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Microplastics have accumulated in the environment since plastic production began, with present-day observations that range from marine trenches to mountains. However, research on microplastics has only recently begun so it is unclear how they have changed over time in many oceanic regions. Our study addressed this gap by quantifying the temporal and spatial dynamics of microplastics in two deep-water regions of the Gulf of Mexico (GOM). We isolated agglutinated foraminifera from sediment cores and assessed microplastics that were incorporated into their tests. Our results indicated that microplastics were incorporated by agglutinated foraminifera after plastic production began. Microplastics were higher at deep-water sites and closer to the Mississippi River. This study confirms the presence of microplastic incorporation into agglutinated foraminifera tests and investigates microplastics in deep-water sediments in the GOM. Additional work is needed to fully identify the distribution of microplastics across the GOM and other oceanic basins. • Agglutinated foraminifera non-selectively incorporated microplastics into tests. • Microplastics were mostly incorporated into larger foraminifera. • Microplastics were higher post-plastic production. • Microplastics were higher closer to the Mississippi River. • Microplastics were higher in deeper waters. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are widely found in the ocean and cause a serious risk to marine organisms. However, fewer studies have been conducted on benthic organisms. This study conducted a case study on the pollution characteristics of MPs on 16 marine benthic organisms in Haizhou Bay, and analyzed the effects of habitat, trophic level, and feeding mode on the MPs pollution characters. The results showed that MPs were detected in all 16 organisms with an average abundance of 8.84 ± 9.14 items/individual, which is in the middle-high level in the international scale. Among the detected MPs, the main material was cellophane. This study showed that benthic organisms can be used as indicator organisms for MPs pollution. MPs in organisms can be affected by their habitat, trophic level, and feeding mode. Comprehensive analysis of MPs in benthic organisms will contribute to fully understand the characterization and source resolution of MPs pollution. [Display omitted] • Widespread presence of MPs in benthic organisms in Haizhou Bay. • Habitat, feeding mode, and trophic level all affect the abundance of MPs in benthic organisms. • Benthic organisms can be used as indicator organisms for MPs pollution. [ABSTRACT FROM AUTHOR]

This study aimed to examine the benthic structure of Guanabara Bay's (GB) rocky shores through Functional Diversity (FD) perspective. Over a five-year period, benthic communities were periodically examined using photographic samples from the meso-littoral zone. FD were analysed using the Rao Index of marine macroalgae and benthic invertebrates' functional groups (FGs) and their relationship was investigated through null models, considering temporal, geographical, and environmental variations. The entrance site exhibited exclusive FGs and overlap niches more than expected by chance, while the inner site had a higher frequency of Bacterial Biofilm and predominance of competitive exclusion. Orthophosphate and nitrate showed significant correlations with FGs inside the bay, whereas average irradiance and rainfall were at the entrance. A functional gradient was registered, with higher Rao's Index values at the entrance compared to the inner site, probably due to increased anthropogenic disturbance and abundance of FGs with opportunistic life strategies inside GB. [Display omitted] • Rao Index efficiently assessed Guanabara Bay's rocky shores' functional structure. • Functional gradient was recorded at Guanabara Bay using benthic functional groups. • Functional groups had niche overlap and competitive exclusion in different sites. • Abiotic factors were differently correlated with functional groups in the sites. • Results emphasized the impact of anthropogenic disturbance on the bay's dynamic. [ABSTRACT FROM AUTHOR]

Antifouling paint particles (APPs) of between 500 μm and >2 mm in diameter have been identified in silty, intertidal estuarine sediments through a combination of microscopy and x-ray fluorescence spectrometry. APPs were heterogeneously distributed, with maximal concentrations of 430 particles L−1 (0.2 g L−1) near to a facility where boats are regularly maintained and 400 particles L−1 (4.2 g L−1) at a location where old boats had been abandoned, with the majority of particles encountered in the finest size fraction retrieved. APPs contained variable concentrations of Cu, Zn, Sn and Pb, with respective maxima of 562,000, 269,000, 9,970 and 126,000 mg kg−1. These characteristics are attributed to a multitude of contemporary and historic sources of an assortment of formulations and result in significant but heterogeneous metal contamination of local sediments. APPs were also identified in the guts of the deposit-feeding ragworm, Hediste diversicolor , that inhabited sediments impacted by abandoned boats or boating activities. The tissue of H. diversicolor was particularly enriched in Cu where ingested APPs were observed, with a significant correlation between dry weight Cu concentrations in the two media (r = 0.734) presumably reflecting the inability of the animal to regulate this metal. While the toxicity of APPs requires further investigation, there is clearly a need for stricter regulations on antifouling wastes in boatyards and marinas and a requirement to better manage abandoned boats. Image 1 • Antifouling paint particles (APPs) are a source of metals to the marine environment. • APPs were abundant in estuarine sediment impacted by boating activities. • APPs were identified in the guts of the deposit-feeder, Hediste diversicolor. • APPs result in elevated metal concentrations in sediment and H. diversicolor. Antifouling paint particles in contaminated estuarine sediments can be ingested by Hediste diversicolor and result in the bioaccumulation of copper. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are recognized as an increasing threat to the marine environment, but little is known about their effects on benthic organisms, including sea urchins, when ingested. For this purpose, wild sea urchins (P. lividus) and seafloor sediment samples were investigated across three coastal areas of Zakynthos Island (Ionian Sea), each exposed to different anthropogenic pressures, revealing a consistent pattern in MP abundance, shape, and color. Biomarkers related to oxidative stress, neurotoxicity, and genotoxicity showed no significant effects of MP ingestion in the sea urchins, except for a positive correlation between GST activity and ingested MPs, suggesting a possible activation of their detoxification system in response to MP ingestion. While MP concentrations in sea urchins and sediments were within the low range reported in the global literature, it remains crucial to conduct further investigations in areas with MP pollution approaching predicted levels to fully comprehend the potential effects of MP pollution on marine organisms. [Display omitted] • Low microplastic abundance in sediments and sea urchins in Zakynthos Island • Blue fibers dominate in both sediments and sea urchins. • Microplastic ingestion did not exhibit significant effect on sea urchins. • Positive correlation between GST activity and ingested MPs • FTIR analysis revealed majorly PP, PE, PVA in sediments and PP in sea urchins. [ABSTRACT FROM AUTHOR]

