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Anthropogenic disturbance is known to be highly influential on ecosystems. Sensitive systems with a high ratio of specialized Fauna and Flora are often more affected than those inhabited with generalists. An example of a sensitive ecosystem is the mudflats located off List on the island of Sylt. To investigate the anthropogenic disturbance of the mudflats, we examined populations of Peringia ulvae and Corophium volutator. In this article we show that already a one-time disturbance of the mudflats leads to a significant reduction of density of P. ulvae. No significant difference could be observed between the area disturbed multiple times and the zone that was disturbed only once, indicating that a single disturbance has drastic effects on the ecosystem. Total numbers of C. volutator increased in zones that were disturbed compared to the control area. While organic mass did not significantly differ between disturbed and control area, disturbance, even a single one, resulted in a visual alteration and a decrease of net animal count.

The study assessed the environmental toxicity of three Norwegian mine tailings from Omya Hustadmarmor, Sydvaranger, and Sibelco, which are all released into a seawater recipient. Ecotoxicity assessments were performed on the overlying water extracted from the mine tailings, the transformation/dissolution waters obtained from the mine tailings, and whole sediment assessment using a suite of marine organisms including algae, Crustacea, and Mollusca. Overall, based on the toxicity evaluation of the transformation/dissolution data, Sibelco tailings resulted in the highest toxicity albeit at relatively high concentrations, followed by Sydvaranger and Hustadmarmor. Sibelco was the only mine where process chemicals were not used. In contrast, the Corophium sediment contact assay revealed a significantly higher toxicity exerted by Hustadmarmor tailings, which may indicate a physical impact of the fine tailings. The effects observed were discussed with respect to both the measured chemical concentrations of the tailings and the potential physical impact of the tailing particles on organism health.

Glyphosate-based formulations are the most commonly used herbicides worldwide with the risk of potential contamination of aquatic bodies. The present study assessed the response of four marine crustaceans to three different brands of herbicides Roundup®Platinum, Efesto® and Taifun® MK CL.T, under two selected temperatures of 20 °C and 30 °C. The harpacticoid copepod Tigriopus fulvus, the anostracan Artemia franciscana, the amphipod Corophium insidiosum and the isopod Sphaeroma serratum were chosen as testing organisms. Effects of herbicides and temperatures were assessed by estimating lethal concentrations. The results showed that the high temperature rises the toxicity of glyphosate with an increase of mortality of all the tested species. This is an important aspect for future risk assessments of pesticides under global climate change scenarios. Efesto® resulted the most toxic brand, showing C. insidiosum the most sensitive with 96 h-LC50 values of 3.25 mg/L acid equivalent (a.e.) at 30 °C and 7.94 mg/L a.e. at 20 °C followed by T. fulvus while A. franciscana and S. serratum were the less sensitive. This study provides important information for assessing the toxic effects of three different brands of glyphosate-based herbicides on non-target marine organisms suggesting that they should be carefully managed to minimize any negative impact on marine organisms.

The presence of products containing nanoparticles or nanofibers is rapidly growing. Nanotechnology involves a wide spectrum of industrial fields. There is a lack of information regarding the toxicity of these nanoparticles in aqueous media. The potential acute toxicity of ZnO NPs using two marine crustacean species: the copepod Tigriopus fulvus and the amphypod Corophium insidiosum was evaluated. Acute tests were conducted on adults of T. Fulvus nauplii and C. insidiosum. Both test species were exposed for 96 h to 5 increasing concentrations of ZnO NPs and ZnSO4H2O, and the endpoint was mortality. Statistical analysis revealed that the mean LC50 values of both ZnO NPs and ZnSO4H2O (ZnO NPs: F = 59.42; P < 0.0015; ZnSO4H2O: F = 25.57; P < 0.0015) were significantly lower for Tigriopus fulvus than for Corophium insidiosum. This result confirms that the toxic effect could be mainly attributed to the Zn ions, confirming that the dissolution processes play a crucial role in the toxicity of the ZnO NPs.

Burrowing benthic animals belonging to the same functional group may produce species-specific effects on microbially mediated nitrogen (N) processes depending upon different ecological traits. We investigated the effects of two tube-dwelling organisms, amphipods (Corophium insidiosum) and chironomid larvae (Chironomus plumosus), on benthic N cycling in bioturbated estuarine sediments. Aims of this work were to analyze the interactions among burrowers and N-related microbial processes in two distinct sedimentary environments colonized by benthic animals with different ecological traits. We hypothesized higher rates of nitrification and higher coupled nitrification–denitrification in sediments with C. insidiosum due to continuous ventilation rates. We expected higher denitrification of water column nitrate in sediments with C. plumosus due to lower and intermittent ventilation activity and lower oxygen levels in burrows. To this purpose, we combined process–specific (nitrification and denitrification) with net N flux measurements in intact and reconstructed sediments. Sediments with C. insidiosum had higher rates of oxygen demand and of potential nitrification and higher concentration of pore water NH4+ as compared to sediments with C. plumosus. Sediments with both species displayed comparable net N2 fluxes, mostly sustained by respiration of water column NO3− in sediments with chironomid larvae and by NO3− produced within sediments in sediments with corophiid amphipods. Corophium insidiosum stimulated nitrification nearly 15-fold more as compared to C. plumosus. Overall, our results demonstrate that sediments with burrowing fauna may display similar rates of denitrification, but underlying mechanisms may deeply vary and be species-specific.

