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The Salada coastal lagoon is located in Veracruz (Mexico) near the Laguna Verde Nuclear Power Plant (LVNPP). Currently, the lagoon receives the cooling waters used in the LVNPP. To evaluate the fluxes and mobilization of trace elements due to human activities in the area, two sediment cores from the coastal flood plains of Salada Lagoon were analysed. Cores were collected using PVC tubes. Sediments cores were analysed every centimetre for dating ( 210 Pb by alpha detector) and trace metal analysis using ICP-Mass Spectrometry. The dating of both sediment cores covers the period from 1900 to 2013, which includes the construction of the LVNPP (1970's). The Normalized Enrichment Factor shows enrichment of Ag, As and Cr in both sediment cores. These enrichments correspond to the extent of mining activity (which reached a maximum in the 1900's) and to the geological setting of the coastal zone. The profiles of the element fluxes in both sediment cores reflected the construction and operation of the LVNPP; however, the elements content did not show evidence of pollution coming from the LVNPP. [ABSTRACT FROM AUTHOR]

The Marano-Grado Lagoon (MGL) is extensively contaminated by mercury (Hg) from local sources and long-term (500 years) tidally delivered inputs from the Idrija Hg mine (Slovenia) through Isonzo River suspended loads. A multibox WASP-7 (Water Analysis Simulation Program) model was used to simulate the long-term dynamics of the mercury cycle in the MGL. Scenario simulations were used to compute changes in the system over 100 years. Present and future Hg concentrations in water, sediment, and Hg budgets were compared, including evasion and MeHg inputs to the Mediterranean Sea, based on climate changes and mercury capping in tributary rivers. Using the Ref baseline scenario, the model computes a general decrease in Hg T of 13% in the water column and of 80% in sediment and a strong MeHg increase in sediment (+73%). The net sea export of Hg T decreases by 57% to up to 48 kg/y while MeHg increases by 10% to up to 0.63 kg/y. The lagoon sediment recovery time of Hg T up to a target level of 0.3 mg/kg is computed over 570 years for surface sediments (1750 for subsurface sediments). When removing Hg from boundaries, the same target value for surface sediments is reached within 110 years. [ABSTRACT FROM AUTHOR]

Meiofauna are ubiquitous but poorly-studied components of soft-bottom marine habitats around the world, including mangroves. The dynamic environmental conditions and heterogeneous sediments of mangroves present challenges to understanding the structure of mangrove meiofaunal assemblages at various spatial and temporal scales. In this study, we investigated the meiofaunal assemblage structure of sediments colonised by three mangrove species, namely, Avicennia marina, Rhizophora stylosa and Aegiceras corniculatum , at three locations in subtropical eastern Australia. Spatial and temporal variations were tested by sampling at the three mangrove locations (i.e. Tallebudgera, Currumbin and Terranora) in autumn, with samplings repeated at Tallebudgera at two other times broadly representing during dry/cool winter and wet/hot summer seasons. We examined the variability of the sediment environments within each of the different mangrove species, and investigated how meiofaunal assemblages would respond to the particular changes in their habitats to result in differences in assemblage structure between and within sites. Total meiofaunal density was highest in Tallebudgera and Currumbin and lowest in Terranora (mean density of 424, 393 and 239 ind.10 cm −2 , respectively). In Tallebudgera, the density was higher in winter and summer (mean density of 546 and 530 ind.10 cm −2 , respectively). The meiofaunal assemblage in this study shows a trend and association with the environmental variables. High availability of food proxies such phaeopigments, Chl a or TOC, with moderate tannin content and appropriate habitat structure (sediment particle size, belowground root biomass and/or moisture content provide the best condition for the meiofauna to achieve the highest density. However, given the complex dynamic habitats and the spatial heterogeneity of the mangrove environments across different locations and seasons, no clear generalization could be made regarding the key environmental variables that predominantly shape the meiofaunal assemblages’ structure. [ABSTRACT FROM AUTHOR]