Direct and indirect effects on ecological processes caused by natural and anthropogenic disturbances may alter the composition and relative abundance of marine benthic communities. Trampling is a source of impact that can lead to the removal of individuals, breakage or damage of structural components and alterations of physiological performance of sessile organisms, possibly affecting the population dynamics and indirectly promoting structural changes in the entire community. To better support management strategies for coastal environments and to evaluate the anthropogenic impacts on a seaweed bed dominated by species of the genus Sargassum inhabiting the subtidal rocky shores in southeastern Brazil, we used an experimental approach to assess the physiological responses of this seaweed to trampling. We applied different intensities of trampling expected during summer vacation and throughout different periods of the year and quantified the fluorescence and pigment concentration of Sargassum beds . Changes caused by trampling are reflected in the health status of Sargassum , showing a decrease in chlorophyll a fluorescence and concentration of photosynthetic pigments depending on the site where this kind of impact occurs. [ABSTRACT FROM AUTHOR]

Single-use plastics and food packaging are the most common items polluting the environment, commonly identified in surveys and litter monitoring campaigns. There are pushes to ban these products from production and use in different regions, and to replace them with other materials viewed as "safer" or "more sustainable". Here, we address the potential environmental impacts of take-away cups and lids used for hot and cold beverages, consisting of plastic or paper. We produced leachates from plastic cups (polypropylene), lids (polystyrene), and paper cups (lined with polylactic acid), under conditions representative of plastic leaching in the environment. The packaging items were placed and left to leach in sediment and freshwater for up to four weeks, and we tested the toxicity of contaminated water and sediment separately. We used the model aquatic invertebrate Chironomus riparius and assessed multiple endpoints both on larval stages and on emergence to the adult phase. We observed a significant growth inhibition with all the materials tested when the larvae were exposed in contaminated sediment. Developmental delays were also observed for all materials, both in contaminated water and sediment. We investigated teratogenic effects via the analysis of mouthpart deformities in chironomid larvae, and observed significant effects on larvae exposed to polystyrene lid leachates (in sediment). Finally, a significant delay in time to emergence was observed for females exposed to paper cups leachates (in sediment). Overall, our results indicate that all the tested food packaging materials can have adverse effects on chironomids. These effects can be observed from one week of material leaching in environmental conditions, and tend to increase with increasing leaching time. Moreover, more effects were observed in contaminated sediment, indicating that benthic organisms might be especially at risk. This study highlights the risk posed by take-away packaging and their associated chemicals, once discarded into the environment. [Display omitted] • Leachates impacted growth, development, and emergence of chironomid larvae. • Adverse effects were observed for all the tested takeaway packaging materials. • Effects were observed after 7 days of exposure. • Stronger effects were observed in contaminated sediment, compared to water. • Effects increased with increasing leaching time. [ABSTRACT FROM AUTHOR]

Antarctica is no longer pristine due to the confirmed presence of anthropogenic contaminants like Persistent Organic Pollutants (POPs). Benthic organisms are poorly represented in contamination studies in Antarctica although they are known to bioaccumulate contaminants. Sponges (Phylum Porifera) are dominant members in Antarctic benthos, both in terms of abundance and biomass, and are an important feeding source for other organisms, playing key functional roles in benthic communities. To the best of our knowledge, legacy chlorinated POPs such as polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and dichlorodiphenyltrichloroethane (DDT) and their metabolites have never been investigated in this Phylum in Antarctica. The aim of this work was to evaluate the bioaccumulation of PCBs, HCB, o,p'- and p,p'- DDT and their DDE and DDD isomers in 35 sponge samples, belonging to 17 different species, collected along the coast of Terra Nova Bay (Adèlie Cove and Tethys Bay, Ross Sea), and at Whalers Bay (Deception Island, South Shetland Islands) in Antarctica. Lipid content showed a significant correlation with the three pollutant classes. The overall observed pattern in the three study sites was ΣPCBs>ΣDDTs>HCB and it was found in almost every species. The ΣPCBs, ΣDDTs, and HCB ranged from 54.2 to 133.7 ng/g lipid weight (lw), from 17.5 to 38.6 ng/g lw and from 4.8 to 8.5 ng/g lw, respectively. Sponges showed contamination levels comparable to other Antarctic benthic organisms from previous studies. The comparison among sponges of the same species from different sites showed diverse patterns for PCBs only in one out of four cases. The concentration of POPs did not vary significantly among the three sites. The predominance of lower chlorinated organochlorines in the samples suggested that long-range atmospheric transportation (LRAT) could be the major driver of contamination as molecules with a high long range transport potential (e.g. low chlorinated PCBs, HCB) prevails on heavier ones. [Display omitted] • First data about legacy chlorinated POPs in Antarctic sponges are reported. • Antarctic sponges are suitable organisms for legacy POPs contamination studies. • Sponges showed levels of contamination comparable to other benthic organisms. • DDTs and HCB concentrations in sponges: South Shetland Island > Ross Sea. [ABSTRACT FROM AUTHOR]