Covert mortality nodavirus (CMNV) is the pathogen that has been identified as the cause of viral covert mortality disease (VCMD) in marine and brackish water shrimp. Recent outbreaks of this disease have resulted, and continue to result, in substantial production and economic losses to shrimp aquaculture producers in China and elsewhere. To explore potential vectors and reservoir hosts of CMNV, we collected fifteen species of invertebrates from shrimp ponds affected by VCMD. Samples were tested through the use of: reverse transcription loop-mediated isothermal amplification (RT-LAMP), reverse transcription nested PCR (RT-nPCR) followed by gene sequencing, histopathology, and in situ RNA hybridization (ISH). The results of RT-LAMP and RT-nPCR assay indicated that CMNV positive samples were identified in eleven species including brine shrimp Artemia sinica, a barnacle Balanus sp., the rotifer Brachionus urceus, the amphipod Corophium sinense Zhang, the Pacific oyster Crassostrea gigas, a hermit crab Diogenes edwardsii, the common clam Meretrix lusoria, a ghost crab Ocypode cordimundus, the hyperiid amphipod Parathemisto gaudichaudi, a fiddler crab Tubuca arcuata, and an unidentified gammarid amphipod. The alignment of CMNV RNA-dependent RNA polymerase gene sequences from eight of the species demonstrated high identities (97-100% in nucleotide sequence) with that from the original CMNV isolates of Penaeus vannamei, which suggests that these species could either be infected with, or acting as mechanical vectors of, CMNV. The CMNV infection in C. sinense, D. edwardsii, O. cordimanus Zhang, P. gaudichalldi, and T. arcuata results, to varying degrees, in vacuolation and necrosis of targeted tissues, as was verified by ISH. The infection of CMNV in these five species suggests that they might act as reservoir hosts of CMNV. The results indicate that the common species of invertebrates inhabiting shrimp ponds may constitute biological risk factors for CMNV outbreaks.

Este artículo contiene 14 páginas, 4 figuras, 7 tablas, 1 apéndice., [EN]We studied the habitat structure (macrofaunal assemblages and bottom types) and zonation patterns of 29 unvegetated shoreline strands along the 900-km coast of Catalonia (NW Mediterranean Sea). Organisms were sampled with grabs, pitfall traps, sticky traps, clam nets and spades to ensure capture of the different proportions of macrofaunal assemblages from the supra-, medio- and infralittoral levels. We collected 211 taxa: 194 animals and 17 algae. The most abundant and dominant organisms collected with van Veen grabs were Nematoda, Oligochaeta and Collembola at the supralittoral level; the polychaetes Saccocirrus spp. and Pisione remota, the amphipod Corophium orientale, Nematoda, and Turbellaria at the mediolittoral level; and Nematoda at the upper infralittoral level. SIMPER analysis revealed great dissimilarity between the organisms inhabiting the supralittoral and the other littoral levels. Regarding the epifauna, the sticky traps used at the supralittoral level mainly collected Collembola, which were nearly absent in pitfall traps. The qualitative study performed with a clam net and a small spade revealed that Nematoda, Saccocirrus spp., Turbellaria, Nemertea and the polychaete P. remota were the most abundant animals at both the medio- and the infralittoral levels and no differences were found between these levels. Different qualitative sampling methodologies showed that in fine sediments the bivalves Donax trunculus and D. semistriatus determined more than 97% of dissimilarity from coarse-sand sites. Richness increased in protected sandy and cobble shores. Littoral level and bottom-type features were only to a certain extent valid indicators of specific biotic components for a specific habitat. [ES]Se ha estudiado la estructura de los hábitats (comunidades de macrofauna y tipos de sedimento) y los patrones de zonación de 29 playas desprovistas de vegetación a lo largo de los 900 km de la costa de Cataluña (Mediterráneo noroccidental). El muestreo de los organismos se realizó mediante dragas, trampas de caída, trampas adhesivas, redes de marisqueo y palas para asegurar una captura exhaustiva de los organismos presentes en las comunidades de macrofauna de los niveles supralitoral, mediolitoral e infralitoral. Se colectaron 211 taxones: 194 animales y 17 algas. Los organismos más abundantes y dominantes recolectados con dragas van Veen fueron: Nematodos, Oligoquetos y Colémbolos en el nivel supralitoral; los poliquetos Saccocirrus spp. y Pisione remota, el anfípodo Corophium orientale, Nematodos y Turbelarios en el nivel mediolitoral; y Nematodos en la parte menos profunda del nivel infralitoral. Los análisis SIMPER detectaron grandes diferencias entre los organismos del nivel supralitoral y los de los otros niveles. Respecto a la epifauna, las trampas adhesivas usadas en el nivel supralitoral capturaron principalmente Colémbolos, los cuales estaban ausentes en las trampas de caida. El estudio cualitativo realizado con una red de marisqueo y una pala pequeña reveló que Nematodos, los poliquetos Saccocirrus spp. y Pisione remota, Turbelarios y Nemertinos eran los animales más abundantes tanto en el nivel mediolitoral como en el nivel infralitoral y que no había diferencias entre ambos niveles. Diferentes métodos cualitativos de muestreo revelaron que en los sedimentos finos los bivalvos Donax trunculus y D. semistriatus determinaban más del 97% de la disimilitud con los sedimentos gruesos. La riqueza en especies aumentaba en playas mixtas de arenas y cantos. El nivel y el tipo de sedimento fueron solo hasta cierto punto indicadores válidos de la composición de especies para cada hábitat concreto., Financial support came from the projects “Cartografia dels Hàbitats Litorals a Catalunya” (Departament de Territori i Sosteniblitat and Institut Cartogràfic, Generalitat de Catalunya) and INTRAMURAL CSIC 201330E065.

We investigated the nine heavy metal contents in the sediments and macrobenthos of the Yellow River Delta Wetlands using three experimental areas that received freshwater releases and one reference area that did not. Heavy metal contents, the single-factor contamination index (SFCI), the metal contamination index (MCI), and the biota-sediment accumulation factor (BSAF) were used to evaluate the potential ecological risk and bioaccumulation. We found that As exceeded the national standard value by more than 50%, and that the ranges of SFCI for each metal were generally larger in autumn than in spring. MCI showed no clear pattern, but the BSAF results suggest that Cd bioaccumulates from sediments to macrobenthos. Pollution-resistant species such as Corophium sinense, Chironomus sp., and Einfeldia sp. became dominant in the areas receiving freshwater releases, and provide direct evidence of ecological risk in the wetlands. Our results provide preliminary information to guide managers for ecological risk assessments.