The majority of Scotland's saline lagoons are located on the low-lying coastlines of the Western Isles and the northern archipelagos of Orkney and Shetland, where recorded annual relative sea level rise rates are among the highest in Scotland. The sediment-impounded lagoons of Orkney and Shetland will either lose their impoundment and become incorporated in marine coastal waters, or become increasingly saline, as relative sea levels rise. The rock-basin lagoons of the Western Isles will retain their restricted exchange with the sea but will also become more saline with rising sea level. Specialist lagoonal organisms tend to have wide salinity tolerances but may succumb to competition from marine counterparts. In all areas, there are sufficient fresh-water inland water bodies with potential to be captured as lagoons to compensate for loss of extent and number, but the specialist lagoon biota tend to have limited dispersal powers. It is thus possible that they will be unable to transfer to their analogue sites before existing lagoons become fully marine, giving conservation managers the problem of deciding on management options: leave natural processes to operate without interference, manage the saline inflow to maintain the current salinity regime, or translocate lagoon organisms perceived as threatened by rising salinities. Timing of conversion and capture is unpredictable due to local topography and complications caused by variable stratification. [ABSTRACT FROM AUTHOR]

Mangrove rehabilitation programs received much attention in the past decades as a response to widespread global degradation. While the documented successes and failures of mangrove rehabilitation accomplishments were varied, the objective and scheme is common, mainly focused on planting and creating monospecific plantations. This study assessed the structural development and complexity of the large-scale plantations in the central part of Philippines and compared it with the adjacent natural stand as reference. Our study showed that planted forest in both sites had lower structural complexity than the reference natural forest. Between sites, secondary succession in the monospecific plantation in Banacon Island was inhibited as reflected by low regeneration potential, whereas recruitment and colonization of non-planted species was promoted in Olango Island. Even 60 years after the forest was created in Banacon Island, it still lacked the understory of young cohorts which together comprise the regeneration potential that can supposedly add to the structural complexity. Although a potential seed source from adjacent natural forest is available, recruitment and colonization of non-planted species did not progress. MDS analysis of tree density data showed clustering of planted forest from the natural stand. The average SIMPER dissimilarity was 79.9% and the species with highest contributions were R. stylosa (74.6%), S. alba (11.1%) and A. marina (10.6%). Within the natural forest, the same species had the highest dissimilarity contribution, whereas in the planted forest, only R. stylosa contributed the highest dissimilarity. The same trend was also revealed in the MDS ordination analysis of diameter at breast height (DBH). A one-way ANOSIM permutation test of the density and DBH showed a significant difference between the planted and natural forests. Thus, as part of silviculture management intervention, the current practices of mangrove reforestation needs to be reviewed and evaluated to determine the trajectories of its conservation objectives to achieve the best outcome and functionality of the restored habitat. [ABSTRACT FROM AUTHOR]

Abstract: There is widespread interest in the conservation of native Artemia biodiversity. In Portugal, only two known populations of native Artemia remain: one in the Rio Maior salina, the other in the Aveiro salina complex, both of the diploid Artemia parthenogenetica species. All other Portuguese hypersaline environments where Artemia can be found have been invaded by Artemia franciscana, which has eradicated the native strains. Invasiveness and resilience of, respectively, exotic and indigenous species are thought to depend on strain-specific traits and adaptation to local conditions. This work evaluates the reproductive performance of the two Portuguese native strains and the invasive species exposed to different salinities, temperatures, photoperiods and food supplies. Reproduction periods, quantity and quality of offspring varied significantly, depending on both the Artemia strain and environmental conditions. A. parthenogenetica from Rio Maior reproduced better than A. franciscana at high salinity (150) and low food supply, which may reflect an adaptation to its biotope that aids its resistance to invasion. But A. parthenogenetica form Aveiro performed much worse than its invasive competitor, under most of the conditions tested. It is unlikely that A. franciscana has not been introduced in this salina by chance alone. Other biological traits of the local A. parthenogenetica or adaptation to unstudied local factors (e.g. pollution) are probably responsible for this strain's survival. Further knowledge on specific local conditions and trait-specific tolerances to biotic and abiotic conditions are needed to understand (non-)invasion patterns and preserve the remaining native populations. [Copyright &y& Elsevier]

