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Within the program "Marine Ecosystems of the Siberian Arctic," based on materials collected during cruises 69 and 72 of the R/V Akademik Mstislav Keldysh, the distribution of chemical elements (As, Ba, Bi, Co, Cr, Cr, Cd, Co, Cu, Cr, Mn, Ni, Pb, Sc, Ti, Tl, Th, V, U, and Zn) and organic carbon in the benthic mass taxa of methane seepage fields in the Laptev Sea and outside of them was examined. For the first time, the bioaccumulation potential (BP) was quantified, taking into account, in addition to the concentrations of elements in organisms, their biomass. On the C-15 methane field, the ophiuroid population accumulates each element per square meter of seafloor up to 40 times greater than at the background station. Ophiuroids and bivalves exhibited elevated BP for Ni, As, Ba, Cu, Ti, V, Mn, and Zn compared to other elements. At the same time, the BP of ophiuroids significantly exceeds that of bivalves. It is suggested that the increased bioaccumulation of some heavy metals and metalloids is related to greater bioavailability of organic matter in the bottom sediments of methane seeps. Organic carbon revealed the highest BP, which was especially pronounced in the C-15 methane field. At the background station, taxa accumulate a significantly smaller (by a factor of 10) amount of carbon in their biomass. As a result of the detritus feeders' activity, bottom sediments are enriched in organic carbon, which indicates an important contribution of benthic organisms to the carbon cycle in the Arctic seas. [ABSTRACT FROM AUTHOR]

This research provides an extensive analysis of the biodiversity and distribution patterns of copepod crustaceans associated with octocoral species. A comprehensive dataset comprising 966 records pertaining to 233 copepod species, encompassing 54 genera, 18 families, and 3 orders, was compiled from 92 scientific papers published between 1858 and 2023, and updated as open data to GBIF. These copepods were found to be closely associated with 183 octocoral species, representing 72 genera and 28 families. The analysis revealed a total of 393 distinct interspecific associations between copepods, classified under the orders Cyclopoida, Harpacticoida, and Siphonostomatoida, and diverse octocorals. Approximately 60% of these associations were reported only once in the literature, which poses challenges to assessing the level of host specificity among the majority of copepod species linked with octocorals. Notably, over 91% of the recorded copepod species were found at depths not exceeding 30 m, with only four copepod species reported at greater depths surpassing 500 m. The presence of these symbiotic copepods was documented across 215 sampling sites situated within 8 of the 12 defined marine ecoregions, with particular attention to the Western Indo-Pacific, Central Indo-Pacific, and Temperate Northern regions. Despite the comprehensive examination of available data, this study highlights substantial gaps in our comprehension of copepod crustacean diversity and distribution in association with octocorals. Moreover, crucial information concerning symbiotic copepods is conspicuously absent for approximately 94% of potential octocoral host species. These disparities emphasize the imperative need for further scientific inquiry to unveil the intricacies of symbiotic relationships and to contribute to a more holistic understanding of copepod–octocoral associations. [ABSTRACT FROM AUTHOR]

The Living Docks restoration program was implemented in the Indian River Lagoon (IRL), Florida, with the goal of affixing oyster restoration mats to dock pilings to promote the growth of filter feeding benthic organisms which can help improve local water quality. However, the relationship between IRL water quality parameters and the presence of filter feeders on the mats is not entirely clear. This study investigates the presence of benthic organisms on eight Living Docks which were deployed throughout the central part of the IRL. Environmental factors (e.g., water salinity, turbidity, pH, and temperature) were collected from the closest available water station to each dock. The main goal was to identify the presence and overall change in percent cover of specific benthic organism(s), those which are known filter feeders, in relationship to environmental parameters. Among functional groups which were identified, barnacles, biofilms, encrusting bryozoans (EBs), oysters, and sponges demonstrated significantly higher cover than the others. Barnacles were higher in abundance at specific dock locations and an increased water pH (up to 8.1), turbidity, and temperature. EB presence was positively impacted by salinity but did not respond to changes in turbidity or temperature within the measured ranges. Oysters were not observed to be impacted by any of the factors within measured ranges. Sponges had sustained abundance in half of the docks in this study. However, they did not respond to any of the environmental factors within measured ranges in different seasons. Results from this study can help target future Living Dock locations which will provide the best environment for the recruitment of filter feeding organisms. [ABSTRACT FROM AUTHOR]

Copyright of Acta Biológica Colombiana is the property of Universidad Nacional de Colombia, Facultad de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Trace elements in aquatic ecosystems are considered as major pollutants due to their environmental persistence, toxicity and ability to be incorporated into food webs. Contaminated sediments represent a threat to benthic macroinvertebrates which in turn expose high trophic organisms to hazardous trace elements, therefore metals accumulated in benthic organisms can also be bio concentrated in food webs. Direct toxic effects of metals include changes in diversity and abundance of benthic invertebrates while, indirect effects include modifications of species interactions and reductions in food quality. In this work, we study the potentially toxic metal concentrations in both sediments and benthic macroinvertebrates in the Maipo River basin (central Chile) evaluating the risk assessment of sediment, toxicity to the biota and bioaccumulation in the organisms. Sediments and benthic organisms were sampled in spring (October-December) 2016 from four sites of the Maipo River basin. Twelve trace elements (As, Al, Cd, Cu, Cr, Hg, Fe, Mn, Mo, Ni, Pb and Zn) were determined by AAE. The Geo accumulation index showed that Zn was moderate to strong pollute in all sites and the enrichment factor showed that there were no important anthropic impacts in the river. High level of contamination was found for Cu in PEL and the pollution index showed that PEL was extremely polluted. Three (Cu, Mn and Zn) out of the five metals analyzed were the elements which presented the largest toxicity to organisms in these aquatic systems based on the Threshold Effect Concentration (TEC) and Probable Effect Concentration (PEC) analysis. Most of the metals analyzed did not show bioaccumulation; however, Ni and Pb were the metals with the highest bioaccumulation factor in all the studied sites. [ABSTRACT FROM AUTHOR]

Differences and similarities between spiny lobster' sexes diet could result from multifactorial environmental influence. We evaluated the trophic spectrum for Panulirus argus, estimated lobster's selectivity, and corroborated the hypothesis that lobster' sexes diet is similar between subzones with different benthic community in two fishing subzones of the gulf of Batabano, Cuba. Stomach contents of 52 lobsters from Diego Pérez (DP), and 68 from Aguardiente (AA), were analyzed. Frequency of occurrence (FO), gravimetric (G), and relative importance (IIR) indices were calculated for each food category. Ellenberg Similarity (ISe), Morisita, and Ivlev Selectivity (E) indices were also applied. Different diet descriptors were also related to benthic community attributes also used to compare between subzones and sexes. Trophic spectrum for P. argus consisted of gastropods, bivalves, polyplacophores, sea urchins, stomatopods, brachyurans, anomurans, polychaetes, ophiuroids, sponges, foraminifera, hydrozoans, fish, and plant matter. The E index showed a P. argus positive selectivity for gastropods Costoanachis sp., Diodora sp., Lucapina sp., Rissoina sp., Fasciolaria tulipa, and Gibberula fluctuata, the bivalves Arcopsis sp., Barbatia domingensis, Antillipecten antillarum, and Codakia orbicularis, and crustaceans of the Order Stomatopoda. Selectivity was highest but negative for Pinctada imbricata, Tucetona pectinata, Chione sp., and anomurans. Diet between sexes was similar in DP (ISe = 47.1%) and the same in AA (ISe = 97.6%), both with high trophic level overlap. Lobster's diet descriptors and the diet for each sex were similar (medium level) between subzones, while the attributes of the benthic community were different. Similarities between diets for each sex were kept despite differences in benthic community-specific composition. [ABSTRACT FROM AUTHOR]