The present work assess the bioconcentration kinetics of atenolol (ATN) and carbamazepine (CBZ) in common marine organisms including Holothuria tubulosa, Anemonia sulcata and Actinia equina under controlled laboratory conditions. CBZ exhibited higher uptake and excretion rates resulting higher bioconcentration factor (BCF) (41–537 L/kg for CBZ vs 7–50 L/kg for ATN) although both are below the limits established by the European Union (EU). The measured BCF using kinetic data showed some differences with those predicted using the concentrations measured at the steady-state, probably explained because the steady state was not ready reached. The animal-specific BCF followed the order of Holothuria tubulosa > Actinia equina > Anemonia sulcata for ATN while was the opposite for CBZ. The study highlighted between-tissues differences in the digestive tract and the body wall of the Holothuria tubulosa. The work presented is the first to model bioconcentration of ATN and CBZ in holothurian and anemone animal models. [Display omitted] • Bioconcentration of ATN and CBZ in sea cucumber and anemone were investigated. • The tissue distribution of in H. tubulosa was influenced by the physico-chemical properties of compounds. • CBZ exhibited the highest first-order uptake (k 1) and elimination rate (k 2) constants. • ATN and CBZ could be classified as non bioaccumulative in tested animals. • Differences between predicted and calculated BCF values are found. [ABSTRACT FROM AUTHOR]

Environmental monitoring typically assumes samples and sampling activities to be representative of the population being studied. Given a limited budget, an appropriate sampling strategy is essential to support detecting temporal trends of contaminants. In the present study, based on real chemical analysis data on polybrominated diphenyl ethers in snails collected from five subsites in Tianmu Lake, computer simulation is performed to evaluate three sampling strategies by the estimation of required sample size, to reach a detection of an annual change of 5% with a statistical power of 80% and 90% with a significant level of 5%. The results showed that sampling from an arbitrarily selected sampling spot is the worst strategy, requiring much more individual analyses to achieve the above mentioned criteria compared with the other two approaches. A fixed sampling site requires the lowest sample size but may not be representative for the intended study object e.g. a lake and is also sensitive to changes of that particular sampling site. In contrast, sampling at multiple sites along the shore each year, and using pooled samples when the cost to collect and prepare individual specimens are much lower than the cost for chemical analysis, would be the most robust and cost efficient strategy in the long run. Using statistical power as criterion, the results demonstrated quantitatively the consequences of various sampling strategies, and could guide users with respect of required sample sizes depending on sampling design for long term monitoring programs. [ABSTRACT FROM AUTHOR]

To explore the ecological risks of trace metals in sediments and their relationship with benthic organisms, 12 trace metals were analyzed and the macrobenthos were identified in the sediments collected from the south coast of Zhejiang province which belongs to the East China Sea. Spatially, the concentrations of most trace metals were high in the estuary, except for Ba and Sr. There was no obvious enrichment for trace metals, except that the concentration of Cd slightly exceeded the coastal background. The ecological risks calculated by the concentrations of Cr, Cd, Cu, Zn, Pb, and Ni in sediments showed that the methods based on sediment quality guidelines could judge the ecological risk more intuitively than the methods based on background value (PN, PLI, RI). The significant correlations between ecological risks and benthos density and biomass revealed the negative impact of trace metals at high concentrations on macrobenthic survival in sediments. [Display omitted] • Trace metals were correlated with benthos by Ecological risk assessments. • The increasing ecological risk will reduce benthic biodensity and biomass. • Methods based on background value and SQG were used to evaluate the ecological risk. • Mostly trace metals had higher concentrations in estuary than in other regions. [ABSTRACT FROM AUTHOR]

The biological effects of activated carbon (AC) amendments in sediments were studied with the midge Chironomus riparius . The effects on larvae growth were studied using three different AC particles sizes (PAC: 90% <63 μm, MAC: ø 63–200 μm and GAC: ø 420–1700 μm). The long- term effects of MAC were studied in an emergence experiment over two generations (P, F1), together with larvae growth experiment over three generations (P, F1, F2). Retarded growth and development of the larvae were observed in the two smallest particle sizes (PAC and MAC), as well as morphological changes in the gut wall microvilli layer studied from transmission electron micrographs. In addition, at high AC treatments the larvae reaching fourth instar stage were of a smaller size compared to the controls. With PAC treatment AC amendment dosages higher than 1% of sediment dry weight induced mortality. In the emergence experiment there was an indication of a delay in F1 generation emergence. Male dry weight (dw) in P generation was significantly reduced in the 2.5% MAC treatment. The effects of AC amendments were more obvious in the C. riparius larvae compared to the effects seen in emerging adults exposed to AC-amended sediment during the larval stage. [ABSTRACT FROM AUTHOR]