Abstract: Statistical models are key for estimating fish distributions based on environmental variables, and validation is generally advocated as indispensable but seldom applied. Generalized Linear Models were applied to distributions of juvenile Solea solea, Solea senegalensis, Platichthys flesus and Dicentrarchus labrax in response to environmental variables throughout Portuguese estuaries. Species-specific Delta models with two sub-models were used: Binomial (presence/absence); Gamma (density when present). Models were fitted and tested on separate data sets to estimate the accuracy and robustness of predictions. Temperature, salinity and mud content in sediment were included in most models for presence/absence; salinity and depth in most models for density (when present). In Binomial models (presence/absence), goodness-of-fit, accuracy and robustness varied concurrently among species, and fair to high accuracy and robustness were attained for all species, in models with poor to high goodness-of-fit. But in Gamma models (density when present), goodness-of-fit was not indicative of accuracy and robustness. Only for Platichthys flesus were Gamma and also coupled Delta models (density) accurate and robust, despite some moderate bias and inconsistency in predicted density. The accuracy and robustness of final density estimations were defined by the accuracy and robustness of the estimations of presence/absence and density (when present) provided by the sub-models. The mismatches between goodness-of-fit, accuracy and robustness of positive density models, as well as the difference in performance of presence/absence and density models demonstrated the importance of validation procedures in the evaluation of the value of habitat suitability models as predictive tools. [Copyright &y& Elsevier]

Abstract: We assessed the linkages between environmental variables and the spatio-temporal distribution patterns of larval abundance of coastal fish assemblages within and outside the Medes Islands marine protected area (MPA; NW Mediterranean) to explore possible fisheries effects such as larvae export of the latter. We analyzed small-scale fish larvae distribution of 28 representative taxa from the rocky fish assemblage and combined the former in different groups with the help of cluster analysis. Further we assessed the influence of selected abiotic variables on group and species distributions using Generalized Additive Models (GAM’s). We found a high level of variability in the response of larvae groups and species to environmental variables over the two studied periods (spring and summer); depth and habitat of the adults being the most important factors. In addition, distance to the MPA was found as an important variable in defining the location of larvae of strictly coastal species. Our results provided evidence of larval export of three commercial species affected by the MPA (Epinephelus marginatus, Pagellus erythrinus and Scorpaena porcus). Thus our study contributes to the few empirical assessments of larvae export from MPAs and adds to the understanding of the functioning of MPAs as fisheries management tools. Nevertheless, in the future integrated assessments of fisheries effects of MPAs are required that measure the effect of larvae and biomass export on increased fishing yield while taking into account fishing effort dynamics. [Copyright &y& Elsevier]

Abstract: The relative importance of estuarine nursery areas for species of the genus Diplodus and their relations with several environmental variables was evaluated along the Portuguese coast. Nine estuarine systems were sampled with beam trawl surveys. Species of the genus Diplodus were only present in estuaries south of the Ria de Aveiro (40°38′). A latitudinal gradient of increasing species richness and abundance towards the south was found. Estuarine nurseries of Diplodus vulgaris, Diplodus sargus and Diplodus puntazzo were characterized by mud substrate, lower salinity and lower dissolved oxygen, with the exception of Ria Formosa. Diplodus bellottii was associated with estuaries with large areas and high volumes, the Tejo and the Sado. Diplodus bellottii nursery grounds were characterized by low depth. Diplodus annularis was associated with seagrass and saltmarsh habitats, certainly because it is the only species of the genus Diplodus which recruits exclusively to seagrass meadows. Diplodus annularis nursery grounds were also characterized by sand substrate, higher salinity and higher dissolved oxygen. Niche breath varied widely amongst species and location. Diplodus vulgaris generally presented the highest values of niche breath, except when D. bellottii was present. Niche overlap was not high, the highest value being that between D. vulgaris and D. sargus in the Mira estuary, with 76% spatial niche overlap. Considerations were made on these species progress towards the north in a climate warming context, taking into account the habitat associations described here. [Copyright &y& Elsevier]

Abstract: This paper aims to reveal spatial variation in the abundance of infaunal bivalves and polychaetes at different spatial scales (station: 200–800m intervals; plot: 5–20m), and to reveal environmental variables affecting the spatial distribution of animals in the Natori River estuary, Japan. We found six bivalve species and eight polychaete species from 52 plots at 12 stations. Nuttallia olivacea and Heteromastus sp. were found to be the most abundant species of bivalves and polychaetes, respectively. Assemblage patterns of bivalves and polychaetes were classified into five distinct groups. Substrata (silt-clay contents), salinity, and relative elevation were the variables found to affect the infaunal assemblage patterns. Chlorophyll a was not a significant variable, but benthic animals were absent at sites with extremely low chlorophyll a conditions. Macrobenthic assemblage patterns were different not only between stations but often differed between plots at the same station, reflecting the complex assemblage structure of benthic invertebrates. Detailing such animal–environment relationship is essential in understanding the potential food supply for estuarine fishes. [Copyright &y& Elsevier]