This study describes the ecology of mesozooplankton in the shallows of the large central basin area of the Swan-Canning Estuary on the microtidal lower west coast of Australia during the mid-1980s when, as in most other south-western Australian estuaries, it was mesotrophic. As the vast majority of species reproduce within the estuary and there is a lack of a net upstream flow of bottom water during each tidal cycle to facilitate selective tidal transport, the populations of those species are considered autochthonous. Species restricted to the estuary accounted for 63% of the total number of species and 83% of abundance. Contributions by tychoplankton to total number of species (68%) and individuals (59%) exceeded the corresponding values of 18 and 39% for holoplankton and 14 and 2% for meroplankton. Low meroplankton values result from a paucity of benthic macroinvertebrate species with planktotrophic development. Comparisons with data for the shallow basin areas of the nearby highly eutrophic Peel-Harvey Estuary were used to indicate how mesozooplankton in the microtidal estuaries respond to excessive nutrient enrichment. The mean number of species in the Swan-Canning was essentially the same as in the Peel-Harvey, whereas concentrations were only half, reflecting the lower productivity of the former estuary. However, concentrations of the four most abundant species in the Swan-Canning, the amphipod Grandidierella propendatata, the calanoids Gladioferens imparipes and Acartia cf. clausi and a harpacticoid species, exceeded those of these species in the Peel-Harvey by between 1.6 and 11.7 times. Greater concentrations in the Swan-Canning were attributable to this mesotrophic system not undergoing the reduction in oxygen concentrations and/or environmental degradation, to which these species are susceptible. In contrast, concentrations of the amphipods Corophium minor and Tethygenia elanora and large nematodes, which are tolerant of degraded environmental conditions, were greater in the Peel-Harvey. Holoplankton made a far greater contribution in the Swan-Canning than Peel-Harvey, due to substantial numbers of copepods that benefit from good environmental conditions. Mesozooplankton composition in both estuaries underwent cyclical changes during the year due to time-staggered differences in seasonal concentrations of various species. Cyclical changes and variations in composition were more closely related to measured environmental variables in the Swan-Canning than Peel-Harvey estuaries. The concentrations of many species were greater at night than during the day presumably reflecting a nycthemeral response and/or low nocturnal oxygen concentrations at the bottom of the water column.

Sunscreens can induce ecotoxicological effects and may cause significant impacts in the aquatic ecosystem. In spite of that, ecotoxicological responses of key marine species to sunscreens are scarcely studied in Mediterranean ecosystems, and literature data are lacking. Furthermore, changes in water salinity induced by global warming could significantly affect the ecotoxicological responses of marine species exposed to sunscreens. This research focuses on the evaluation of ecotoxicological responses of Phaeodactylum tricornutum (algae), Corophium orientalis (macroinvertebrate), and Paracentrotus lividus (echinoderms) exposed to sunscreens, which include both chemical- and physical-based. This study, also, analyzes the changes in ecotoxicological responses of the tested species linked to increase in salinity. Results showed that salinity stress significantly increases the toxicity of sunscreens on the tested marine species. Physical-based sunscreens resulted in more toxicity at higher salinity than chemical-based ones toward C. orientalis and P. tricornutum. This study evidenced that risk classifications of sunscreens recorded under standard salinity conditions could be significantly different from that recorded in the natural environment under salinity stress. The collection of a complete dataset on the ecotoxicological effects of sunscreens on marine species tested under salinity stress could be useful to correctly weigh risks for the marine environment under possible future ecological changing scenarios following the global changing driver.

The Mar Piccolo of Taranto (Ionian Sea, Southern Italy) is a semi-enclosed and strongly polluted basin. For decades, it has been subjected to different anthropogenic impacts. These stressors caused severe sediments contamination with high concentration of different pollutants (PAHs, PCB, heavy metals). In order to assess the current status of sediments contamination, an ecotoxicological investigation combined with chemical analysis (heavy metals, PAH, and PCB) has been performed. In order to derive ecologically relevant conclusions, a multiorganisms and multiend-points approach has been applied, exposing organisms from different trophic levels to elutriate and whole sediment. The battery of bioassays consists of a microalgal growth inhibition test (Dunaliella tertiolecta), acute and sublethal assays (end-points: mortality, immobilization and swimming speed alteration) on crustaceans larvae and juveniles, and rotifers (Amphibalanus amphitrite, Artemia salina, Corophium insidiosum and Brachionus plicatilis), and embryotoxicity test on echinoderms (Paracentrotus lividus). Considering the high levels of sediment contamination highlighted from chemical analysis, an unexpected very low toxic effect was observed, even considering the sublethal end-point (larval swimming speed alteration). The results of this study suggest a very complex contaminants dynamic in the Mar Piccolo sediments that, despite a strong level of contamination, seems to not affect in a proportional manner the biological compartment.

