In this study, image processing software ImageJ was employed to study the phenomenon and to establish an objective rating system. A longitudinal profile plot was used to study the greying of the fillet. The degree of melanisation was rated based on the percentage surface area melanised on the surface and in transverse sections of fillets. A muscle melanisation scoring system for sand flathead was established based on visual interpretation using the macroscopic melanisation scoring criteria: melanisation scores 0 = <0.5%, 1 = 0.5-5%, 2 = 5-20%, and 3 = >20% (% = melanised surface area in proportion to the whole fillet). A refined image analysis technique was developed to quantify the percentage of melanised muscle surface area and the muscle melanisation scoring system was statistically validated. Sand flathead fillet with higher melanisation score was shown to be linked to increased intensity of greyness and greater numbers and size of black spots on the surface of fillets and within the flesh. The greying and black spots were primarily concentrated at the anterior region of fillet and around the dorsal vertebrae zone on transverse section of fillets. Overall, findings from this study established the use of image analysis techniques to validate visual inspection and to give a standardised and objective method to determine the degree of melanisation in sand flathead. As muscle melanisation appears to be linked to heavy metal pollution, the standardised scoring system would facilitate future research for environmental pollution and monitoring purposes.


Asunto(s)
Perciformes , Contaminantes Químicos del Agua , Animales , Estuarios , Peces , Músculos/química , Contaminantes Químicos del Agua/análisis
4.
J Environ Manage ; 301: 113576, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34597946

RESUMEN

The approach of applying stressor load limits or thresholds to aid estuarine management is being explored in many global case studies. However, there is growing concern regarding the influence of multiple stressors and their cumulative effects on the functioning of estuarine ecosystems due to the considerable uncertainty around stressor interactions. Recognising that empirical data limitations hinder parameterisation of detailed models of estuarine ecosystem responses to multiple stressors (suspended sediment, sediment mud and metal content, and nitrogen inputs), an expert driven Bayesian network (BN) was developed and validated. Overall, trends in estuarine condition predicted by the BN model were well supported by field observations, including results that were markedly higher than random (71-84% concordance), providing confidence in the overall model dynamics. The general BN framework was then applied to a case study estuary to demonstrate the model's utility for informing management decisions. Results indicated that reductions in suspended sediment loading were likely to result in improvements in estuarine condition, which was further improved by reductions in sediment mud and metal content, with an increased likelihood of high abundance of ecological communities relative to baseline conditions. Notably, reductions in suspended sediment were also associated with an increased probability of high nuisance macroalgae and phytoplankton if nutrient loading was not also reduced (associated with increased water column light penetration). Our results highlight that if stressor limit setting is to be implemented, limits must incorporate ecosystem responses to cumulative stressors, consider the present and desired future condition of the estuary of interest, and account for the likelihood of unexpected ecological outcomes regardless of whether the experts (or empirical data) suggest a threshold has or has not been triggered.


Asunto(s)
Ecosistema , Estuarios , Teorema de Bayes , Nitrógeno , Fitoplancton
5.
Sci Total Environ ; 803: 149972, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-34482142

RESUMEN

The present study assesses the spatial distribution and temporal trends of the water dissolved phase (WDP), suspended particulate matter (SPM) and sediment partitioning of atrazine (ATR) and its metabolites in the Volturno River estuary. The load contribution of ATR and its metabolites in this river to the Central Mediterranean Sea was estimated. Samples were collected in 10 sampling sites during the four seasons. The total concentrations of ATR and DPs detected ranged from 18.1 to 105.5 ng L-1 in WDP, from 4.5 to 63.2 ng L-1 in SPM, and from 4.6 to 18.6 ng g-1 in sediment samples, indicating high levels of these pollutants. Structural equation model and the ratio study indicated that the relationship between sediment and WDP pollutants occurred through the SPM. The pollutants load at the Volturno River in its mouth was evaluated in about 30.4 kg year-1, showing that this river is an important source of these analytes through discharge into Central Mediterranean Sea. Principal component analysis indicated that ATR and its metabolites pollution moves from Volturno River mouth southward and increased in the rainy season. The desethylatrazine-to-atrazine ratio was higher than 0.5 for all samples analyzed, indicating an historical discharge and a long residence time of ATR in sediment about two decades after its ban, and classifying ATR as a nonpoint source contaminant. This study makes up the first record of ATR and its metabolites in superficial water of Southern Italy and provides helpful data as starting point for future studies.