Featured Application: A simple model was developed to select indicator species based on individual species' contributions to biodiversity. Targeting biodiversity can be used for environmental monitoring and to inform restoration designs. In both ecological research and engineering, the selection of indicator species is crucial. Biodiversity has always been an important policy objective for ecologists and environmental managers. Based on this target requirement, we developed a method that reveals the individual contributions of species to biodiversity to quantitatively identify indicator species for selection during environmental monitoring. The Siangshan Wetland in Hsinchu, Taiwan, was selected as an application case. The spread of mangroves not only changed the original habitat composition and function of benthic organisms in wetlands, but also led to problems such as estuary filling, flooding, and black mosquito breeding. Therefore, a large-scale mangrove removal project was undertaken by the Hsinchu City Government from October 2015 to March 2016. In this study, the biological effects of mangrove removal on benthic organisms and adjacent habitats were investigated from October 2015 to September 2016. According to biodiversity contribution algorithms, we identified five indicator species, namely, Mictyris brevidactylus, Macrophthalmus banzai, Uca arcuata, U. lacteal, and U. borealis. These indicator species had the most prominent biodiversity contribution, and they provided direct evidence of the beneficial effect of mangrove removal for wetland restoration. After mangrove deforestation, tidal flat species returned to their original habitats, and their related densities increased significantly in mangrove removal areas. Improving our understanding of the relationships between biodiversity and indicator species is crucial for the development of coastal management processes. Mangrove removal can be confirmed as an appropriate habitat rehabilitation strategy for benthic organisms. Consequently, these indicator species and the results obtained can provide valuable ecological information for those involved in coastal management or other officials seeking to control the spread of mangroves. [ABSTRACT FROM AUTHOR]

Simple Summary: The sediments on the seafloor are inhabited by multiple macroscopic organisms such as shells and worms, which, among other things, influence the biogeochemical cycling by flushing the near-bottom water through their gangways. This is called bioirrigation, one of key processes in the functioning of marine sediments. The density of animals, in addition to the features (or traits) of each species, define their specific contributions to this process. Measuring the intensity of this rather dynamic process in nature is difficult and costly; therefore, the available direct observations are too scarce for large-scale assessments. However, such assessments are essential for broadening our understanding of ecosystem functioning, and of the role that biodiversity plays in it. To address this shortage of observational data, a traits-based index "BIPc" that expresses the bioirrigation potential, based on available data on sediment-dwelling animals, comes into play. In this paper, we focus on the performance of the BIPc index in the south-western Baltic Sea, and on how it changes in space and time. The results support the usefulness of this index, but also highlight its existing limitations. Modelled distribution map layers of the bioirrigation potential and scores for 120 key species required for index calculation are made available for reuse. Benthic community bioirrigation potential (BIPc), an index developed to quantify the anticipated capacity of macrofauna to influence the solute exchange at the sediment–water interface, was calculated for the south-western Baltic Sea. This index can be regarded as an effect trait that is useful for predicting ecosystem processes impacted by animal burrow ventilation. The special feature, and presumably an advantage, of BIPc, compared to alternative recently developed benthic macrofauna-based bioirrigation indices, lies in its ability to distinguish the taxa-specific score values between diffusion- and advection-dominated sediment systems. The usefulness of the BIPc index was compared against the estimates of the well-established community bioturbation potential index (BPc). The BIPc index displayed a moderately but significantly stronger correlation with estimates of irrigation rates derived from tracer experiments. Using a random forest machine learning approach and a number of available relevant environmental predictor layers, we have modelled and mapped the spatial differences in this ecosystem functioning expression. The key species contributing to bioirrigation potential in the study area were identified. The interannual variation in BIPc was assessed on a small exemplary dataset. The scores required to calculate the index, that were assigned to 120 taxa dominating abundance and biomass in the region, are provided for reuse. The utility, temporal variability and uncertainty of the distribution estimate are discussed. [ABSTRACT FROM AUTHOR]

Non‐random community changes are becoming more frequent in many ecosystems. In coral reefs, changes towards communities dominated by other than hard corals are increasing in frequency, with severe impacts on ecosystem functioning and provision of ecosystem services. Although new research suggests that a variety of alternative communities (i.e. not dominated by hard corals) exist, knowledge on the global diversity and functioning of alternative coral reef benthic communities, especially those not dominated by algae, remains scattered. In this systematic review and meta‐analysis of 523 articles, we analyse the different coral reef benthic community changes reported to date and discuss the advantages and limitations of the methods used to study these changes. Furthermore, we used field cover data (1116 reefs from the ReefCheck database) to explore the biogeographic and latitudinal patterns in dominant benthic organisms. We found a mismatch between literature focus on coral‐algal changes (over half of the studies analysed) and observed global natural patterns. We identified strong biogeographic patterns, with the largest and most biodiverse biogeographic regions (Western and Central Indo‐Pacific) presenting previously overlooked soft‐coral‐dominated communities as the most abundant alternative community. Finally, we discuss the potential biases associated with methods that overlook ecologically important cryptobenthic communities and the potential of new technological advances in improving monitoring efforts. As coral reef communities inevitably and swiftly change under changing ocean conditions, there is an urgent need to better understand the distribution, dynamics as well as the ecological and societal impacts of these new communities. [ABSTRACT FROM AUTHOR]

The use of living organisms to provide information on the quality of aquatic environments is now a widely accepted methodology for assessing contaminant bioavailability. Molluscs have developed tolerance mechanisms towards environmental stressors and can accumulate a large range of contaminants. The assessment of marine environment quality was based on heavy metals (HM), persistent organic pollutants (organochlorine pesticides - OCPs and polychlorinated biphenyls - PCBs) and polynuclear aromatic hydrocarbons (PAHs) analysis in Mytilus galloprovincialis, Rapana venosa, Anadara kagoshimensis species sampled during 2016 - 2020 along Romanian Black Sea coast. Toxic metals (cadmium, lead) had bioaccumulation levels below threshold values in most molluscs samples investigated. Cadmium registered few values (15%) surpassing maximum admissible levels, in all three species. Data evaluation demonstrated the maintenance of a high level of concentrations of persistent organic pollutants in the mollusc tissue, but also of the exceedances of the values that characterize the good ecological status of these compounds. Polynuclear aromatic hydrocarbons showed a declining trend and no exceeding of the maximum allowed limit for benzo[a]pyrene was recorded in the last years. In consequence, the overview assessment based on "OneOutAllOut" (OOAO) approach, considering all groups of substances, indicates a bad chemical status for this period. [ABSTRACT FROM AUTHOR]