Abstract: The Juan de Fuca Eddy is a seasonal, counter-clockwise gyre off the mouth of the Strait of Juan de Fuca between Washington, USA and British Columbia, Canada that may provide favorable feeding habitat for juvenile coho salmon (Oncorhynchus kisutch) during their early marine existence. In late September 2002, physical and biological sampling was conducted along two transects of the eddy region. Surface rope trawling was conducted to capture juvenile salmon and other nekton, along with bongo and neuston net tows to examine potential mesozooplanktonic salmon prey. Presence of the Juan de Fuca Eddy was confirmed with vertical water profiles. In addition, nutrient and chlorophyll a concentrations collected from 3-m depth were within the range observed in previous studies within the eddy region. In the mesozooplankton community, euphausiids, chaetognaths, and decapod megalopae were common. In the diet of juvenile coho salmon, euphausiids and decapod megalopae were dominant by percent number, and larval and juvenile fish were dominant by percent weight. Feeding intensity (percent body weight) based on stomach contents was variable, but not significantly different among stations. To compare the Juan de Fuca Eddy region with an upwelling area, we sampled along a transect off La Push (LP), Washington, USA which is south of the eddy. The eddy region was found to be less productive than the LP transect. Nutrients were lower, chlorophyll a concentrations were higher, and zooplankton abundance was generally higher along the LP transect than in the eddy region. In addition, more juvenile coho salmon were captured from the LP transect than the eddy region. Prey items in stomachs of salmon from the LP transect were heterogeneous compared to those from the eddy region. Feeding intensity along the LP transect was slightly lower and more variable than in the eddy region, and differences in feeding intensity among LP stations were significant. In addition, feeding intensities among stations nested within regions were significantly different. [Copyright &y& Elsevier]

Abstract: Fish larvae and hydrographic data collected in the Gulf of California (GC) in December 2002 are used to describe larval fish assemblages (LFAs) and to explore their relationships with environmental variables (temperature, salinity, dissolved oxygen, fluorescence maximum, and superficial chlorophyll a). The Bray–Curtis dissimilarity index defined three LFAs, distributed in areas with distinctly different environmental conditions. The affinity of most of the species with the environmental characteristics of their areas of distribution could be interpreted as an indication that spawning occurred inside those areas. Particle tracking in current fields from a 3D numerical model and connectivity matrices are used to assess larval retention in the LFA areas. The technique is well suited for seas like the GC that have well-defined circulation patterns. On time scales around 30days, retention (from 56% to 73% of the particles) occurred (1) for the North LFA in the Upper GC, (2) for the Channel-Center LFA in the anticyclone over the Northern GC and in Ballenas Channel, and (3) for the South LFA in the eddy over San Pedro Mártir basin and in the shallow zone off the peninsula. Therefore, the Lagrangian analysis revealed that the observed LFAs have a permanency long enough to allow fish larvae to remain in a favorable environment until they develop motility. The main particle export path (less than 26% of the particles) was from the North to the South LFA, following the anticyclonic main flow and coinciding with the gradient in species number and larval abundance. [Copyright &y& Elsevier]