Asunto(s)
Atrazina , Contaminantes Químicos del Agua , Atrazina/análisis , China , Monitoreo del Ambiente , Estuarios , Sedimentos Geológicos , Ríos , Contaminantes Químicos del Agua/análisis
6.
Sci Total Environ ; 803: 150111, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-34525698

RESUMEN

Two scenarios were selected to simulate the situation before the closure of the Three Gorges Dam (TGD) in 1996 (Scenario 1) and after the completion of the Three Gorges Project in 2010 (Scenario 2). A modified polar co-ordinated segmented quantification method was proposed to quantify the heavy metal footprint excursion in Scenarios 1 and 2 and further evaluate their influence on the six sensitive targets in the Yangtze Estuary. Scenario 3 was utilised to analyse the negative effects of the footprint range on the spatio-temporal overlap of the Chinese sturgeon juveniles arriving in the estuarine reserve, set in the TGD-altered biological rhythm. Each scenario comprises four simulation sites from March to September, including three major urban sewage outlets, named Bailonggang (BLG), Zhuyuan (ZY), Shidongkou (SDK), and the upstream pollution source, represented by Xuliujing (XLJ). The results showed that the increased discharge in the dry season moved the post-TGD footprint further away from Chongming Island. Additionally, the outward side footprint was formed during the flood season, when the average discharge was lower than that during the pre-TGD period, being 'pushed' to the northwest by the monsoon and Taiwan warm current, resulting in a narrowing of the overall extent. The TGD positively impacted the XLJ and BLG simulation sites, given their shrinking footprint range and the decreasing trajectories of intruding sensitive targets in Scenario 2, in contrast to SDK and ZY.


Asunto(s)
Estuarios , Metales Pesados , China , Monitoreo del Ambiente , Metales Pesados/análisis , Ríos , Estaciones del Año
7.
Sci Total Environ ; 805: 150261, 2022 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-34536859

RESUMEN

We assessed the importance of boulder reefs to the oxygen dynamics of a shallow estuary during two growing seasons in 2017 and 2018. Using open-system diel oxygen measurements and benthic and pelagic incubations, we evaluated the relative contribution of pelagic and benthic habitats to the ecosystem metabolism along a depth gradient in two areas, with (Reef) and without (Bare) boulder reefs in the Limfjorden, Denmark. System integrated areal rates of gross primary production (GPP) and ecosystem respiration (ER) both increased with depth in both areas. Benthic contribution to system GPP and ER was highest at shallow depth where it represented 47 and 53% respectively. However, with increasing depth pelagic processes dominated GPP and ER (98 and 94%) even in the Reef area. Although the Reef area had higher biomass of auto- and heterotrophic organisms (macroalgae and macrofauna), benthic GPP was at similar level in both areas, due to a significant contribution from micro-phytobenthic organisms. The Reef area had lower sediment pools of organic matter, nitrogen and phosphorous and was slightly more oxygenated compared to the nearby Bare area. Extreme temperatures and higher levels of nutrients in 2018 caused a marked increase in benthic ER rates resulting in net heterotrophy (NEM = GPP - ER < 0) in 2018 compared to net autotrophy (NEM > 0) in 2017. Under current eutrophic conditions, boulder reefs do not contribute positively to the oxygen dynamics in the estuary. Reoccurring blooms of phytoplankton with high organic matter decomposition combined with high temperatures and dominance of fauna stimulate depletion of oxygen around the reefs. Significant improvements in water clarity are needed to regrow perennial macroalgae and induce net autotrophy. Under current turbid conditions, it is only recommended to establish boulder reefs in shallow (<3 m) parts of the estuary.