It is imperative to understand the carbon (C) and nitrogen (N) pools in tropical mangrove systems considering the diminished C storage potential and increasing nutrient loading in a global context due to rising anthropogenic disturbances. Here, we report that the Mangalavanam Coastal Wetland (MCW), a tropical mangrove stand, is a C‐rich environment, with high sediment total organic carbon (70.35 ± 23.84 mg/g) and the δ13C (−26.56 ± 0.65‰) signatures indicate that the major source of carbon in the study area is from mangrove litter. The total nitrogen concentration in the sediment (3.78 ± 0.18 mg/g) was high despite the low N environment of mangrove ecosystems where the mangrove leaf litter was a major contributor to C. The sediment δ15 N (7.70 ± 0.23‰) signatures indicated that the influence of anthropogenic N discharges and the contribution of marine algae were the primary cause of N enrichment. The mean δ13C and δ15N signatures of the mature mangrove leaves of the MCW were −28.66 ± 1.04‰ and 5.93 ± 0.65‰, respectively. The mangrove dweller crab Parasesarma plicatum was observed to have enriched δ13C (−23.78 ± 0.33‰) and δ15N (6.54 ± 0.35‰) signatures, indicative of a mixed dietary source. This study provides the impetus for ongoing conservation efforts to limit the loss of carbon storage and protect against the impact of anthropogenic nitrogen loadings on lowering the carbon and nitrogen emission potential for this system, which can have implications for other tropical mangrove systems as well. [ABSTRACT FROM AUTHOR]

As part of efforts to restore fishery resources and recover damaged coastal ecosystems, artificial reefs are often anchored on the seafloor in coastal zones, to provide new habitats for marine organisms. The aim of the study was to describe the structure of a community of benthic invertebrates colonising a niche-type artificial reef (AATN in Spanish). Nine structures were anchored at depths of 16 ± 1.5 m for 99 weeks (22 months) in the Area of Benthic Resource Management and Exploitation (AMERB) in coastal waters of the Region of Bio Bio, Chile. The results showed that, at 3 months from submersion of the NTAR, much of the artificial substrate remained bare and there were only low levels of specimens of Balanus sp. barnacles, showing mean coverage of 11.26%, and even lower proportions of Rhodophyta, with mean coverage of 0.34%. At 6 months, the presence of hydrozoans was seen, decreasing the coverage of the barnacles, which was aided further at 8 months with the arrival of barnacle predatory invertebrates. At 8 months, new benthic invertebrates appeared and competed for the substrate. These included sponges and algae. At 99 weeks, the hydrozoans dominated the substrate, followed by barnacles and Rhodophyta, the first colonising organisms, leading to colonisation by motile macro-invertebrates, mainly consisting of crustaceans, echinoderms and molluscs. The AATN artificial system provides an ideal substrate for the development of early ecological succession and the use of this technology should be feasible in the recovery process of habitat damaged by anthropogenic actions and climate change. [ABSTRACT FROM AUTHOR]

A comparative analysis of the current content of petroleum hydrocarbons in various components of the ecosystem was performed to assess the ecological state of the southeastern part of the Onega Bay (White Sea) that suffered from a spill of fuel oil in 2003. The analysis showed relatively low levels of petroleum hydrocarbon concentrations: from 0.34 to 4.55 mg/kg, with a median of 1.41 mg/kg in bottom sediments; from 9.41 to 14.25 mg/kg, with a median of 12.30 mg/kg in tissues of benthic organisms; and below 1 MPCfishery (the maximum permissible concentration) in water. The records of low concentrations of bacteria that use petroleum hydrocarbons (fuel oil) allow us to conclude that the state of the examined ecosystem is close to the natural condition. [ABSTRACT FROM AUTHOR]

We use a linear stability approach to develop a process-based morphodynamic model including a two-way coupling between tidal sand wave dynamics and benthic organisms. With this model we are able to study both the effect of benthic organisms on the hydro- and sediment dynamics, and the effect of spatial and temporal environmental variations on the distribution of these organisms. Specifically, we include two coupling processes: the effect of the biomass of the organisms on the bottom slip parameter, and the effect of shear stress variations on the biological carrying capacity. We discuss the differences and similarities between the methodology used in this work and that from 'traditional' (morphodynamics only) stability modelling studies. Here, we end up with a 2 × 2 linear eigenvalue problem, which leads to two distinct eigenmodes for each topographic wave number. These eigenmodes control the growth and migration properties of both sand waves and benthic organisms (biomass). Apart from hydrodynamic forcing, the biomass also grows autonomously, which results in a changing fastest growing mode (FGM, i.e. the preferred wavelength) over time. As a result, in contrast to 'traditional' stability modelling studies, the FGM for a certain model outcome does not necessarily have to be dominant in the field. Therefore, we also analysed the temporal evolution of an initial bed hump (without perturbing biomass) and of an initial biomass hump (without perturbing topography). It turns out that these local disturbances may trigger the combined growth of sand waves and spatially varying biomass patterns. Moreover, the results reveal that the autonomous benthic growth significantly influences the growth rate of sand waves. Finally, we show that biomass maxima tend to concentrate in the region around the trough and lee side slope of sand waves, which corresponds to observations in the field. [ABSTRACT FROM AUTHOR]

Copyright of Research of Environmental Sciences is the property of Research of Environmental Sciences Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

While the study of dispersal and connectivity in the ocean typically centres on pelagic species and planktonic larval stages of benthic species, the present work explores an overlooked locomotor means in post‐settlement benthic stages that redefines their dispersal potential.Members of the echinoderm class Holothuroidea colonize a diversity of marine environments world‐wide, where they play key ecological and economical roles, making their conservation a priority. Holothuroids are commonly called sea cucumbers or sea slugs to reflect their slow movements and are assumed to disperse chiefly through pelagic larvae.The present study documents and explores their unexpected ability to actively modify their buoyancy, leading them to tumble or float at speeds orders of magnitudes faster than through benthic crawling. Two focal species representing different taxonomic orders, geographic distributions and reproductive strategies were studied over several years.Active buoyancy adjustment (ABA) was achieved through a rapid increase in water‐to‐flesh ratio by up to 740%, leading to bloating, and simultaneously detachment from the substrate. It occurred as early as 6 months post settlement in juveniles and was recorded in wild adult populations. In experimental trials, ABA was triggered by high conspecific density, decreasing salinity and increasing water turbidity. Based on field video footage, ABA‐assisted movements generated speeds of up to 90 km/day.These findings imply that displacement during planktonic larval stages may not supersede the locomotor capacity of benthic stages, challenging the notion of sedentarity. Combining the present results and anecdotal reports, ABA emerges as a generalized means of dispersal among benthic animals, with critical implications for world‐wide management and conservation of commercially and ecologically significant species. [ABSTRACT FROM AUTHOR]