Spatio-temporal variability in assemblages of pelagic fish in Chesapeake Bay from 1995 to 2000 was documented based on midwater trawl surveys conducted three times annually (April, July, and October). Numerically dominant pelagic and benthopelagic fishes, 30–256 mm TL, were included in the analysis. Species assemblages, diversity indices, biomass distributions, and a correspondence analysis revealed that physical forcing, primarily driven by freshwater input, shaped the structure of fish communities, both annually and regionally. But, seasonal succession occurred, with adults dominating in the spring and recruited juveniles dominating in the fall. The dominant species were bay anchovy (Anchoa mitchilli), Atlantic croaker (Micropogonias undulatus), white perch (Morone americana), spot (Leiostomus xanthurus), weakfish (Cynoscion regalis), and Atlantic menhaden (Brevoortia tyrannus). Young-of-the-year (YOY) and age-1+ fish were concentrated in different regions and different seasons. A correspondence analysis showed that salinity was the most important environmental factor explaining annual differences in the upbay–downbay gradients in fish community structure. In 1997–2000, following a surge of freshwater input and nutrient loadings in 1996, October baywide fish biomass increased by 120% and mean baywide dissolved oxygen (DO) concentration below the pycnocline in summer decreased by 30%. These interannual variabilities in baywide fish biomass and mean DO suggest a relationship between bay plankton productivity and fish production. Species composition shifted markedly in 1996 when YOY and age-1+ anadromous fishes became dominant, but returned progressively in subsequent years to the usual structure in which bay anchovy and other polyhaline species were dominant. [Copyright &y& Elsevier]

The distribution of epibenthic invertebrate biomass in relation to environmental factors was examined in the St. Lawrence system. Biomass estimates for epibenthos sampled yearly for 9 years on 102 suspended collectors (navigation buoys), were related to environmental data from the literature (surface water temperature, water salinity, water transparency, current velocity, chlorophyll a and primary production) using a weighted multiple linear regression analysis. Regression models were generated for total biomass and the biomass of the single dominant sessile species: Mytilus edulis, Semibalanus balanoides, Balanus crenatus, Obelia longissima and Hiatella arctica. Water temperature and water transparency, as well as some biogeographic groups of buoys represented by dummy variables, collectively explained 90.6% of the variance in total biomass. Water temperature, water transparency, biogeographic groups and, to a lesser degree, primary production, were the variables having a significant influence on the biomass of individual species. The lognormal weighted multiple regression model explained up to 84.5% of the variance in M. edulis biomass data and 67.9, 70.0, 71.6 and 38.9%, respectively, of the variance in S. balanoides, O. longissima, B. crenatus and H. arctica biomass data. The need to consider simultaneous biological and environmental sampling at the relevant temporal and spatial scales to model large marine coastal ecosystems is discussed. [Copyright &y& Elsevier]

Marine coastal areas have high social-economic relevance and ensuring the good quality of these areas has gained importance in the past decades due to the increase of anthropogenic pressures. Understanding the dynamics of these areas is crucial to support management decisions. In this context, phytoplankton communities are generally used as key indicators of environmental quality as they respond in short time-scales and are at the base of food webs. This work intends to improve our understanding on how phytoplankton communities respond to environmental conditions, particularly in upwelling areas. Seawater samples were collected from Algarrobo Bay, Central Chile, for both phytoplankton pigments and microscopy analysis. Data were analyzed in combination with physico-chemical parameters and two distinct hydrographic regions were identified for the study area: i) a region occupying most of the northern bay section, characterized by lower temperatures and dissolved oxygen (DO), higher concentration of nutrients and higher N:P, where a mixed community with diatoms, chrysophytes, cryptophytes, haptophytes and other small flagellates were observed; and ii) a central-southern section, with higher temperatures and DO, lower nutrients and lower N:P, where diatoms, in particular the centric diatom Chaetoceros Ehrenberg, 1844 sp. (~92.5% on average), dominated the phytoplankton assemblage. Other common but much less abundant diatom genus included Skeletonema Greville, 1865, Eucampia Ehrenberg, 1839 , Dactyliosolen Castracane, 1886, Nitzschia Hassall, 1845, Cylindrotheca Rabenhorst, 1859 and Asterionellopsis Round, 1990. Apart from diatoms, the most abundant taxa belonged to flagellates, mainly chrysophytes (228.4 × 103 cells L−1 on average) and cryptophytes (213 × 103 cells L−1 on average). Overall, results suggest that the southern part of the Algarrobo Bay, with higher residence times and nutrient discharges, may act as an upwelling shadow area, where phytoplankton species can accumulate. • Phytoplankton and environmental conditions were evaluated in a coastal bay under upwelling influence. • High phytoplankton biomass and diatom dominance were seen in the southern part of the bay. • Diatoms favored by cold and saline waters and flagellates were linked to the opposite conditions. • Two main regions characterized by distinct phytoplankton communities were found. • A potential zone of both upwelling shadow and anthropogenic impact is identified. [ABSTRACT FROM AUTHOR]