Asunto(s)
Ecosistema , Estuarios , Biomasa , Arrecifes de Coral , Oxígeno/análisis , Fitoplancton
8.
Sci Total Environ ; 805: 150381, 2022 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-34818786

RESUMEN

Suspended sediments in the estuary play an important role in regulating the erosion-accretion and shaping the geomorphological patterns. Yet, it can be strongly impacted by the human activities. Constructions of basin and estuarine engineering in the Yangtze River Estuary (YRE), including constructions of Three Gorges Dam (TGD) further upstream of the Yangtze River and Deep Waterway Project (DWP) in the estuary, have greatly modified the distribution of estuarine suspended sediment concentration (SSC). In this study, we retrieved the surface water SSC in the YRE from a total of 149 Landsat-TM/ETM+/OLI images (from 1984 to 2020) and 515 GOCI images (from 2011 to 2020) to obtain its long-term dynamics. The results indicate that the SSC estimation model performed well with a mean absolute percentage error of 12.83% and a root mean square error of 0.027 g/L. The SSC in the YRE demonstrated an overall declining pattern over the past 37 years, particularly during the flood season, which was related to the decrease in the sediment discharge of Yangtze River. The SSC in different sub-regions across the entire YRE responded differently to the reduced sediment discharge caused by the impoundment of the TGD. The SSC in the inner estuary responded promptly with a 40.3% decline noted immediately after the impoundment of the TGD, whereas hysteresis of SSC changes was found in the estuarine turbidity maximum zone (TMZ) and have begun to decline by 20.0-30.0% in the recent 5 years. Constructions of local estuarine engineering, such as the DWP also exert important controls on the estuarine SSC dynamics by blocking the lateral transport of suspended sediments between the shoal and the river channel. Our results highlight the strong influence of engineering constructions on the SSC dynamics in the world large river-influenced estuaries.


Asunto(s)
Estuarios , Contaminantes Químicos del Agua , China , Monitoreo del Ambiente , Sedimentos Geológicos , Humanos , Ríos , Contaminantes Químicos del Agua/análisis
9.
Chemosphere ; 287(Pt 3): 132206, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34560496

RESUMEN

The flux of terrestrial dissolved inorganic phosphorous (DIP, i.e. PO43-) via rivers into coastal seas is usually calculated by simply multiplying its concentration with the corresponding water flow at the river mouth. Subsequent adsorption/desorption of DIP onto suspended sediment and the influence of salinity in the estuary are often overlooked. A series of DIP adsorption/desorption experiments under different salinities (0, 5, 15, 30) and suspended sediment concentrations (1-40 g L-1) were conducted in order to assess the potential influence of these factors on the overall DIP loading to the coastal zone. The effect of different sea-salt ions on DIP adsorption/desorption was also assessed by comparing different experimental solutions (NaCl solution, artificial seawater and real seawater). In estuaries, the adsorption of DIP to suspended sediments was greater than desorption, and the net adsorption increased with increasing concentration of suspended sediments and salinity. This enhanced DIP adsorption onto suspended sediment reduces the riverine discharge of DIP to coastal ecosystems. Disregarding this process, especially for the gated estuaries with high sediment resuspension, potentially leads to an overestimation of the terrestrial DIP input to the coastal region.


Asunto(s)
Ríos , Contaminantes Químicos del Agua , Adsorción , Ecosistema , Monitoreo del Ambiente , Estuarios , Sedimentos Geológicos , Fósforo/análisis , Contaminantes Químicos del Agua/análisis
10.
Biol Trace Elem Res ; 200(1): 385-401, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33590454

RESUMEN

Filter-feeder bivalves such as non-indigenous Ruditapes philippinarum absorb and accumulate metals, resulting in multi-element profiles. The goal of this study was to analyse spatial and temporal distributions of the multi-element signatures in R. philippinarum populations of the Tagus and Sado estuaries (SW coast, Portugal). The clam and sediment samples were collected at three sampling sites in each estuary, on three sampling occasions, and the analysis were done by ICP-MS (inductively coupled plasma mass spectrometry). The chemical elements were categorized according to estuarine geomorphology sources (Se, Co, Ni and Cu), elements with function in metabolic processes of the clams (Mn, Fe, Zn and Cr) and elements derived from the anthropogenic inputs (As, Pb and Cd). Zinc, Co, Ni and Pb were the main contributors for the chemical signatures of Tagus estuary populations, whilst for the Sado estuary populations were Cu, Fe, Cr, As and Cd. They were representative of all elemental categories and proved to be spatial and temporal habitat discriminators of bivalves' estuarine populations. The multi-element signatures of R. philippinarum as a natural tag derived from the physical and chemical conditions of its habitat is a potential rapid tool to use in ecological monitoring and habitat assessment.