The present study assessed biochemical responses as sublethal endpoints in the polychaete Armandia agilis exposed to contaminated sediments to in order to assess its potential use as a test organism. Sediment samples from several locations at a dredging site were obtained and used in whole-sediment exposures. Samples were tested with A. agilis to determine the 10-day toxicity of the 100% sample and the enzymatic activity of catalase (CAT), glutathione-S-transferase (GST) and acetylcholinesterase (AChE) biochemical measurements made in whole-body homogenates of a subset of the surviving organisms. Biochemical responses reported in A. agilis were not statistically different from the reference site sediment, however, the integrated analysis demonstrated that contaminants bound to sediment samples influenced the sublethal effects. [ABSTRACT FROM AUTHOR]

The presence of potentially toxic elements (PTE) was determined in different tissues of five selected marine organisms. The As, Cd, Cu, Mn, Mo, Ni, Pb and Zn concentrations were measured in the seagrass Cymodocea nodosa , the green alga Cladophora echinus , the red alga Gelidiella lubrica , the marine topshell Phorcus turbinatus and the littoral crab Carcinus aestuarii , as well as in seawater from Makirina Bay. The levels of As, Cd, Cu, Mn and Zn in the biota were found to exceed those in previously analysed sediments, indicating the bioaccumulation of these PTE. The biota-sediment accumulation factor (BSAF) and concentration factor (CF) varied among different organisms. As regards the five selected species, C. nodosa , C. echinus and G. lubrica proved to be the strongest accumulators of Mn, while P. turbinatus and C. aestuarii showed a high capacity to accumulate As, Cd, Cu and Zn. These species can be considered as good ecological indicators in the assessment of PTE pollution in marine littoral environments. [ABSTRACT FROM AUTHOR]

The paper presents data on a comparative study of the bioaccumulation of trace elements in benthic organisms at the shelf in the Yenisei estuary in the Kara Sea and an area of methane seeps in the Deryugin Basin in the Sea of Okhotsk. The data pertain to both essential elements (Fe, Mn, Ni, Co, Cr, and Cu), which are necessary, in certain concentrations, for the metabolism of organisms, and nonessential heavy metals (Cd, Pb, and Hg), as well as As, a toxic metalloid, whose concentrations are subject to standards issued by the World Health Organization for various environments and seafoods. Our data showed that dominated representatives of the bottom-living fauna from the estuary of the Yenisei River (isopoda Saduria spp. and bivalve Portlandia spp.) and from the Deryugin Basin (actinia Actiniaria and clam Vesicomyidae family) were characterized by high bioaccumulation coefficients of most of the elements (≥n × 103), regardless of their biochemical properties. The use of the coefficient K, which characterizes the accumulation of trace elements in the soft tissues of bivalves relative to their shells, allowed us to detect differences in the character of bioaccumulation. In the mussels (both filter-feeding and suspension-feeders) from the Yenisei estuary, K < 1 for most of the elements (Mn, Fe, Cr, Co, Ni, and As), and this suggests that these elements were preferably accumulated in the carbonate shells. Conversely, symbiotrophic Vesicomyidae clams from the Deryugin Basin were characterized by the preferable accumulation of all of the trace elements in gills and soft tissues (the coefficient K ≫ 1). The likely reasons for this are thought to be different effect of abiotic (biological availability of elements and water turbidity) and biotic (throphic strategies) factors of the habitats. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Biologia Marina y Oceanografía (RBMO) is the property of Universidad de Valparaiso, Facultad de Ciencias del Mar and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study was carried out on Shushica River, a branch of Vjosa River, located in the Vlora district south west Albania, during 2017. This river flows from the Kuçi area parallel with the main road in all her longitude. The recent process of rehabilitation of this road and the process of human population growth in this region is expected to have a severe impact in watershed and water quality of this area through reduction of microhabitat diversity and its associated biodiversity. During this study three stations were chosen randomly on the stream and samples were taken seasonally (Spring and Summer 2017). Here we are presenting the preliminary data based on the identification of a total number of 841 organisms. The collected samples include organisms from class: Annelid (Oligochaeta) and Insecta. Insects are dominating throughout all the sampling period. Between organisms of class Insecta dominant are the families Chironomidae and Simulidae (Diptera), Elmidae (Coleoptera), Hydropsychidae (Trichoptera), and Heptagenidae (Ephemeroptera). Based on the collected data the EPT index (abundances in the sample of the organisms belonging to the orders Ephemeroptera, Plecoptera and Trichoptera in comparison to the total number of organisms in the sample) was calculated. Based on the published data of different recent studies the water quality of the river is related directly with the higher relative abundance of those taxa. [ABSTRACT FROM AUTHOR]

The Western Antarctic Peninsula (WAP) has undergone significant changes in air and seawater temperatures during the last 50 years. Although highly stenotherm Antarctic organisms are expected to be severely affected by the increase of seawater temperature, high-resolution datasets of seawater temperature within coastal areas of the WAP (where diverse marine communities have been reported) are not commonly available. Here we report on within-year (2016-2017) variation in seawater temperature at three sites on Doumer Island, Palmer Archipelago, WAP. Within a year, Antarctic organisms in South Bay were exposed to water temperatures in excess of 2 °C for more than 25 days and 2.5 °C for more than 10 days. We recorded a temperature range between1.7° to 3.0 °C. Warming of seawater temperature was 3.75 times faster after October 2016 than it was before October. Results from this study indicate that organisms at South Bay are already exposed to temperatures that are being used in experimental studies to evaluate physiological responses to thermal stress in WAP organisms. Continuous measurements of short to long-term variability in seawater temperature provides important information for parametrizing meaningful experimental treatments that aim to assess the local effects of environmental variation on Antarctic organisms under future climate scenarios. [ABSTRACT FROM AUTHOR]

Taihu Lake area is one of the densest metropolitan areas in the world including diverse industrial activity. In the present study, the snail ( Bellamya aeruginosa) and sediment were collected from the Taihu Lake area to investigate the contamination status, congener pattern, spatial distribution, and bioaccumulation effect of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). The samples underwent liquid extraction, lipid removal by sulfuric acid, and acidic silica gel column, and subsequently analyzed by gas chromatography-electron capture detector (GC-ECD) and gas chromatography-mass spectrometry (GC-MS). Concentration of ∑PCBs ranged between 90 and 680 ng g lipid weight in the snails and between 0.018 and 0.82 ng g dry weight in the sediments. Concentration of ∑PBDEs varied from 25 to 200 ng g lipid weight in the snails and from 0.62 to 67 ng g dry weight in the sediments. The levels of PCBs and PBDEs observed were in the medium to low range compared with other studies in the world. CB-153 was the predominant PCB congener in both snails and sediments whereas BDE-209 showed a low bioavailability in the snails, even if it contributed up to 70% of ∑PBDEs in the sediments. The spatial distribution showed that the highest concentration of PCBs and PBDEs were detected in samples from Zhushan Lake. East Taihu Lake and Dianshan Lake showed lower concentration of PCBs and PBDEs than the other sampling sites. Biota-sediment accumulation was found between snails and sediments of most of PCB and PBDE congeners except for the highly brominated BDEs (i.e., BDE-209). Therefore, sediment is suggested to be an appropriate matrix to monitor BDE-209 while aquatic species such as the snail could be good for monitoring of PCBs and lower brominated BDE congeners. No significant correlation (Spearman correlation test, two-tailed) of CB-153 ( r = 0.54, p = 0.27) or BDE-47 ( r = 0.60, p = 0.21) was found between snails and sediments. [ABSTRACT FROM AUTHOR]