The International workshop on Integrated Assessment of CONtaminants impacts on the North sea (ICON) provided a framework to validate the application of chemical and biological assessment thresholds (BACs and EACs) in the Seine Bay in France. Bioassays (oyster larval anomalies, Corophium arenarium toxicity assay and DR Calux) for sediment and biomarkers: ethoxyresorufin-O-deethylase (EROD) activity, acetylcholinesterase (AChE) activity, lysosomal membrane stability (LMS), DNA strand breaks using the Comet assay, DNA adducts, micronucleus (MN), PAH metabolites, imposex, intersex and fish external pathologies were analysed in four marine sentinel species (Platichthys flesus, Limanda limanda, Mytilus sp. and Nucella lapilus). Polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and heavy metals were analysed in biota and sediment. Results for sediment and four species in 2008–2009 made it possible to quantify the impact of contaminants using thresholds (Environmental Assessment Criteria/EAC2008: 70% and EAC2009: 60%) and effects (EAC2008: 50% and EAC2009: 40%) in the Seine estuary. The Seine estuary is ranked among Europe's most highly polluted sites., SI

article i nfo The present study aimed to investigate the feeding ecology and influence of prey-predator interactions on juve- nile flounderPlatichthys flesusinanAtlanticestuarinenurseryarea(Limaestuary,NWPortugal),focusingonprey selection and ontogenetic shifts in the diet. The relationship between prey availability and flounder distribution was also investigated. Juvenile flounder diet included 21 taxa of macroinvertebrates and fishes, sand and plant debris. According to numerical, occurrence, and gravimetric dietary indices, macroinvertebrates, namely Chiron- omidae and Corophium spp. were the main prey items. The diet diversity tended to increase as juveniles grew, although some dietary overlap occurred between the early juveniles (50-149 mm total length (TL)). In fact, the diet diversity of the newly settled juveniles (b50 mm TL) was particularly low, evidencing the importance of Chironomidae. Moreover, an ontogenetic shift was evident, since older juveniles (1 + ) presented a distinct diet, including new items absent from the diet of the 0 + juveniles, namely Teleostei, Carcinus maenas ,a nd Nemertea. The juvenile flounder presented an overall generalist behavior, feeding on the most abundant macro- invertebratesnamelyChironomidaeandCorophiumspp.,asevidencedbytheStrausslinearindex.Thespatialdis- tribution of the 0 + flounder in the Lima estuary was associated with salinity and prey (Chironomidae and Corophium spp.). These preys were characteristic of the upper estuary where most of the juveniles, especially the newly settled, were found. Hence, this study reinforces the importance of both abiotic and biotic factors as environmental driven controls of habitat use during the early phases of the demersal life of European flounder. © 2014 Elsevier B.V. All rights reserved.

The Gross growth efficiency (GGE) is defined as the amount of consumer carbon produced relative to the amount of prey ingested in a given time interval. In population ecology, it can be considered as an index for the ability of a consumer to convert the biomass of food into its population production. In this study, it was firstly applied to estimate the role of amphipods grazing in the biomass dynamics of macroalgae (Ulva lactuca) in Yundang Lagoon (a subtropical eutrophic coastal lagoon, Xiamen City, China). It was found that amphipods were the dominant group (82.2%–98.7%) in the benthic assemblage, in which five amphipod species (Corophium uenoi, Ampithoe valida, Grandidierella japonica, Grammaropsis laevipalmata and Caprella panantis) were observed in the lagoon. However, only A. valida significantly consumed U. lactuca among these amphipod species. A series of experiments were conducted to estimate the consumption of U. lactuca by A. valida. It was suggested that the monthly secondary production (P) of A. valida using size frequency method ranged from 2.39 to 13.68 g/m2. GGE of A. valida exponentially reduced with body size and was closely associated with water temperature. Therefore, GGE equation for different months using the temperature recorded during the field investigation was fitted. The monthly consumption of U. lactuca was figured out to be 86.7–1 549.0 g/m2 by the sum of consumption (P/GGE) by A. valida at different size, accounting for 2.0%–37.5% of U. lactuca production. It indicates that the grazing effect of A. valida did play a role in reducing the accumulation of U. lactuca biomass when A. valida was abundant, but it finally fails to limit the U. lactuca growth in Yundang Lagoon. Low abundance of A. valida and high nutrient loading may be two major reasons for the outbreak of U. lactuca bloom in the lagoon.

The macrobenthic community was compared at four sites characterized by varying degrees of freshwater input, organic enrichment and confinement in the Cabras lagoon (Sardinia, Italy). Three sites, riverine (Cl), confined (C2) and seaward (C3), were studied on two dates of summer 2010 and on two dates of winter 2011. A fourth site (C12), representative of the central sector of the Cabras lagoon, was included in this study using the extensive historical datasets at our disposal from previously published work. We aimed to test the hypothesis that (1) the benthos is distributed according to the recently proposed concept of habitat saprobity for coastal lagoons that unifies the Pearson Rosenberg (sensu organic enrichment) and Guelorget-Perthuisot (sensu confinement) models, and (2) indicator species of different saprobic levels can be identified among dominant species occurring along the saprobity gradient. Salinity was also considered as an additional agent of selection in brackish environments. Irrespective of significant seasonal changes within each site, our results highlighted major environmental and biotic differences between sites. At the northward riverine site (Cl), most affected by freshwater input and with limited organic matter (OM) enrichment, Corophium orientate was the single dominant species. The most confined site (C2) was characterized by the highest levels of sedimentary OM and benthic Chlorophyll-a and by mesohaline conditions; the site was inhabited mainly by the halolimnobic Hediste diversicolor and Hydrobia spp. Site C12, characterized by a high OM load and high residence time, was dominated by the opportunistic detritivorous Alitta succinea and Polydora ciliata. At the southern-most seaward site (C3) the considerable seawater renewal, resulting in high salinity (only in summer) and limited OM load, favored a much more diverse macrobenthic assemblage, essentially composed of both marine species, such as Corophium insidiosum, Gammarus aequicauda, and brackish-water species, such as Lekanesphaera hookeri and Idotea chelipes. We conclude that the biotic and abiotic characteristics of the Cabras lagoon can be represented by a succession of spatial zones along two main gradients determined by salinity and saprobity. The salinity gradient proved to be the main structural feature in the oligohaline pole, while in the range of variable salinity, saprobity appeared to be the main selection factor. To illustrate our findings, we provide a graphical representation summarizing the changes in environmental parameters and indicator species along the salinity and saprobity gradients. (C) 2014 Elsevier Ltd. All rights reserved.