Asunto(s)
Bivalvos , Metales Pesados , Contaminantes Químicos del Agua , Animales , Monitoreo del Ambiente , Estuarios , Sedimentos Geológicos , Metales Pesados/análisis , Contaminantes Químicos del Agua/análisis
11.
Sci Total Environ ; 805: 150193, 2022 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-34543799

RESUMEN

The concentration of dissolved CH4 and N2O, as well as the partial pressure of CO2 (pCO2) were studied in the Guadalquivir estuary. Samples were taken in March and April 2018 and 2019, under different rainy and tidal conditions. The available database for summer 2017 (Sierra et al., 2020) was included in the interpretation of the factors that determine the variability of these gases in the Guadalquivir estuary. Two different types of samplings were carried out: a longitudinal transect across the river with salinity values close to zero and another one during two consecutive tidal cycles in the mouth of the estuary. The highest concentrations were found in the upper zone of the estuary and during the low tide. This distribution was related to 4 factors: temperature, salinity, exchange with the atmosphere, and biochemical processes together with the river inputs. Temperature is one of the factors that clearly seems to determine the distribution of gases and fluxes, showing the highest values in the upper zone during the summer of 2017. Intense rains cause a dilution effect of the gas in the water column, this provoked, during the season of spring 2018, an increase in the salinity factor in the distribution of gases in the middle zone. High concentrations of the gases have been linked to production processes in the water column, as well as to benthic production and lateral inputs. While the gases concentrations at the mouth presented values close to those of the equilibrium with the atmosphere, the fluxes in the upper zone of the estuary reached average values of 89.6 mmol m-2 d-1, 121.7 µmol m-2 d-1 and 59.9 µmol m-2 d-1 for CO2, CH4 and N2O, respectively. Generally, water-atmosphere fluxes are positive through the whole study, which means that the estuary acts as a source of these gasses to the atmosphere.


Asunto(s)
Dióxido de Carbono , Estuarios , Dióxido de Carbono/análisis , China , Monitoreo del Ambiente , Metano/análisis , Óxido Nitroso/análisis , Estaciones del Año
12.
Environ Monit Assess ; 193(12): 767, 2021 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-34731306

RESUMEN

The sediment contamination by trace metals in coastal aquatic ecosystems is a worldwide environmental problem, since metals can be toxic, persistent, and bioaccumulated. In case of natural events, such as storms, or anthropogenic activities, like dredging, the sediment resuspension to the water column occurs and can solubilize metals, probably increasing their bioavailability and consequently the risk to aquatic life. This study evaluated the bioavailability on reactive trace metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in estuarine sediments from Iguaçu and Meriti Rivers, both in the drainage basin of Guanabara Bay (Rio de Janeiro, Brazil). Additionally, a discussion about the anthropogenic interference throughout time of six short sediments cores, calculating three different indexes (contamination factors, CF; potential ecological risk index for a single heavy metal, Eif for short; potential ecological risk, PERI) was performed. It was considered as reactive phase, the metal concentrations obtained using a weak acid extraction (in HCl 1 mol L-1 solution). Zn presented high concentrations after resuspension, being above effect range medium (ERM) (52.81 to 1337.4 mg kg-1). The CF indicated very high contamination degree for Cu (14.62 to 17.96) and Zn (27.80 to 35.85) for both rivers. The Eif for short presented higher risk to Cu and Zn for Iguaçu and Meriti rivers. PERI index classified Meriti River samples as severely contaminated (238.10 to 351.62).