A broadly accepted framework for prospective environmental risk assessment (ERA) of sediment-bound organic chemicals is currently lacking. Such a framework requires clear protection goals, evidence-based concepts that link exposure to effects and a transparent tiered-effect assessment. In this paper, we provide a tiered prospective sediment ERA procedure for organic chemicals in sediment, with a focus on the applicable European regulations and the underlying data requirements. Using the ecosystem services concept, we derived specific protection goals for ecosystem service providing units: microorganisms, benthic algae, sediment-rooted macrophytes, benthic invertebrates and benthic vertebrates. Triggers for sediment toxicity testing are discussed. We recommend a tiered approach (Tier 0 through Tier 3). Tier-0 is a cost-effective screening based on chronic water-exposure toxicity data for pelagic species and equilibrium partitioning. Tier-1 is based on spiked sediment laboratory toxicity tests with standard benthic test species and standardised test methods. If comparable chronic toxicity data for both standard and additional benthic test species are available, the Species Sensitivity Distribution (SSD) approach is a more viable Tier-2 option than the geometric mean approach. This paper includes criteria for accepting results of sediment-spiked single species toxicity tests in prospective ERA, and for the application of the SSD approach. We propose micro/mesocosm experiments with spiked sediment, to study colonisation success by benthic organisms, as a Tier-3 option. Ecological effect models can be used to supplement the experimental tiers. A strategy for unifying information from various tiers by experimental work and exposure–and effect modelling is provided. [ABSTRACT FROM AUTHOR]

The chronic exposure of benthic organisms to metals in sediments can lead to the development of tolerance mechanisms, thus diminishing their responsiveness. This study aims to evaluate the accumulation profiles of V, Cr, Co, Ni, As, Cd, Pb and Hg and antioxidant system responses of two benthic organisms ( Cerastoderma edule, Bivalvia; Nephtys hombergii, Polychaeta). This approach will provide clarifications about the ability of each species to signalise metal contamination. Organisms of both species were collected at the Tagus estuary, in two sites with distinct contamination degrees (ALC, slightly contaminated; BAR, highly contaminated). Accordingly, C. edule accumulated higher concentrations of As, Pb and Hg at BAR compared to ALC. However, antioxidant responses of C. edule were almost unaltered at BAR and no peroxidative damage occurred, suggesting adjustment mechanisms to the presence of metals. In contrast, N. hombergii showed a minor propensity to metal accumulation, only signalising spatial differences for As and Pb and accumulating lower concentrations of metals than C. edule. The differences in metal accumulation observed between species might be due to their distinctive foraging behaviour and/or the ability of N. hombergii to minimise the metal uptake. Despite that, the accumulation of As and Pb was on the basis of the polychaete antioxidant defences inhibition at BAR, including CAT, SOD, GR and GPx. The integrated biomarker response index (IBRv2) confirmed that N. hombergii was more affected by metal exposure than C. edule. In the light of current findings, in field-based studies, the information of C. edule as a bioindicator should be complemented by that provided by another benthic species, since tolerance mechanisms to metals can hinder a correct diagnosis of sediment contamination and of the system's health. Overall, the present study contributed to improve the lack of fundamental knowledge of two widespread and common estuarine species, providing insights of the metal accumulation profiles under a scenario of chronic contamination. Finally, this work provided useful information that can be applied in the interpretation of future environmental monitoring studies. [ABSTRACT FROM AUTHOR]

Background: Recent studies have reported that soft tunic syndrome (STS) in the edible ascidian Halocynthia roretzi is caused by the kinetoplastid parasite Azumiobodo hoyamushi. In this study, we attempted to detect and quantify the pathogen in benthic animals. Methods: Four species of ascidians, three species of echinoderms, two species of bivalves, one species each of sponge and algae, as well as seawater, were collected in 2014 and 2015 from an ascidian farm on the southern coast of Korea by SCUBA diving. Samples were collected from ascidian hanging culture ropes or the sea bottom. Inhalent siphons were excised for the analysis of ascidians, and soft body tissues were excised from the other species. Membrane filters were used to filter collected seawater. Tissues and membrane filters were analysed using culture testing, PCR testing, and qPCR diagnoses. Results: Only organisms belonging to Ascidiacea are susceptible to A. hoyamushi infection. The infection rate (% infected of the total number collected) and infection intensity (number of cells infected/g tissue wet weight) varied depending on the seasonal variation in seawater temperatures. Most ascidians examined were infected with A. hoyamushi and showed higher infection intensity in cold water seasons (April 2014 and February 2015), followed by a dramatic drop during warm water seasons (August and November, 2014). In addition, infection intensity of A. hoyamushi during the warm water period was higher in ascidians from the sea bottom than those from the hanging culture rope. Conclusions: Among benthic organisms that inhabit the southern coast of Korea, most ascidians are susceptible to A. hoyamushi infection. Seasonal cycle of infection rates and intensities of the pathogen correspond well with the STS disappearance and onset cycle observed in ascidian farms. The high intensity of A. hoyamushi infection in the ascidians on the sea bottom of ascidian farms during summer suggest further studies on the role of the pathogen in resumption of STS occurrence in late fall or early winter in the southern coast of Korea. [ABSTRACT FROM AUTHOR]

Sewage treatment plants in Ilha Solteira City, which consist of stabilization ponds, have been modifying water and sediment characteristics around sewage outfall area. Water quality parameters such as dissolved oxygen (OD) and conductivity were directly influenced by the sewage outfall. OD values were reported before (6.36 mg L-1) and after (2.94 mg L-1) the sewage outfall. Measurement of organic matter content in the sediment showed the same pattern, with values of 1.34% and 4.80% for the SP1 and SP3 samples, respectively. A copper and zinc analysis indicated that metals are being transported through the water column, and SP3 is an important sedimentation zone. The total concentrations reported for copper are 6.48, 26.97, 37.54, 27.12 and 18.55 mg kg-1 for SP1, SP2, SP3, SP4 and SP5, respectively, and the total concentrations for zinc are 11.21, 48.53, 67.41, 58.62 and 24.76 mg kg-1 . Bureau Community of Reference (BCR) sequential extraction indicated the following bioavailability order of copper and zinc: SP1 < SP5 < SP4 < SP3 < SP2. At SP2, more than 70% of the copper and zinc is found in bioavailable fractions. Benthic organism's analysis indicates that the Oligochaetes correlation with organic matter content is related to the decrease in water quality. [ABSTRACT FROM AUTHOR]