The feeding habits of Tridentiger bifasciatus were studied using 733 individuals collected in the tidal creek at Sangnae-ri, Suncheon, Korea, using a push net, monthly, from April 2011 to March 2012. The standard length (SL) of the specimens ranged from 1.5 to 8.2 cm. The stomach content analysis indicated that T. bifasciatus consumed mainly amphipods, such as Corophium sp., while copepods, polychaetes, and shrimps were other important prey species. In addition T. bifasciatus ate small quantities of crab larvae, fish, gastropod larvae, and insects. T. bifasciatus is a generalist that feeds on various zoobenthos, including fish. T. bifasciatus underwent an ontogenetic dietary shift. Smaller individuals (1-2 cm SL) fed mainly on amphipods. The proportion of amphipods decreased as body size increased, whereas the consumption of polychaetes increased gradually. The seasonal variation in the diet composition of T. bifasciatus was significant. Insects were common prey during summer, while the amounts of other prey, including polychaetes, were similar during spring, autumn, and winter.

We examined prey availability, prey consumed, and diet energy content as sources of variation in growth of natural fall Chinook Salmon Oncorhynchus tshawytscha subyearlings rearing in riverine and reservoir habitats in the Snake River. Subyearlings in riverine habitat primarily consumed aquatic insects (e.g., Diptera, Ephemeroptera, Trichoptera), of which a high proportion was represented by adult, terrestrial forms. In the reservoir, subyearlings also consumed aquatic insects but also preyed heavily at times on nonnative lentic amphipods Corophium spp. and the mysid Neomysis mercedis, which were absent in riverine habitats. The availability of prey was typically much higher in the reservoir due to N. mercedis often composing over 90% of the biomass, but when this taxon was removed from consideration, biomass estimates were more often higher in the riverine habitat. Subyearling diets during 2009–2011were generally 17–40% higher in energy in the riverine habitat than in the reservoir. Observed grow...

In marine ecosystems, benthic organisms are really important because they are the first step in the transfer of contaminants from environment to biota. To this end, this study focused on biological assays with the amphipod Corophium orientale exposed to two different molecules of arsenic: arsenate (AsV), the most abundant form in sediments, and dimethyl-arsinate (DMA), expected to be moderately toxic as an intermediate in the process of detoxification. The toxicity of arsenic compounds was measured after exposure to three different matrices: water, spiked natural sediment and inert spiked quartz sand. LC50 values were calculated for each exposure, and the results confirmed the highest toxicity of AsV, in addition to underlining the importance of matrix of exposure. Water exposure was the matrix which presented the highest toxicity for inorganic arsenic (AsV LC50=3.51 mg L−1 vs DMA LC50=54.65 mg L−1), spiked natural sediment demonstrated its capability to chelate arsenate toxicity (AsV LC50=34.27 mg kg−1 v...

Although copper (Cu) is an essential element for life, leaching from boat paint can cause excess environmental loading in enclosed marinas. The effects of copper contamination on benthic macrofaunal communities were examined in three San Diego Bay marinas (America’s Cup, Harbor Island West and East) in Southern California, USA. The distribution of Cu concentration in sediments exhibited a clear spatial gradient, with hotspots created by the presence of boats, which in two marinas exceeded the effect range medium (ERM). Elevated sediment Cu was associated with differences in benthic assemblages, reduced species richness and enhanced dominance in America’s Cup and Harbor Island West, whereas Harbor Island East did not appear to be affected. At sites without boats there were greater abundances of some amphipods such as the species Desdimelita sp., Harpinia sp., Aoroides sp., Corophium sp., Podocerus sp., bivalves such as Lyonsia californica, Musculista senhousia, Macoma sp., and polychaetes such as Diplocirrus sp. In contrast, at sites with boats, densities of Pseudopolydora paucibranchiata, Polydora nuchalis, Euchone limnicola, Exogone lourei, Tubificoides spp. were enhanced. The limited impact on Harbor Island East suggests not only lower Cu input rates and increased water flushing and mixing, but also the presence of adequate defense mechanisms that regulate availability and mitigate toxic impacts. At all three marinas, Cu in tissues of several macrobenthic species exhibited Cu bioaccumulation above levels found in the surrounding environment. The annelids Lumbrineris sp. and Tubificoides spp., and the amphipod Desdimelita sp. contained high levels of Cu, suggesting they function as Cu bioaccumulators. The spionid polychaetes Polydora nuchalis and Pseudopolydora paucibranchiata had much lower Cu concentrations than surrounding sediments, suggesting they function as Cu bioregulators. The macrobenthic invertebrates in San Diego Bay marinas that tolerate Cu pollution (e.g. P. nuchalis, P. paucibranchiata, Euchone limnicola, Typosyllis sp., Tubificoides sp.) may function as indicators of high-Cu conditions, whereas the presence of Cu-sensitive species (e.g. Podocerus sp., Aoroides sp., Harpinia sp., Macoma sp., Lyonsia californica) may indicate healthier conditions (less Cu-stressed). Parallel responses by faunas of Shelter Island Yacht Basin, also in San Diego Bay, suggest potential for development of regional Cu contamination assessment criteria, and call for functional comparisons with other marinas and coastal water bodies.