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , Brasil , China , Ecosistema , Monitoreo del Ambiente , Estuarios , Sedimentos Geológicos , Metales Pesados/análisis , Medición de Riesgo , Ríos , Contaminantes Químicos del Agua/análisis
13.
Artículo en Inglés | MEDLINE | ID: mdl-34770154

RESUMEN

Understanding and assessing ecological vulnerability for estuarine islands are important for maintaining estuarine island ecosystem services and its sustainable development. However, due to its complex fresh water-sea-land interaction mechanism and multiple stressors from both climate change and anthropogenic influence, a comprehensive evaluation of ecological vulnerability for estuarine islands has been limited. Therefore, taking the typical estuary island of Chongming Island as an example, we developed a comprehensive evaluation system of ecological vulnerability for an estuarine island ecosystem based on the pressure-state-response (PSR) conceptual model, and explored the spatial and temporal distribution of ecological vulnerability in 2005 and 2015. The results indicated that the main pressures of Chongming Island from saltwater intrusion intensity and land use intensity were mainly distributed in northern coastal areas and eastern areas of wetland; the ecological vulnerability index (EV) of Chongming Island showed a slight decrease from 2005 to 2015; and three categories of towns based on ecological vulnerability assessment for an eco-island planning and environmental management were identified. Our study provides an effective evaluation system of ecological vulnerability for estuarine islands, which could be helpful for planners and decision makers in improving eco-island planning and environmental management.


Asunto(s)
Ecosistema , Ríos , China , Cambio Climático , Conservación de los Recursos Naturales , Estuarios , Humedales
14.
Environ Monit Assess ; 193(12): 804, 2021 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-34779929

RESUMEN

In temperate estuaries of the southern Gulf of St. Lawrence, intermittent seasonal anoxia coupled with phytoplankton blooms is a regular occurrence in watersheds dominated by agricultural land use. To examine the spatial relationship between dissolved oxygen and phytoplankton throughout the estuary to assist in designing monitoring programs, oxygen depth profiles and chlorophyll measurements were taken bi-weekly from May to December in 18 estuaries. In five of those estuaries, dissolved oxygen data loggers were set to measure oxygen at hourly intervals and at multiple locations within the estuary the subsequent year. The primary hypothesis was that dissolved oxygen in the upper estuary (first 10% of estuary area) is predictive of dissolved oxygen mid-estuary (50% of estuary area). The second hypothesis was that hypoxia/superoxia in the estuary is influenced by temperature and tidal flushing. Oxygen depth profiles conducted in the first year of study provided preliminary support that dissolved oxygen in the upper estuary was related to dissolved oxygen throughout the estuary. However, dissolved oxygen from loggers deployed at 10% and 50% of estuary area did not show as strong a correlation as expected (less than half the variance explained). The strength of the correlation declined towards the end of summer. Spatial decoupling of oxygen within the estuary suggested influence of local conditions. Chlorophyll concentration seemed also to be dependent on local conditions as it appeared to be coupled with the presence of sustained anoxia in the upper estuary with blooms typically occurring within 7 to 14 days of anoxia. The practical implication for oxygen monitoring is that one location within the most severely impacted part of the estuary is not sufficient to fully evaluate the severity of eutrophication effects.


Asunto(s)
Estuarios , Oxígeno , Monitoreo del Ambiente , Eutrofización , Nutrientes , Oxígeno/análisis , Estaciones del Año
15.
An Acad Bras Cienc ; 93(suppl 3): e20200219, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34787168

RESUMEN

The horizontal distribution of plankton communities in a subtropical mixed estuarine system over one tidal cycle was investigated. Hydrological and planktonic samples were obtained twice on 17 July 2007 in a transect with ten stations in the Babitonga Bay estuary, south Brazil (~26°S). Hydrological variables did not vary spatially or tidally during samplings. However, in the cluster analyses both phyto and zooplankton were structured according to their estuarine position and in the inner stations also by the tidal condition. Phytoplankton abundances were higher during flood tide in the inner estuary (max. 122,583 ind.L-1), where diatoms dominated, particularly Diploneis bombus. However, the density at ebb tide increased towards outer estuary (max. >100,000 ind.L-1) and flagellates, mostly Gymnodinium spp., became abundant. Zooplankton abundances were higher at intermediate stations during both tides (max. 13,691 ind.m-3). The innermost stations were dominated by the copepod Acartia tonsa, while in the outermost stations Temora turbinata and the polychaete larvae Loimia sp. dominated. The results demonstrate how variable the estuarine plankton horizontal structure can be over short time-scales even in mixed estuarine systems under relatively homogeneous conditions, highlighting the importance to consider such temporal scales for a more accurate understanding of the dynamics of these communities.