In the present work, we investigated the potential benthic trophic transfer of TiO 2 nanoparticles (NPs) from clamworm ( Perinereis aibuhitensis ) to juvenile turbot ( Scophthalmus maximus ) and their related distribution and toxicity. TiO 2 NPs (at 10, 50 and 100 mg/L) could be taken up by clamworms, and mainly accumulated in the lower-digestive tract. TiO 2 NPs were able to transfer from clamworms to juvenile turbots. The accumulation of TiO 2 NPs in juvenile turbots increased with increasing Ti contents in clamworms during the dietary exposure, however, no biomagnification (BMFs, 0.30–0.33) of TiO 2 NPs was observed. For both dietary and waterborne exposure, accumulation of TiO 2 NPs was higher in the gill, intestine and stomach of juvenile turbot, following by skin, liver, and muscle. During dietary exposure at Day 20, the growth of turbots was reduced, and abnormal symptoms of liver and spleen were detected. Moreover, both dietary (50 and 100 mg/L TiO 2 NPs-treated clamworms) and waterborne (100 mg/L TiO 2 NPs) exposures led to significantly lower protein and higher lipid contents, suggesting the nutrition quality reduction of turbots. The findings from this work highlighted the trophic transfer of TiO 2 NPs in marine benthic food chain, leading to the potential negative impact on marine aquaculture and food quality. [ABSTRACT FROM AUTHOR]

In situ sorbent amendments have gained attention owing to their role in contaminated sediment remediation and their cost-effectiveness. In this study, the effectiveness of two naturally occurring, low-cost calcium-rich clay minerals, natural calcium-rich sepiolite (NCSP) and natural calcium-rich attapulgite (NCAP), were investigated as potential in situ sorbent amendments for remediation of Pb and Cd using a sediment water microcosm and 15-day bioaccumulation assays. The two amendments were mixed with sediment at rates of 0%, 2.5%, 5% and 10%. The results indicate that the two amendments can effectively reduce most of the mobile fraction of metal in sediment, which in turn reduces metal uptake by benthic organisms. Additionally, the remediation efficiency increased with application dosage. Overall, sediment treated with the highest rate of 10% NCAP and NCSP led to reductions of 56.2% and 34.2%, for Cd, and 81.5% and 77.4%, for Pb, in the acid-soluble fraction. Similarly, uptake of Pb and Cd by benthic organisms was reduced by 33.5–53.3% and 20.9–37.1%, respectively. These results highlight the potential for using these naturally occurring, calcium-rich clay minerals as in situ sorbent amendments for sediment remediation. [ABSTRACT FROM AUTHOR]

Since its introduction to Asia in the 1980s, the golden apple snail, Pomacea canaliculata (Lamarck), has represented a major constraint to the profitability of rice (Oryza sativa L.) farming by damaging rice seedlings during crop establishment. This study describes a series of experiments designed to determine the effects of nitrogenous fertilisers on snail fitness. We examined the possibility of a two-phase model of snail response to nitrogen, whereby fertilisers initially increase snail mortality through toxicity, but once assimilated into the rice ecosystem, eventually favour snail reproduction and survival. In experimental arenas, fertiliser had lethal effects: Complete fertiliser (14:14:14), urea, ammonium sulphate and organic fertilisers were associated with snail mortality, generally affecting adult snails more than juvenile snails, and with greater effects when applied to saturated soil that was subsequently flooded (as opposed to direct application to flooded soil). Snail mortality was found to decline considerably when snails were added to arenas one day after fertiliser application - this occurred in arenas with soil and water, but not in arenas with water only, suggesting that soil can reduce the toxic effects of fertilisers. In a field experiment, snail numbers declined in both fertilised and non-fertilised plots at the time of crop establishment. Numbers increased in all plots after rice tillering, with significantly more recruitment in plots with high nitrogen. Although the responses were generally weak in the field experiment, they did support the two-phase model. The consequences of fertiliser applications for snail management and ecosystem health are discussed. [ABSTRACT FROM AUTHOR]

Abstract: Several studies have suggested that communities associated with artificial substrata support more non-indigenous species (NIS) than natural habitats, and may function as corridors for their expansion. Our study focused on the role of substrate type, timing and duration of submersion as determinants of fouling assemblage. We used plates made of basalt, concrete or fibreglass, to assess early, i.e., 3 months, and late, i.e., 12 months, succession in benthic communities. To assess spatial and temporal variability of the results, sampling was performed at 2 locations and the experiment was repeated in two seasons of the year. Our results showed that the timing and duration of submersion affected the number and percent cover of natives and NIS, as well as assemblage composition. Moreover, the present study showed no support for the hypothesis that marine NIS are more abundant on artificial substrata, as neither of the two artificial substrata tested supported a greater number of NIS compared to basalt (the natural substratum). Overall, fibreglass presented the most different benthic assemblage composition, supporting the fact that the extent and nature of the observed differences varied not only between natural and artificial substrata, but also according to the type of artificial habitat considered. Thus, our results are in agreement with previous studies that stated that appropriate strategies for environmental management should integrate ecological assessment in order to maintain natural patterns of distribution and abundance of organisms, scales of variability and relevant ecological processes. [Copyright &y& Elsevier]

Abstract: This study investigated phototoxicity of TiO2 nanoparticles (nano-TiO2) to a freshwater benthic amphipod (Hyalella azteca) using 48-h and 96-h bioassays. Thorough monitoring of particle interactions with exposure media (Lake Superior water, LSW) and the surface of organisms was performed using dynamic light scattering, UV/Vis spectroscopy, and Scanning Electron Microscopy. Large agglomeration and sedimentation (>77%) in LSW was observed after 0.5h. A simulated solar radiation (SSR)-favored surface attachment of nanoparticles was observed, indicating enhanced phototoxicity with the increased attachment. A 96-h median lethal concentration (LC50) of 29.9mg/L in H. azteca was calculated, with a daily 4-h UV exposure of 2.2W/m2. Phototoxicity of nano-TiO2 under SSR had a 21-fold increase as compared to that under ambient laboratory light. This phototoxicity was also dependent on UV dose, with calculated LC50s around 22.9 (95% CI, 20.5–23.3)Wh/m2 when exposed to 20mg/L nano-TiO2. Also, H. azteca exhibited negative phototaxis in the presence of shelters, indicating that other factors might play a role in environmental systems. Finally, the environmental implications of nano-TiO2 to benthic organisms were illustrated, emphasizing the importance of various environmental factors in the ultimate phototoxicity. This increased phototoxicity and its complex interactions with various environmental factors suggest further investigations are needed for future risk assessment of photoactive nanomaterials to benthic organisms. [Copyright &y& Elsevier]