This study was conducted to get some basic information on the community structure of macrozoobenthos and its temporal change at 3 sites on the Gapo artificial tidal flat within Masan Bay from March 2002 to April 2004 when 8 years passed after the construction. The Gapo artificial tidal flat was constructed by filling the dredged contaminated sediments of MasanBayfrom 1990 to 1993. The surface sediment consisted of fine particles, but the grain size at the tidal flat has changed from mud to muddy sand by adding coarse particles for manila clam aquaculture by local fishermen from 2002. A total of 35 faunal species including 23 species at the upper tidal flat, 28 species at the lower tidal flat and 30 species in the tidal channel were collected during the study period. Polychaete worms were the most dominant fauna in species number and total faunal density, but mollusks were the most dominant in biomass. There was a specific species composition along tidal level. At the upper tidal flat, Prionospio japonicus, Sigambra tentaculata, and Neanthes succinea were dominant and at the lower tidal flat, N. succinea, P. japonicus, Corophium sinensis, and Ruditapes philipinarum were dominant while S. tentaculata, Paraprionospio coora, and C. sinensis were dominant at the tidal channel. In the feeding guild composition of the community, the surface deposit feeder (SDF) was the most abundant functional group followed by carnivores. The abundance and biomass showed a seasonal fluctuation; they decreased during summer seasonal and recovered in autumn. The Benthic Pollution Index (BPI) reflecting the trophic composition of macrozoobenthic community at each site remained in a very low level during most study period, which indicates the macrobenthic community of the Gapo artificial tidal flat has been in a disturbed environmental condition. The MDS plots also indicated that the species composition has changed seasonally and a large change in it was shown from spring to summer at all three stations. These results indicated that the benthic community in the constructed mud flat area has not reached on a stable structure until the spring of 2004 for 10 years after the artificial tidal flat construction.

For more than 100 years, the Werra River has been severely affected by intensive salinisation caused by potash fertilizer industries. We show considerable differences in macroinvertebrate assemblages between reaches without salinisation impact and downstream reaches with intense anthropogenic salinisation in the Werra. This is true for almost all biological metrics relevant for ecological status classification under the EU-Water Framework Directive (EU-WFD) (European Community, Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy, No. L 327/1, of 22 December 2000) and diversity measures (taxon richness, evenness). Macroinvertebrate assemblages at salinisation sites were completely dominated by three halophile neobiotic macroinvertebrate species (Gammarus tigrinus, Corophium lacustre and Potamopyrgus antipodarum). We compared anthropogenically salinised sites from the Werra with disturbed but non-salinised sites from the Werra and other German rivers. We used biological metrics developed for classifying the ecological status according to the EU-WFD. This comparison indicated a severe degradation at salinisation sites on the Werra and these fell into the worst ecological status class ‘bad’ according to the EU-WFD. Multivariate statistical analyses revealed anthropogenic salinisation as a key factor causing the differences in composition of macroinvertebrate assemblages in the Werra between salinisation and reference sites. Analyses of the long-term presence–absence data of macroinvertebrate assemblages indicated no marked improvement in the ecological status in the past 20 years.

The diet and population structure of larval and early juvenile Glossogobius callidus and Redigobius dewaali (Gobiidae) were examined from the headwater region of the permanently open Great Fish Estuary along the south-east coast of southern Africa. Stomach contents of five selected size classes were sorted and identified to the lowest possible taxonomic level for each goby species. Using % Index of Relative Importance values, ontogenic shifts and dietary breadth were determined for each species as was dietary overlap between species. Numerically, both gobiid species showed similar temporal and spatial trends. Seasonal differences in catches were evident, although no numerical differences across sampled sites were found. A large degree of dietary overlap was found between the two species. The zooplanktonic diet showed a greater degree of ontogenic shift in R. dewaali than G. callidus, although similar trends were found for both. In both goby species, Calanoid sp. (Copepoda) generally decreased in importance across size classes, being the most important in the smallest size class whilst Corophium sp. (Amphipoda) increased in importance across size classes, being the least important at the smallest size classes. For both G. callidus and R. dewaali, Insecta contributed significantly to at least one of the five size classes. The larger size classes showed the least dietary overlap and the highest niche breadth. In addition, as is the case in many gobiids worldwide, the larger size classes of both sampled gobiid species consumed a broader prey size range. In conclusion, dietary overlap was largely similar between the young gobiids, suggesting that either food resources are not limiting, or niche separation is attributed to differences in foraging strategies. Ontogenic dietary shifts were however present for both gobiids with regard to prey items and prey size, suggesting a greater degree of foraging niche separation in adults of the species.

Quantitative and qualitative sampling of zoobenthos was carried out in October 2004 and October 2009 to assess the ecological influence of a reclamation project on the macrobenthos of an East Nanhui tidal flat.The surveys were conducted each year in four sections: S1—S2 and S3—S4 were inside and outside the dyke,respectively,in 2004,while T1-T3 and T4 were inside and outside the dyke,respectively,in 2009.In total,32 species were found across all areas in 2004,Twenty of these species occurred inside the dyke and 21 species occurred outside the dyke.Twenty-six species were found in 2009 whit nine species inside the dyke and 19 species outside the dyke.On both sampling occasions,most of the macrobenthos were euryhaline species and the rest were freshwater species.From 2004 to 2009 species abundance of Crustacea,Mollusca and Polychaeta exhibited a clear decline inside the dyke,while aquatic insect abundance increased to there species inside the dyke.Outside the dyke,Crustacea and Polychaeta decreased between 2004 and 2009 but Mollusca increased by five species.In 2004,there ere eight dominant species inside the dyke,namely: Corophium sinensis,Uca arcuata,Sesarma dehaani,Ilyoplax deschampsi,Assiminea latercea,Cerithidea sinensis,Capitella capitata and Rhуacodrilus sinicus.Four species were dominant outside the dyke: Corophium sinensis,Ilyoplax deschampsi,Momoculodes limnophilus and Bullacta exarata.Corophium sinensis and Ilyoplax deschampsi were common dominant species.In 2009,Chironomid larvae were the dominant species inside the dyke and Assiminea latercea,Elachisina sp.,Glauconome chinensis and Heteromastus filiformis were the four dominant species outside the dyke.The average abundances and biomass values for macrobenthos were 44.15 ind/m2 and 38.80 g/m2 in 2004 and 86.76 ind/m2 and 1.97 g/m2 in 2009.Macrozoobenthos biomass decreased significantly between 2004 and 2009,although abundance did not decline.Data were analyzed using SPSS,one-way ANOVA,hierarchical cluster analysis and non-metric multidimensional scaling(MDS).The results of cluster analyses and MDS indicated that the eight sections were divided into four groups with different macrobenthic communities: the first group included four sections,S1-S4 from 2004;the second group included T1 and T2 from 2009,which were statistically very different from S1 and S2;while the last two groups were T3 and T4.The structure of the macrobenthic community in T4 was very similar to that in S3.T3,on the other hand,was subjected to frequent human disturbance generating a greater level of habital heterogeneity. Reclamation is an important factor of changing macrobenthic communities.In this study,the composition of dominant species changed markedly with a clear decline in species diversity(Shannon-Weiner index,Pielou′s evenness index,species richness and Simpson′s diversity index).The lowest diversity index was recorded in the reclaimed area.Reclamation on tidal flats changes salinity,tidal action and tidal flat sediment characteristics and dynamics.Human activities have a major impact on zoobenthos communities.Ecological restoration following reclamation projects is essential and may include building water gates,or restocking with macrobenthos and native plant species that can adjust and survive in the new environment.