We compared the environmental and biotic characteristics of farm ponds with and without the invasive fish, largemouth bass ( Micropterus salmoides), and bluegill ( Lepomis macrochirus), with varying degrees of aquatic vegetation cover in western Japan. Redundancy analysis (RDA) revealed that aquatic vegetation cover and pond area were significant environmental variables in explaining the variance in aquatic organisms. Aquatic vegetation cover predominantly affected Odonata and Hemiptera larvae, and the native cyprinid, Hemigrammocypris rasborella, while the pond area mainly affected the two exotic fishes (largemouth bass and bluegill), Viviparidae, Oligocheata, Ephemeroptera, and chironomid larvae. In the RDA biplot for aquatic organisms, the RDA1 axis appeared to separate the exotic fish group (bluegill, largemouth bass, Gammaridae, Oligochaeta, Viviparidae, Ephemeroptera, Trichoptera, and chironomid larvae) from the native fish group ( H. rasborella, Oryzias latipes, Rhinogobius sp., Odonata, shrimps, and Hemiptera larvae). The best path model results indicated that the presence of piscivorous largemouth bass had a significantly negative effect on native fish numbers; largemouth bass also had a positive indirect effect on benthic organism numbers. Our data suggest that the depletion of native fishes via top-down effects by exotic largemouth bass may indirectly increase the number of benthic organisms as a result of trophic-cascading effects. [ABSTRACT FROM AUTHOR]

The EFSA Panel on Plant Protection Products and their Residues (PPR Panel) was tasked to revise the Guidance Document (GD) on Aquatic Ecotoxicology under Council Directive 91/414/EEC (SANCO/3268/2001 rev. 4 (final), 17 October 2002). This scientific opinion of the PPR Panel is the second of three requested deliverables within this mandate. The scientific background for the risk assessment on sediment organisms in edge-of-field surface waters is provided, with reference to benthic ecology and ecotoxicology, available test protocols and current knowledge on exposure and effects of sediment-bound plant protection products (PPPs). The scientific opinion provides approaches on how to derive regulatory acceptable concentrations (RACs) for sediment organisms and exposure to active substances of PPPs and transformation products of these substances, and how to link them in a tiered approach to predicted environmental concentrations (PECs) for the sediment compartment. A list of uncertainties in relation to such approaches is given. [ABSTRACT FROM AUTHOR]

In order to understand physiological, ecological and biological processes, it is often crucial to determine an organism's volume and surface area ( SA). Most of the available methods require sacrificing the organism or at least removing it from its natural habitat, in order to measure these parameters. Advances in computer vision algorithms now allow us to determine these parameters using non-destructive, three-dimensional modelling. The addition of cloud computing and the availability of freeware make this tool widely accessible., Photographs of corals and sponges were taken in natura and used to create digital 3D models using the 'structure-from-motion' technique. Modelling was done online using 123 D Catch freeware (Autodesk Inc.). Volume and SA of the corals and sponges were calculated from these 3D models., Comparing in situ 3D modelling to current measuring methods (e.g. water displacement, paraffin dipping) showed that volume calculation by 3D modelling gave fast results accurate to within 8% of estimated true volume. Using cloud computing enabled the creation of a 3D model in <30 min. SA accuracy was found to differ significantly, depending on the shape of the modelled object, with an accuracy ranging widely from 2% to 18%., We found that in situ volume and SA measurements created by 3D modelling enable easy, fast and non-intrusive studies of benthic aquatic organisms, without removing the subject organisms from their habitat, thus enabling continuous study of natural growth over extended time periods. The freely available freeware, along with ease of use, makes this method accessible to many areas of research. [ABSTRACT FROM AUTHOR]

Pharmaceutical products are found in low concentrations constantly released into the environment, which contribute to their persistence. In this study, a battery of recognized short-term bioassays was applied to evaluate the risk assessment of sediment samples spiked with pharmaceutical products: carbamazepine, ibuprofen, fluoxetine, 17α-ethynylestradiol, propranolol, and caffeine, including the environmental concentrations. Two phases of the sediments (elutriate and whole sediment) were evaluated through the determination of seven endpoints: bioluminescence inhibition of the bacteria Vibrio fischeri, mortality rate of the amphipods Ampelisca brevicornis, spermiotoxicity and embryotoxicity of the sea urchins Paracentrotus lividus, and microalgae growth rate of Isochrysis galbana and Tetraselmis chuii. Lethal and sublethal responses were analysed after short-term exposure. Results refuted the fact that Microtox® procedures (SPT and Basic phase) and microalgae and amphipods bioassays tested in this study for the quality assessment of pharmaceutical-spiked sediments were sufficient for the protection of the aquatic environment. Between the bioassays used in the present study, sea urchin tests were the most sensitive endpoints, which embryotoxicity showed more sensitive to evaluate the contamination by pharmaceutical products than the spermiotoxicity bioassay. Sea urchin bioassays are recommendable for the quality assessment of sediment contaminated by pharmaceutical products. [ABSTRACT FROM AUTHOR]

Toxicity of titanium dioxide nanoparticles (nano-TiO2) to aquatic organisms can be greatly increased after exposure to ultraviolet (UV) radiation. This phenomenon has received some attention for water column species; however, investigations of nano-TiO2 phototoxicity for benthic organisms are still limited. In the present study, bioassays of 3 representative benthic organisms ( Hyalella azteca, Lumbriculus variegatus, and Chironomus dilutus) were conducted to evaluate nano-TiO2 phototoxicity. When exposed to 20 mg/L of nano-TiO2 and various light intensities (0-30 W/m2), H. azteca was the most sensitive, with a median lethal dose of 40.7 (95% confidence interval, 36.3-44.7) Wh/m2, and hence is a potential model organism in future toxicological guidelines for photoactive nanomaterials to freshwater benthos. Without the presence of nano-TiO2, no mortality was observed in L. variegatus and C. dilutus exposed to UV intensity ranging from 0 W/m2 to 41 W/m2. However, a sharp drop of H. azteca survival was observed when UV intensity was higher than 9.4 W/m2, demonstrating the importance of UV-only effects on the ultimate phototoxicity of nanomaterials. Furthermore, both bioavailability and surface attachment of nano-TiO2 onto organisms were affected by the exposure scenario, supported by the exposure scenario-dependent phototoxicity seen in H. azteca and C. dilutus. Overall, the present study demonstrates the importance of species sensitivity and exposure scenarios in future test guidelines of nano-phototoxicity. Environ Toxicol Chem 2014;33:1563-1569. © 2014 SETAC [ABSTRACT FROM AUTHOR]

The Brazilian reef fauna shows high levels of endemism, with both the continental coast and oceanic islands considered as unique biogeographic provinces divided in tropical coral reefs (northern and northeast) and subtropical rocky reefs (southern). While assessments and descriptions for the tropical reefs have reported different levels of impact in different regions, the southern ones have not yet been considered. In addition to a baseline assessment of benthic cnidarian cover, we evaluated the condition of the massive coral colonies of Arraial do Cabo, southeastern Brazil. Results indicatedPalythoa caribaeorumas the most abundant cnidarian in all sites followed byMillepora alcicornis, octocorals and scleractinian corals. MostSiderastrea stellatacolonies assessed had filamentous algae covering a major area of their tissues and roughly one-third ofMussismilia hispidacolonies were also covered by algae. Bleaching was detected in less than 5% of colonies of these species. Coral deterioration in the region is historical and includes unreported diseases and bleaching with subsequent algal settlement and succession over colonies. The lack of previous monitoring programmes on benthic organisms makes the discernment of natural and anthropogenic impacts a difficult task. The scenario described here for native corals in Arraial do Cabo requires urgent action with further experimental work on factors that contribute to the demise of the corals. [ABSTRACT FROM PUBLISHER]