Highlights: [•] Chaetopterus variopedatus is a good biomonitor for metal contamination studies. [•] Metal burden in organisms collected in the field represents steady-state concentrations. [•] Metal concentrations in a benthic system proved to be a tool to evaluate several sources of contamination. [•] Contamination in different compartments indicates different exposure routes. [ABSTRACT FROM AUTHOR]

Abstract: The Water Framework Directive (2000/60/EC) is an innovative piece of legislation aimed at protecting the quality of all continental and coastal waters in Europe through an ecological evaluation of the ecosystems. Since it is widely acknowledged that the greater the ecological realism the greater the difficulty of its definition, we describe the different uses of benthic organisms as a tool for assessing the quality of sediment in lakes. We review the responses from single species to the community. We focus on studies in the laboratory and in the field, and we also critically consider the use of predictive models for these evaluations. Our discussion of the information collected underlines the importance of the relation between sensitivity of single species and contaminants. Moreover, the recent approach in developing mechanistic models to predict the response of natural communities seems to be particularly powerful for community ecology, and we strongly recommend more effort along these lines. [Copyright &y& Elsevier]

Abstract: Coralligenous assemblages represent the unique calcareous formations of biogenic origin in the Mediterranean Sea. Despite their importance in terms of biodiversity and biomass production, community analyses remain scarce. Actual sampling of these assemblages is complicated to carry out because their depth distribution (down to −120m) necessitates complex diving logistics. We highlight a rapid, cost-effective, objective and accurate method for the sampling of coralligenous assemblages and tested its efficiency in delineating a depth gradient. We compared seven photographic methods for estimating the percentage cover of sessile organisms: visual estimates (VS) with the aid of a 25, 64 or 100 square-grid and random-point-quadrats (RQ) with 25, 64 or 100 random points or 64 stratified random points. Comparisons were made using two simulated quadrats for which percent cover values were known. RQ with 64 random points was the method that accumulated the highest number of advantages. Using this method, two field sites were sampled by divers at three depths (−50, −60 and −70m) with increasing replication (10, 20, 30 and 40 photographic quadrats). The communities deduced from the 30 and 40 photos were similar. Community analyses showed an effect of depth nested in site on the assemblages observed. With increasing depth, encrusting algae get replaced by Porifera. Dissimilarity between −50m and −60m/−70m was mainly due to Crambe tailliezi abundance. This methodology will be a useful tool for managers and administrators; it guarantees fast abundance estimation, non-destructive repeated sampling, the possibility of comparison among researchers and the permanent record of deep-sea communities. [Copyright &y& Elsevier]

Abstract: Benthic amphipods are a keystone species in food webs of marine and freshwater systems. The amphipod in the phylogroup Diporeia found in the Great Lakes has historically been a dominant member of the benthic community and is critical to the fisheries food web. This study investigates water depth, life stage, sex, production, lipid content, and gut fullness as influences and outcomes of Diporeia distribution in Lake Superior. Samples were collected at 2- to 3-week intervals from May to October 2003 from ten stations along one transect in Lake Superior near the Keweenaw Peninsula of Michigan to determine seasonal trends in abundance and condition. Diporeia comprised, on average, 52% of the benthic macroinvertebrate community. Abundance and productivity of Diporeia is greatest within the slope region (depths of 30 to 125 m) with estimated biomass and annual P/B (production/biomass) values of 0.57 and 0.73 g/m2 for this habitat. Young-of-the-year Diporeia were the most abundant life stage in the shelf in the spring while adults were most abundant in the slope and profundal regions in fall. The greatest mean percent gut fullness occurred in September and October while the least full and empty gut occurrences were observed in June and July. The slope of the length–weight relationship for Diporeia in Lake Superior is lower (less biomass per unit length) than that observed for lakes Huron, Michigan, and Ontario. The greatest lipid content was 41% DW in July at 20 m with the overall average lipid content of Diporeia from Lake Superior in 2003 at 32% with a decline observed from September to October. The description of Diporeia abundance, distribution, and life history presented here for Lake Superior, and compared with that of other Great Lakes, will be of use in support of studies of lower food web bioenergetics. [Copyright &y& Elsevier]