Asunto(s)
Copépodos , Plancton , Animales , Estuarios , Fitoplancton , Zooplancton
16.
Zootaxa ; 5057(1): 29-51, 2021 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-34811224

RESUMEN

A new genus, Arktourella gen. nov., is proposed to accommodate a new member of the harpacticoid family Normanellidae, A. margarethae gen. et sp. nov., from a polluted estuary in north-western Mexico. The new genus was attributed to the laophontoidean family Normanellidae on account of the lack of outer spinous processes on the second antennulary segment, one abexopodal seta on the antennary allobasis, four setae on the one-segmented antennary exopod, endopod of first swimming leg two-segmented with first segment elongated and with two distal elements on second segment, endopods of second to fourth legs two-segmented, distal setae on the male second endopodal segment of second and third legs reduced, and outer spine of the male second endopodal segment of third leg fused to segment. The new, so far monotypic genus, differs from the other normanellid genera in the presence of four elements on the third exopodal segment of the first leg, and two outer spines on the third exopodal segment of second to fourth legs. No synapomorphies were observed for Arktourella gen. nov. and Normanella, but they are unique within the Normanellidae in that the mandibular basis and endopod are not fused. Maximum parsimony analysis and Bayesian inference using 59 morphological characters to assess the relationships between the genera of the family Normanellidae confirmed the affinity of Arktourella gen. nov. and Normanella, and their sister group relationship with Sagamiella. Paranaiara and Pseudocletodes were shown consistently to be closely related and are the sister taxa of Normanella-Arktourella gen. nov.-Sagamiella. Arktourella gen. nov., Paranaiara and Pseudocletodes share the presence of a large spinulose spine on the fifth and sixth segments of the female antennule, but its significance is not clear. Additionally, we propose a key to the genera of the Normanellidae.


Asunto(s)
Copépodos , Estructuras Animales , Animales , Teorema de Bayes , Estuarios , Femenino , Masculino , Natación
17.
Zootaxa ; 5052(3): 353-379, 2021 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-34810868

RESUMEN

Here, we describe four new species of Crellidae Dendy, 1922 and discuss characters and relationships from published molecular phylogenies including crellid sponges. New species proposed are Crella (Pytheas) chiloensis Fernandez, Gastaldi, Pardo Hajdu, sp. nov., from southern Chile (15 m depth), C. (P.) desventuradae Fernandez, Gastaldi, Zapata-Herndez Hajdu, sp. nov., from Desventuradas Archipelago (1020 m depth), Crella (P.) santacruzae Fernandez, Gastaldi, Thompson Hajdu, sp. nov., from deep waters off Argentina (750 m depth) and Crellomima sigmatifera Fernandez, Gastaldi Hajdu, sp. nov., from the Chilean fjords region (ca. 20 m depth). These new species are set apart from each other and from known species mainly due to aspects of their spiculation. Chelae microscleres and acanthostyles supply characters that might be used to infer phylogenetic relationships and to verify the monophyly of Crella Gray, 1867 and Crellidae, which has seemingly been contradicted by preliminary molecular data available in the systematics literature. Our own interpretation of phylogenetic affinities, in the light of morphological characters from previous taxonomic studies, argues for a classification reassessment of materials (vouchers) included in these molecular phylogenies, especially in the case of Crella incrustans (Carter, 1885). We argue that currently available molecular phylogenetic outcomes for crellid sponges are not supportive of the polyphyly of Crella and Crellidae.