Ostreopsis cfr. ovata toxicity was estimated through acute bioassays using four crustacean species (Artemia franciscana, Tigriopus fulvus, Corophium insidiosum and Sphaeroma serratum). The epiphytic dinoflagellate showed significant toxicity towards all tested crustaceans, which have usually exhibited the highest mortalities with increasing the dinoflagellate cell concentrations. Furthermore, our results evidenced a higher sensitivity of A. franciscana larvae to Ostreopsis, compared with the other species. The results of our bioassays highlighted the usefulness of employing a base-set of different species rather than one derived from a single species, in order to obtain more reliable information on the algal toxicity.

Sediments are an ecologically important component of the aquatic environment and may play a key role in mediating the exchange of contaminants between particulate, dissolved, and biological phases. For a comprehensive assessment of potential sediment toxicity, the use of a single species may not detect toxicant with a specific mode of action. Therefore it is advisable to carry out ecotoxicological tests on a base-set of taxa utilizing test species belonging to different trophic levels. This paper describes the ecotoxicological evaluation of marine sediments from seven sites of Mar Piccolo estuary (Southern, Italy), four of them were located in the first inlet and three in the second inlet of Mar Piccolo estuary. Sediment samples from a site in Taranto Gulf were used as control sediment. Dunaliella tertiolecta, Tigriopus fulvus, Mytilus galloprovincialis, and Corophium insidiosum, were employed to identify the quality of sediments. The integration of biological tests results showed that all sampling sites located in the first inlet of Mar Piccolo were identified as toxic, according to all tests, while the sites of second inlet were found not toxic. The results obtained in this study indicate that the use of a battery of biological tests have important implications for risk assessment in estuarine e coastal waters.

Spatial structuring in species distribution can be caused by effects of biotic or abiotic factors on the vital rates (survival, growth or reproduction) or movement of individuals. Here, we studied the distribution patterns of a dominant infaunal invertebrate, the amphipod Corophium volu- tator, on an intertidal mudflat and evaluated the relative contribution of vital rates and movement on the formation of intermediate-scale patterns (10 to 100 m). We found a clumped distribution at scales ranging from 0.2 to 100 m and occasionally the presence of large-scale gradients. At intermediate scales, variation in density in the mud associated better with variation in movement variables (den- sity of swimmers and immigration) than demographic variables. Predictions from local population models not including migration often largely underestimated increases in local density, leaving immi- gration as the only mechanism explaining variation in density. Amphipod swimming was directed, and the direction of swimming corresponded to overall density gradients observed on the mudflat. We concluded that movement of C. volutator is an important process causing and maintaining inter- mediate-scale distribution patterns. Spatial variability in supply of individuals, likely linked to timing of swimming coupled with hydrodynamic conditions, translates into notable variation in population density distributions.

Invertebrates in soft-bottom marine communities exhibit a range of responses to predators and competitors, including both emigration and avoidance. Corophium volutator (Pallas), a burrowing amphipod abundant in the upper Bay of Fundy, Canada, frequently interacts with the eastern mudsnail, Ilyanassa obsoleta (Say), as both species utilize similar habitats and food resources. Typically these interactions result in negative effects on C. volutator. There is evidence that Corophium species exhibit avoidance behaviour when interacting with other species, but whether such a response occurs in the presence of I. obsoleta is unknown. To investigate C. volutator response to I. obsoleta, total C. volutator abundance and vertical distribution within the sediment was examined in a field experiment involving I. obsoleta enclosures and exclosures at two mudflats in the upper Bay of Fundy. I. obsoleta densities were manipulated between June and August 2008 and their effects on C. volutator abundance and vertical distribution observed. Results varied between mudflats and C. volutator size classes. At Peck's Cove, total C. volutator abundance was largely unaffected by I. obsoleta. No size class exhibited a distribution shift in response to I. obsoleta, though both mid-sized individuals and adults occupied deeper layers of sediment late in the summer. Abundance of C. volutator in all size classes at Grande Anse was reduced in July in direct proportion to exposure to I. obsoleta, and adults occupied higher sediment layers in July when I. obsoleta were excluded, suggesting that I. obsoleta curtailed use of these upper layers. Juvenile abundance rebounded in August, possibly due to the mass dispersal of a newly produced juvenile cohort. Adults were reduced in all treatments in August, probably as a result of normal seasonal mortality. Differences in C. volutator responses between mudflats highlight the site-specific nature of such interactions.