Due to mining activities, concentration of uranium (U) in the environment nearby former and operating sites can be higher than in other areas. The derivation of quality criteria for U in freshwater ecosystems, rivers and lakes includes the consideration of contaminated sediments and the associated risk to the benthic life. Therefore, the derivation of a quality criteria for sediment has been viewed as a logical and necessary extension of the work already done to establish water quality criteria. In order to contribute to the determination of a Quality Standard for sediment (QS sediment) according to the European recommendations, this study focuses on the acquisition of a new toxicity dataset, to enrich the few rare existing data, most often unsuitable. A basic set of organisms, including three complementary benthic organisms (Chironomus riparius , Hyalella azteca , Myriophyllum aquaticum), was chronically exposed to U spiked to a standard laboratory-formulated sediment, according to the related bioassay guidelines (ISO/FDIS16303, OECD 218/9, ISO/DIS 16191). We looked to determine when possible both NOEC and EC 10 values for each organism. For C. riparius , a NOEC (emergence rate) value was estimated at 62 mgU, kg−1, dm and the EC 10 value reached 188 mgU, kg−1, dm (CI 95% 40–885 mgU kg−1, dm). For H. azteca, a NOEC (survival rate) value of 40 mgU kg−1, dm was observed while the EC 10 value at 296 mgU kg−1, dm (CI 95% = 155–436 mgU kg−1, dm) was slightly higher than for growth at 199 mgU kg−1, dm (CI 95% = 107–291 mgU kg−1 dm). Finally, the less sensitive organism seemed to be the plant, M. aquaticum , for which we determined a NOEC value of 100 mgU kg−1, dm. Results obtained regarding the toxicity of U made it possible to suggest a preliminary QS sediment value of 4 mgU kg−1, dry mass. This value was shown conservative compared to U sediment quality criteria derived by other jurisdictions. • Toxicity of U spiked artificial sediment was assessed according to standardized bioassays for 3 benthic species. • Survival rate of H. azteca led to a preliminary Quality Standard value derivation of 4 mgU kg−1, dry mass. • The derived preliminary Quality Standard was shown conservative compared to the reported toxicity of U in natural sediments. [ABSTRACT FROM AUTHOR]

Abstract: Marine pollutants in relation to planktonic and benthic organisms were examined at two locations along Karnataka coast, one at Kulai (74°47.74′′E and 12°55.16′′N) receiving huge amount of industrial effluents from fertilizer, petroleum and chemical plants along with the sewage discharges. The other site Padubidri (74°45′′E and 13°10′′N) is located 20km away, which is a typically agricultural and fishing village having no stress of industrial discharges. Although the concentrations of dissolved oxygen (DO), nutrients and trace metals in water and sediment showed marginal differences at these two locations, the concentration of petroleum hydrocarbon (PHC) remained exceptionally high with a maximum of 1523μg/l at Kulai which is 10 times higher than that at Padubidri (144μg/l). Biomass and population of phytoplankton and zooplankton showed that the seasonal differences were more conspicuous rather than the regional changes. Macro and meiobenthic population remained high at both the locations during the two seasons. Phytoplankton species indicated that centric diatoms such as Rhizosolenia, Leptocylindricus, Chaetoceros, Thalassiosira and Coscinodiscus contributed to >90% of population in May and >70% in January at Kulai. While mixed population of centric, pennate, cyanophycean and dinoflagellates prevailed at Padubidri in January. Lower species diversity and richness accompanied with dominance of fast growing centric diatoms over pennates observed at Kulai act as an index for detection of organic pollution and nutrient enrichment. Similarly, proliferation of benthic bivalves >54% at Kulai relative to Padubidri suggests that these organisms could sustain organic and industrial pollutants. The results suggest that although Kulai receives large quantities of industrial and sewage effluents responsible for alteration of the ecosystem structure, the excellent wind-driven mixing and tidal flushing keep the waters well aerated thus reducing the severe pollution stress by dispersing the organic and other pollutants. Direct relationship of PHC with Cd and Pb as contaminants, NO3 and PO4 as oxidants of excess PHC and species diversity as promoters of phytoplankton (centric diatoms) and benthic bivalves shown by multiple regression analysis further suggest that these biological parameters could serve as indicators for detecting moderately high environmental stress at Kulai, compared to Padubidri. [Copyright &y& Elsevier]

Abstract: Coastal areas play a crucial role in the economical, social and political development of most countries; they support diverse and productive coastal ecosystems that provide valuable goods and services. Globally flooding and coastal erosion represent serious threats along many coastlines, and will become more serious as a consequence of human-induced changes and accelerated sea-level rise. Over the past century, hard coastal defence structures have become ubiquitous features of coastal landscapes as a response to these threats. The proliferation of defence works can affect over half of the shoreline in some regions and results in dramatic changes to the coastal environment. Surprisingly little attention has been paid to the ecological consequences of coastal defence. Results from the DELOS (Environmental Design of Low Crested Coastal Defence Structures, EVK3-CT-2000-00041) project indicate that the construction of coastal defence structures will affect coastal ecosystems. The consequences can be seen on a local scale, as disruption of surrounding soft-bottom environments and introduction of new artificial hard-bottom habitats, with consequent changes to the native assemblages of the areas. Proliferation of coastal defence structures can also have critical impacts on regional species diversity, removing isolating barriers, favouring the spread of non-native species and increasing habitat heterogeneity. Knowledge of the environmental context in which coastal defence structures are placed is fundamental to an effective management of these structures as, while there are some general consequences of such construction, many effects are site specific. Advice is provided to meet specific management goals, which include mitigating specific impacts on the environment, such as minimising changes to surrounding sediments, spread of exotic species or growth of nuisance species, and/or enhancing specific natural resources, for example enhancing fish recruitment or promoting diverse assemblages for eco-tourism. The DELOS project points out that the downstream effects of defence structures on coastal processes and regional-scale impacts on biodiversity necessitate planning and management at a regional (large coastline) scale. To effectively understand and manage coastal defences, environmental management goals must be clearly stated and incorporated into the planning, construction, and monitoring stages. [Copyright &y& Elsevier]