Asunto(s)
Estuarios , Poríferos , Animales , Chile , Filogenia
18.
Zootaxa ; 5051(1): 506-528, 2021 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-34810893

RESUMEN

Both sexes of a new brackish-water species, Nannopus sinusalbi sp. nov. (Nannopodidae) are described from the Baha Blanca estuary (3853S, 6207W) in Buenos Aires Province, Argentina. The only previous record of the genus in the study area was identified as the type species, Nannopus palustris Brady, 1880, with no description or illustrations, hence its authenticity cannot be confirmed. Nannopus brasiliensis Jakobi, 1956 is relegated to species inquirenda in the genus rather than being considered a junior synonym of the type species. Nomenclatural issues related to the usage of the alternative spellings Iliophilus Lilljeborg, 1902 and Ilyophilus sensu Sars (1909) and the unavailability of Ilyophilus canui Kim, Choi Yoon, 2017 are discussed. An updated key to the 18 identifiable species of Nannopus (excluding the type species N. palustris) is presented. The harpacticoid assemblage at the type locality showed a distinct seasonality with N. sinusalbi sp. nov. representing about 8% of the community. The new species showed densities below 5ind.cm­2 during most of the year, reaching an abrupt peak of 40.17ind.cm­2 towards the end of the summer, when the maximum proportion of ovigerous females was recorded.


Asunto(s)
Copépodos , Animales , Estuarios , Femenino , Masculino
19.
Artículo en Inglés | MEDLINE | ID: mdl-34639319

RESUMEN

The accumulation of dissolved inorganic nitrogen (DIN) in estuaries has become a global environmental problem. A two-dimensional, hydrodynamic water quality model was constructed in this study to investigate the sources of DIN pollution in the Minjiang Estuary. The concentration response field between the stream input and DIN in the estuary was established by using the surveyed source data of the study area. A sharing coefficient method was used to calculate the contribution percentage of each outfall to derive and propose a reasonable nitrogen reduction plan. The results showed that the input of land-based nitrogen into the Minjiang River contributed more than half of the DIN in the near-shore sea; the middle and upper reaches of the Minjiang River largely influenced the estuary area (38.57%). Conversely, the estuary and the coastline accounted for a smaller proportion of only 5.24%, indicating that an integrated DIN reduction should be implemented in the estuary area of the whole river basin. The model calculations showed that the reduction results, after remediation according to the current national standards for wastewater discharge in rivers, were not satisfactory. Thus, a new scheme is proposed in this paper-the total nitrogen (TN) input from land-based sources into the Minjiang Estuary and from the Shuikou Dam to the Min'an section should be reduced to below 31.64%; simultaneously, the DIN concentration discharged from the Shuikou Dam should be controlled and maintained below 0.5 mg·L-1 (TN = 0.8 mg·L-1). These results will provide guidelines for developing strategies for the improvement of DIN and water quality in similar estuaries.


Asunto(s)
Estuarios , Nitrógeno , China , Monitoreo del Ambiente , Nitrógeno/análisis , Ríos
20.
Sci Total Environ ; 781: 146691, 2021 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-34594059

RESUMEN

Levels of total mercury were measured in tissue of six species of migratory fish (alewife, American shad, blueback herring, rainbow smelt, striped bass, and sea lamprey), and in roe of American shad for two consecutive years collected from the Penobscot River or its estuary. The resultant mercury levels were compared to reference doses as established in the U.S. Environmental Protection Agency (EPA) Integrated Risk Information System and wildlife values. Mercury concentrations ranged from 4 µg/kg ww in roe to 1040 µg/kg ww in sea lamprey. Sea lamprey contained the highest amounts of mercury for both seasons of sampling. Current health advisories are set at sufficient levels to protect fishers from harmful consumption of the fish for mercury alone, except for sea lamprey. Based upon published wildlife values for mink, otter, and eagle, consumption of rainbow smelt, striped bass, or sea lamprey poses a risk to mink; striped bass and sea lamprey to otter; and sea lamprey to eagle. For future consideration, the resultant data may serve as a reference point for both human health and wildlife risk assessments for the consumption of anadromous fish. U.S. EPA works with federally recognized Tribes across the nation greatly impacted by restrictions on sustenance fishing, to develop culturally sensitive risk assessments.


Asunto(s)
Mercurio , Contaminantes Químicos del Agua , Animales , Monitoreo del Ambiente , Estuarios , Peces , Humanos , Maine , Mercurio/análisis , Ríos , Contaminantes Químicos del Agua/análisis
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