The intertidal and subtidal soft-bottoms of the inner area of the Ria de Vigo (NW Spain) were sampled in November and December 1999, and spatial distribution of crustacean species was examined. Environmental variables from water and sediment were measured at each sampling site. Amphipods and myocopids were the numerically dominant orders (49.9 and 26.9% dominance), amphipods accounting for more than 54% of identified taxa. The highest crustacean densities occurred with 55-41 species and 5953.6-4346.4 ind. m–2 in external areas, where the diversity index reached the maximum values. Multivariate techniques revealed that distribution of crustaceans in the inlet was highly dependent on depth. Ordination analysis determined three major assemblages: Intertidal bottoms colonized by seagrasses and subjected to strong variations of salinity were dominated by the amphipod Melita palmata, harpacticoids and the isopod Idotea baltica (Group A). The amphipod Corophium cf. runcicorne and the cumacean Iphinoe tenella predominated in the muddy bottoms of central areas (Group B). These species were also present in the deep muddy bottoms of the mouth of the inlet, with high carbonate and gravel contents, and with the myocopids and the amphipod Microdeutopus cf. armatus displaying maximum dominances (Group C). Los fondos blandos intermareales y submareales de la parte interna de la Ría de Vigo (NO España) fueron estudiados en relación a la distribución de los crustáceos y a las variables ambientales asociadas a sus aguas y sedimentos. Los anfípodos y miocópidos fueron los órdenes más abundantes (49.9 y 26.9%), presentando los anfípodos más del 54% de los taxa identificados. Las mayores densidades de crustáceos aparecieron en las áreas externas, con 55-41 especies y 5953.6-4346.4 individuos por m2, alcanzándose aquí los máximos valores de diversidad. Se emplearon técnicas multivariantes para analizar los datos, demostrando que la distribución de los crustáceos en la ensenada dependía principalmente de la profundidad. Se observaron tres principales asociaciones de crustáceos: Los fondos intermareales, colonizados por las fanerógamas marinas Zostera marina y Z. noltii y sometidos a drásticos cambios de salinidad, estuvieron dominados por el anfípodo Melita palmata, los harpacticoideos y el isópodo Idotea baltica (Grupo A). El anfípodo Corophium cf. runcicorne y el cumáceo Iphinoe tenella predominaron en los fondos fangosos de la zona central (Grupo B). Estas especies también estuvieron presentes en los fondos profundos de la boca de la ensenada, donde los miocópidos y el anfípodo Microdeutopus cf. armatus presentaron sus máximas dominancias (Grupo C).

Studies on secondary production lead to a better understanding of the functions of the macrobenthic ecosystem. Based on the macrobenthic data obtained at 6 sampling stations from April 2006 to January 2007, Brey’s (1990) empirical formula was applied to calculate the secondary production of macrobenthos in the mangrove area of Tong’an Bay. The results showed that the mean annual secondary production of macrobenthos was 13.24 gAFDW·m−2·a−1. The mean secondary production in the mangrove habitat was 12.22 gAFDW·m−2·a−1, lower than that in the non-mangrove habitat, which was 15.29 gAFDW·m−2·a−1. Two possible reasons existed for this difference. First, mollusk and crustacean, which contribute more to the secondary production, probably benefit from longer inundation period in the non-mangrove habitat. Second, the higher organic matter in the mangrove habitat results in hypoxia in the bottom sediment, which may decrease the secondary production. The annual mean production-to-biomass (P/B) ratio in Tong’an Bay was 1.17, with a ratio of 1.27 in the mangrove habitat and 0.96 in the non-mangrove habitat, which was coincident with the much higher density of Limnodriloides sp. and Corophium sp. in the mangrove habitat than in the non-mangrove habitat. The maximum secondary production and P/B ratio of macrobenthos both appeared at sampling station FL2 in April, 2006 (namely April-FL2) with values of 31.38 gAFDW·m−2·a−1 and 2.20, respectively. The macrobenthic secondary production in Tong’an Bay is lower than those in other intertidal studies except that in Haitan Strait, the reason being the different sediment properties. The P/B ratio in Tong’an Bay was the lowest due to the high proportion of crustaceans in the macrobenthic community.

The brackish water amphipod Corophium orientale is the dominant macroinvertebrate species in the upper Mira estuary, a small mesotidal system located in the southwest coast of Portugal. As climate changes will increase the frequency and intensity of extreme events such as floods and droughts, these will have a negative effect on benthic estuarine invertebrates, namely C. orientale. In order to understand the effects of these events on C. orientale, a dynamic model, based on published information and calibrated with field data, was developed and different scenarios were tested. For model construction, the annual development of three cohorts of C. orientale, their growth rates, and the establishment of the timing of each cohort rise and extinction are introduced. This structure can be repeated indefinitely, for years, and few parameters are required. The model simulations highlight the need for refuge areas that enable a fast recovery of the amphipod population after an extreme event and the recolozination of the affected areas.

The caprellid amphipod Caprella mutica became rapidly established in the North Sea, on the west coasts of Scotland and Ireland, the Irish Sea and English Channel. The first record for C. mutica from Jade Bay, in the southern North Sea, is reported here. High densities exceeding three-hundred individuals per wood panel (approximately 7000 ind./m -2 ) were found on wooden settlement panels in August/September 2009 associated with the tube-building amphipod species Jassa marmorata and Corophium acherusicum. The extensive mud-tube colonies of J. marmorata and C. acherusicum on the panels provide a suitable habitat for C. mutica attachment.

Conservation and management of coastal lagoons envisage direct human intervention. To prevent siltation and to preserve the hydrodynamics features of the lagoon system, the inner channels undergo regular maintenance dredging. Sediment properties (RDP, organic matter, grain size), trace metals (Cd, Cu, Cr, Hg, Ni, and Pb), and toxicity vs. the amphipod Corophium insidiosum and the luminescent bacterium Vibrio fischeri, were analysed before and after dredging operations in a coastal lagoon (Pialassa Baiona, Italy). To detect the actual impacts, disturbed sites were contrasted with multiple controls in two distinct times, i.e. before and after disturbance, according to a sampling design based on Beyond BACI principles. The integrated methodology here adopted suggests that dredging operations carried out are not likely to pose dramatic effects on environmental quality of the lagoon.