Sediment is an important reservoir for perfluorooctane sulfonate (PFOS) in the environment, which likely poses adverse effects to benthos. In this study, the impacts of bioturbation of three benthic organisms, i.e. Chironomus kiiensis, Hyalella azteca and Limnodrilus hoffmeisteri , on the release of PFOS from sediment were investigated, and the toxic effects of PFOS to C. kiiensis were explored in the presence of one or two of the other benthic organisms. Among the three organisms, C. kiiensis displayed the weakest effect on the distribution of PFOS between sediment and water (P ＞ 0.05). The bioturbation of H. azteca and L. hoffmeisteri distinctly facilitated the suspension of sediment, leading to the enhanced amount of suspended particulate matter (SPM) and the flux of PFOS from sediment to SPM. Consequently, the concentrations of PFOS in the overlying water and pore water decreased significantly. Moreover, both H. azteca and L. hoffmeisteri affected the survival of C. kiiensis , and its mortality increased from 2.8% to 100% and 41.7% respectively. This study provides insights into the influences of bioturbation on the bioavailability of PFOS in sediments, and is helpful for accurately assessing the transport, toxicity and potential risks of PFOS in sediments. [Display omitted] • Bioturbation facilitated the release of PFOS from sediment. • Bioturbation increased the amount of suspended particulate matters in overlying water. • H. azteca and L. hoffmeisteri exhibited stronger bioturbation on sediment than C. kiiensis. • Presence of H. azteca and L. hoffmeisteri increased the mortality of C. kiiensis. [ABSTRACT FROM AUTHOR]

Microplastics are widespread in the aquatic environment and thus available for many organisms at different trophic levels. Many scientific papers focus their attention on the study of the effects of microplastics on different species at individual level. Here we performed a global scale meta-analysis focusing our work on the study of the effect of microplastics on the functional traits of aquatic benthic organisms. Overall, microplastics showed a moderate negative effect on the examined functional traits of benthic organisms. Our results show that some crucial functional traits, such as those linked to behaviour and feeding, appear to be unaffected by microplastics. In contrast, traits related to the capacity of organisms to assimilate energy are affected. Moreover, traits with possible effects at population level appear to be negatively affected by microplastics. We discuss how the direct impact of organismal performance may have indirect repercussions at higher levels in the ecological hierarchy and represent a risk for the stability and functioning of the ecosystem. [Display omitted] • We collated and synthetised scientific evidence of microplastics effects on benthos. • The meta-analysis focused on functional traits of benthic species of aquatic realms. • Microplastics showed a moderate negative effect on the examined functional traits. • Quantitative synthesis represents a robust, salient, integrated scientific baseline. • Results can inform scientists, stakeholders addressing the decision-making process. Our quantitative synthesis on the effects of microplastics on functional traits of benthic species inhabiting aquatic habitats represents a potential step forward from the existing literature focused on plastics occurrence monitoring only. [ABSTRACT FROM AUTHOR]

• Abyssal Pacific sediments were characterized both geochemically and ecologically. • Carbon fluxes affected abundance and biomass of large organisms most significantly. • Large organisms had profound differences in abundances under different POC fluxes. • Vertical distributions of labile organic matter coincided with organism distributions. • Oligotrophic ecosystems may have more trophic levels than eutrophic ecosystems. The abyssal plain covers more than half the Earth's surface. The main food source to abyssal ecosystems is phytodetritus, which originates from phytoplankton in the surface ocean, and thus its variability to the seafloor is a major driver of abyssal ecosystem biomass and functioning. In this study, we conducted a comparative survey on organic matter (OM) quality and quantity in abyssal plain sediments and examined the distributions of megafauna, macrofauna, meiofauna, prokaryotes, and viruses in eutrophic (39°N), oligotrophic (1°N), and ultra-oligotrophic (12°N) areas of the western Pacific. We also analyzed stable carbon and nitrogen isotopic compositions of organisms at 39°N and 1°N to assess differences in benthic abyssal food-web structures with contrasting trophic states. Sediments collected at 39°N presented highest concentrations of total organic carbon (TOC) and labile OM, and high diffusive oxygen uptake rates. By contrast, the lowest values were found at 12°N. Vertical distributions of sediment macrofauna, meiofauna, and prokaryotes matched with labile OM profiles. There were prominent differences in abundances of macro- and megafauna among stations with different OM fluxes, whereas the abundance of meiofauna and prokaryotes showed smaller differences among stations. Such differences could be explained by higher turnover rates of smaller organisms. Food-web structures of abyssal plains are likely influenced by both the type and size of primary producers in surface ocean. Our results underscore the crucial importance of OM fluxes and their compositions to the abundances and vertical profiles of labile OM and benthic biota in abyssal ecosystems. [ABSTRACT FROM AUTHOR]

For the image of sinking water bottles: Plastic Bottles on sea floor in Malta. Photo David Jones • Interactive effects of PET microplastics on the sea urchin were investigated. • PET microplastics were ingested and efficiently egested by sea urchins. • PET microplastics did not induce histological and biochemical effects. • Slight modification of PET macromolecular chains due to sea urchin ingestion was noted. The information concerning the toxicity of sinking microplastics (MPs) on benthic marine animals, particularly benthic grazers, is still scant. No study focused on biological weathering of sinked MPs operated by benthic organisms. This study aims at investigating the ingestion and the effects induced by 7-days dietary exposure to environmentally relevant amount (8, 80 and 800 particles/g of food) of irregular shaped and sized (diameter 12.6−1,065 μm; mean diameter 316 ± 12 μm) polyethylene terephthalate microplastics (PET-MPs) on a common marine benthic grazer, the sea urchin Paracentrotus lividus. Adverse effects were investigated on digestive tract at biochemical (oxidative stress biomarkers) and tissue level (histopathological analyses). Potential alteration of MP structure/surface and PET macromolecules due to the ingestion of PET-MPs within the sea urchin digestive tract were investigated. Results showed that PET-MPs were efficiently egested by sea urchins without producing histological alterations on digestive tract tissues, only inducing a slight modulation of oxidative status. Sea urchin grazing activity and the related transit of PET-MPs within animal digestive tract slightly affected MP structure and PET composition. These findings suggest that PET-MPs might represent an hazard for benthic grazer organisms, which can partially contribute to the degradation of PET in marine ecosystems. [ABSTRACT FROM AUTHOR]