Measures of alpha diversity are more frequently used to detect environmental changes and subsequent impacts on biodiversity, while measures based on variability (beta diversity) are said to be more appropriate for detecting those impacts. Theory predicts that beta diversity should increase with disturbance frequency in patchy communities. Our objective in this study was to experimentally determine the effect of high and low disturbance regimes, frequency and intensity combined, on marine benthic alpha and beta diversity. The experiment was conducted in a rock pool system of the St. Lawrence estuary, Canada. Rock pools were disturbed by (1) nutrient enrichment and (2) draining according to three disturbance regimes (none, low, high). Disturbance regimes had little or no effect on alpha diversity of benthic algae and sessile animals. However, the low regime of nutrient enrichment induced greater within-group beta diversity than the reference rock pools, while the high disturbance regime induced equal or even smaller within-group beta diversity compared to the reference. Draining had an opposite effect on benthic beta diversity, with a greater variability of the community structure under the high regime of disturbance. Taking into account the effect of disturbance regimes on beta diversity could provide a useful diagnostic for disturbed benthic communities. [ABSTRACT FROM AUTHOR]

Sediments from Polish coastal environments were classified by a quality assessment approach that took into account trace metal and organic micropollutant concentrations, grain-size distribution, and organic carbon content. Generally, no benthic organisms were found at sites where sediments were classified as heavily polluted. However, areas characterized by a moderate contamination showed a variable composition of the benthic community and changing bioaccumulation patterns; therefore, no single species found in the Gulf of Gdańsk could be considered representative of the whole benthic environment. Although sediment monitoring must be considered a suitable tool to detect hot-spot pollution areas in coastal and inland waters, it should be complemented by bioaccumulation measurements to evaluate the actual risk posed by contaminants to benthic organisms. This “biological information” allows a better appreciation of the real benthic infaunal community exposure to chemicals and can usefully complement the existing sediment quality guidelines. [ABSTRACT FROM AUTHOR]

The environmetric data analysis of analytical datasets from sediment and benthic organisms samples collected from different sampling sites along the coast of Black Sea near to City of Varna, Bulgaria has given some important indications about the bioindication properties of both type of samples. Various multivariate statistical methods like cluster analysis, principal components analysis, source apportioning modeling and partial least square (PLS) modeling were used in order to classify and interpret the parameters describing the chemical content of the coastal sediments (major components, heavy metals and total organic carbon) and benthic organisms (heavy metals). It has been shown that seriously polluted coastal zones are indicated in the same way by all benthic species, although some specificity could be detected for moderate polluted regions’ e.g. polychaeta accumulated preferably Co, Cr, Cu, and Pb; crustacea – As, Cd, and Ni; mollusca – Zn. The identified latent factors responsible for the dataset structure are clearly indicated and apportioned with respect to their contribution to the total mass or total concentration of the species in the samples. The linear regression and PLS models indicated that a reliable forecast about the relation between naturally occurring chemical components and polluting species accumulated in the benthic organisms is possible. [ABSTRACT FROM AUTHOR]

Lake St. Lucia, South Africa's largest estuarine system, was isolated from the sea by a beach berm throughout a severe drought from 2002 to 2007, with the lake water level being extremely low over much of its total area. A reverse salinity gradient resulted, with the lowest salinity in the south near the sea and the highest in the northern lakes. Cholnoky (1968), the first to examine the diatoms of St Lucia and the streams flowing into it, identified 159 diatoms, of which 79 taxa were from the freshwater streams and 80 from the saline lakes. A further study between 1973 and 1975 by Johnson (1976) showed the presence of neritic diatoms as the dominant group in the phytoplankton. During the present survey carried out during 2004 and 2006 only a few taxa from the 1965 survey, and no taxa from the 1976 survey, were recorded. Raphid diatoms were found to survive for months in dry lake bed sediments, in salinity up to five times that of seawater. Species richness increased with depth into the dry sediment, leading to the hypothesis that, when the rains return, the diatom flora would regain species richness and diversity within weeks. Species composition was different at the same sites at different times, indicating that water circulation is responsible for distributing species around the lake, especially during shallow-water, hypersaline drought conditions. No centric diatom taxa were found in the water column, suggesting that there was no true phytoplankton community, only resuspended benthic taxa, in St Lucia at the time of the study. [ABSTRACT FROM AUTHOR]

In this study concentrations of heavy metals, such as Cd, Co, Cu, Fe, Mn, Ni, Pb and Zn were determined in water, sediment, muscle, liver and gill of fish ( Silurus triostegus, Mastacembelus simack, Mystus halepensis, Orthrias euphraticus) the muscle and liver of crab ( Potamon fluviatilis), the internal organs of fresh water snail ( Physa acuta), and mussel (Unio elongatulus), and in whole biomass of green algae ( Spirogyra sp.) examples collected seasonally from three selected sites (I, II, and III) of Tigris River and from a reference site on Resan Creek. In general, the average Cd, Cu, Mn, Ni, Zn, and Fe values in Sites I, II, and III were found to be high in spring and summer. The concentrations of heavy metals in the Tigris River are compared with previous studies in the same sites. The results showed that Cu levels have gradually decreased during recent years. In Tigris River, among the living organisms, i.e., those which are living in benthic region and showing biomonitor characteristic, crab, snail, green algae, mussel and fish are seen to be formed in sequence. Cu, Fe, Mn and Zn values obtained from the muscle of fish and from the mass of internal organs of mussel and snail were found to be under the acceptable values suggested. [ABSTRACT FROM AUTHOR]

An in vitro bioaccessibility test was applied for assessing the transfer of polycyclic aromatic hydrocarbons (PAHs) present in road dust, into benthic organisms living in a receiving water body. The road dust is supposed to be urban runoff particles under wet weather conditions. Sodium dodecyl sulfate (SDS) solution was used as a hypothetical gut fluid. Pyrene, ffuoranthene and phenanthrene were the main PAH species in the SDS extractable fraction of road dust, as well as the whole extract. Benzo(ghi)perylene showed relatively low concentrations in the SDS extract in spite of a high concentration in the original dust. The PAH composition in benthic organisms (polychaetes) did not correspond with that of the surrounding sediment and the PAHs detected were also detected in high concentrations in the SDS extract of road dust. When testing the toxicity of the extracted contaminants by a standardised algal toxicity test, SOS extracts of a detention pond sediment showed higher toxicity than the pore water of the corresponding sediment. Sediment suspension showed a comparative toxicity with 0.1% SDS extract. From the results, the in vitro bioaccessibility test seems more suitable to evaluate the exposed contaminants than the traditional organic solvent extraction method and the SOS extracted fraction is applicable to toxicity tests reflecting the digestive process. [ABSTRACT FROM AUTHOR]

In the current study, the bioconcentration behavior and acute toxicity of two polycyclic musks, Tonalide® 7-acetyl- 1,1,3,4,4,6,-hexamethyl-1,2,3,4,-tetrahydronaphthalene (AHTN) and Galaxolide® 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexa-methylcyclopenta[γ]-2-benzopyran (HHCB), were studied in two benthic organisms. Polycyclic musks are frequently used fragrances, and they have been detected in different compartments of the environment. The aim of this study was to fill some empirical data gaps for AHTN and HHCB for benthic organisms. Results show that differences exist between both organisms. Chironomus riparius exhibited bioconcentration factors (BCFs) for AHTN and HHCB substantially lower than predicted for nontransformed organics. The BCFs for both chemicals increased after coexposure of the organism to the cytochrome P450 inhibitor piperonyl butoxide. Thus, the low BCF values were the result of rapid biotransformation of AHTN and HHCB in the midge larvae. Bioconcentration kinetics indicated that both chemicals induced their own cytochrome P450-mediated metabolism. Acute toxicity of AHTN to midge larvae was reduced compared to predicted baseline toxicity and was similar for HHCB. Bioconcentration of AHTN and HHCB in the worm (Lumbriculus variegatus) is in agreement with predictions based on the octanol-water partition coefficients of these chemicals. Acute toxicity was found to be similar to predicted values for baseline toxicity. Summarizing, for AHTN and HHCB, acute toxicity and bioconcentration behavior in L. variegatus was in accordance with predicted data for nontransformed organics. In C. riparius, bioconcentration as well as toxicity were reduced. [ABSTRACT FROM AUTHOR]

The relationship between the variables of reef fish community structure (fish richness, fish diversity and total number of fishes) and those of habitat complexity (total surface area, substratum diversity, topographic complexity, number of holes, percent cover of turf algae, zoanthids, millepores, massive corals, bare rock, encrusting calcareous algae, urchins, other sessile organisms and Sargassum) were examined on three different rocky shores (FA, FB and FT) at Arraial do Cabo, a tropical region located on Brazilian southeastern coast (23° S, 42° W). Fish abundance and vertical distribution were assessed by a visual census technique using strip transects. Percentage cover of benthic organisms and other substratum types were calculated by replicated transects using a chain laid down on the substratum. Topographic complexity was determined by the chain link method and number of holes were estimated by direct counts on replicated transects. More than 91 fishes belonging to 37 families were seen in all study sites during one year of visual census effort. FA and FB sites had similar fish community structure and habitat complexity characteristics, while FT showed different habitat characteristics and higher fish diversity and richness, plus total number of fishes. Vertical distribution of fishes along the rocky shores studied seemed to be predictable and was determined by factors such as feeding habits and behavior, availability of refuges and social interactions. The habitat variables that best explained the higher diversity and number of fishes observed in FT site were total surface area of rocky shores and the abundance of benthic sessile invertebrates; these conditions were typical of rocky shores more exposed to wave surge. [ABSTRACT FROM AUTHOR]

This paper presents an approach for incorporating species-conditional co-occurrence into models used for the selection of marine indicator species. Mangrove invasion within the Siangshan Wetland in Hsinchu, Taiwan, has changed the original structures and functions of habitats for benthic organisms. The Hsinchu City Government ran a large-scale mangrove removal project from October 2015 to March 2016 to restore the wetland. From October 2015 to September 2016, we investigated the biological effects of mangrove removal on benthic crabs and their adjacent habitats. Density, number of species, Shannon–Weaver index (H′) and Palou's evenness index (J′) were calculated and compared between mangrove and non-mangrove regions. The results showed that values for these attributes in the non-mangrove regions were higher than those of the mangrove regions. After mangrove removal, species returned to their original habitats and the related density increased significantly. Using conditional co-occurrence algorithms, we identified five indicator species (Mictyris brevidactylus, Macrophthalmus banzai, Uca arcuata, Uca lacteal and Uca borealis) with high co-occurrence probabilities, whose population responses provided direct evidence of the benefits of mangrove removal for wetland restoration. The results indicate that mangrove removal is an appropriate habitat rehabilitation strategy for benthic organisms, and that the chosen indicator species may provide valuable ecological information for coastal managers seeking to control the spread of mangroves. [ABSTRACT FROM AUTHOR]

Fouling plates (Plexiglas squares and concrete blocks) were bolted in a horizontal position to racks on the ocean floor at a depth of 12 m. Some of these were periodically taken from the sea, subjected to nondestructive microscopic survey in the laboratory, and then replaced. Others were: a) left undisturbed as controls; b) variously caged to exclude larger predatory animals; or, c) had sediment removed from them at intervals. Populations developing on the periodically surveyed plates were similar to those on undisturbed plates. Populations on undisturbed plates were significantly different from those on partially caged plates. The exclusion of large predators by complete caging resulted in highly significantly different communities from those on partially caged plates. Completely caged communities were composed mainly of worms, barnacles and bryozoans. Summer-installed plates supported significantly different populations at the end of the experimental period (12 mo) from winter-installed plates. Plant growth rates were slow, not exceeding 2 cm/mo, and the mortality rates were often high. A few species had high rates of recruitment and survival each month. Most had high recruitment only in the most favorable growth periods and high loss rates. Physical conditions on the sea floor were measured. The methods developed during this study make it possible to quantitatively describe the growth and reproduction of populations of benthic marine algae in the sea. [ABSTRACT FROM AUTHOR]

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In early 2018, a large easterly storm hit the East Anglian coast of the UK, colloquially known as the 'Beast from the East', which also resulted in mass strandings of benthic organisms. There were subsequent instances of dogs consuming such organisms, leading to illness and, in some cases, fatalities. Epidemiological investigations identified paralytic shellfish toxins (PSTs) as the cause, with toxins present in a range of species and concentrations exceeding 14,000 µg STX eq./kg in the sunstar Crossaster papposus. This study sought to better elucidate the geographic spread of any toxicity and identify any key organisms of concern. During the summers of 2018 and 2019, various species of benthic invertebrates were collected from demersal trawl surveys conducted across a variety of locations in the North Sea. An analysis of the benthic epifauna using two independent PST testing methods identified a 'hot spot' of toxic organisms in the Southern Bight, with a mean toxicity of 449 µg STX eq./kg. PSTs were quantified in sea chervil (Alcyonidium diaphanum), the first known detection in the phylum bryozoan, as well as eleven other new vectors (>50 µg STX eq./kg), namely the opisthobranch Scaphander lignarius, the starfish Anseropoda placenta, Asterias rubens, Luidia ciliaris, Astropecten irregularis and Stichastrella rosea, the brittlestar Ophiura ophiura, the crustaceans Atelecyclus rotundatus and Munida rugosa, the sea mouse Aphrodita aculeata, and the sea urchin Psammechinus miliaris. The two species that showed consistently high PST concentrations were C. papposus and A. diaphanum. Two toxic profiles were identified, with one dominated by dcSTX (decarbamoylsaxitoxin) associated with the majority of samples across the whole sampling region. The second profile occurred only in North-Eastern England and consisted of mostly STX (Saxitoxin) and GTX2 (gonyautoxin 2). Consequently, this study highlights widespread and variable levels of PSTs in the marine benthos, together with the first evidence for toxicity in a large number of new species. These findings highlight impacts to 'One Health', with the unexpected sources of toxins potentially creating risks to animal, human and environmental health, with further work required to assess the severity and geographical/temporal extent of these impacts. [ABSTRACT FROM AUTHOR]

Copyright of Umweltwissenschaften und Schadstoff-Forschung is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)