Sea urchins serve as an essential niche for benthic ecosystems and are valuable seafood for humans. However, little is known about the microplastics (MPs) accumulation in sea urchins. Here, we investigated the abundances and characteristics of MPs in specific tissues of wild sea urchins for 12 sites across 2, 900 km of coastlines in northern China. Sea urchins from all sites were detected to have MPs, with a total detection rate of 89.52%. The MPs abundance in sea urchins from all sites ranged from 2.20 ± 1.50 to 10.04 ± 8.46 items/individual or 0.16 ± 0.09 to 2.25 ± 1.68 items/g wet weight. The samples from Dalian were found to have the highest value by individual, and samples from Lianyungang had the highest value by gram. Furthermore, MPs were found in different tissues of sea urchins, i.e., gut, coelomic fluid and gonads. The highest abundance of MPs was found in the gut of sea urchins, followed by coelomic fluid and gonads. The size of MPs ranged from 27 to 4742 μm, and the mean size found in gut was bigger than coelomic fluid and gonads. More interestingly, the MPs abundance increased with the decrease of anus size, shell diameter and gonad index (the wet weight ratio of gonad to total soft tissues). The MPs were dominated by fiber in shape, blue-green in colour and cellophane in composition. The high MPs abundance in sea urchins indicates the potential risks to human as they are consumed in many parts of the world, particularly in Asia and Europe. Unlabelled Image • A very high detection rate of MPs was found in wild sea urchins in northern China • Apart from gut, coelomic fluid and gonads could also accumulate MPs. • The mean size of MPs in gut was bigger than coelomic fluid and gonads. • MPs abundance increased with the decrease of anus size and shell diameter. • MPs abundance was negatively related to gonad index. [ABSTRACT FROM AUTHOR]

Microplastics are ubiquitous in marine environments. Sediments and marine organisms are recognized as the carriers and final destinations of microplastics. However, research on the concentration and abundance of microplastics in deep-sea sediments and organisms is limited. In this study, samples of sediments and organisms were collected from deep-sea locations of the western Pacific Ocean, with the depth ranging from 4601 m to 5732 m. Microplastics were extracted from the samples and analyzed by micro-Fourier-transform infrared spectroscopy. The average abundance of microplastics in the sediments was 240 items per kg dry weight of sediment. The microplastics were predominantly fibrous in shape (52.5%), blue in color (45.0%), and less than 1 mm in size (90.0%). The most commonly detected polymers were poly(propylene-ethylene) copolymer (40.0%) and polyethylene terephthalate (27.5%). The concentrations of polychlorinated biphenyls (PCBs), which are representatives of persistent organic pollutants, in the pore water of sediment samples were also investigated. A significant correlation between the distribution of microplastics and the PCB concentrations in sediments was found (P = 0.016). Microplastics were also detected in deep-sea organisms (i.e., Crinoidea, Pheronematidae, Ophiuroidea, and Gammaridea) in the sampling region, with an abundance of 0–3 items per individual biological sample. This assessment of microplastics in deep-sea sediments and benthic organisms of the western Pacific Ocean confirms that microplastic pollution exists in the deep-sea ecosystems of this region. Image 1 • Microplastics in western Pacific deep-sea sediments and organisms were quantified. • Microplastics found were classified by shape, color, and size. • PP-PE and PET were the predominant types of polymers. • PCB concentration in sediment pore water was correlated to microplastic abundance. The microplastic pollution in deep-sea sediments and organisms of the western Pacific Ocean were investigated. [ABSTRACT FROM AUTHOR]

Antifouling paint particles (APPs) are residues generated primarily during maintenance of vessels and marine structures, and usually occur in boat maintenance areas that are adjacent to aquatic environments, such as estuaries. APPs end up in sediment layers after their release into aquatic systems and represent a threat to benthic invertebrates, which have different habitat and feeding modes. Thus, the aim of the present study was to evaluate the toxicity of APPs-spiked sediment to the benthic microcrustaceans Monokalliapseudes schubarti (a tanaid) and Hyalella azteca (an amphipod), testing whole sediment and elutriate solutions under estuarine conditions. Whole sediment spiked with APPs was more toxic to these organisms than the elutriate solution. This toxicity was attributed to the high concentrations of Cu and Zn metals quantified in the APPs. During the whole sediment test, M. schubarti was more sensitive than H. azteca. M. schubarti is an infauna organism, and its interaction with sediments (e.g. by ingestion of sediment particles) makes it more susceptible to compounds released from APPs than H. azteca , which tends to interact with these compounds at the sediment-water interface. In addition, in tests with sediment elutriate and without sediment, M. schubarti was not affected, while elutriate with 1.50% APPs showed to be significantly toxic to H. azteca. Moreover, these results indicate that APPs act as continuous and localized sources of metals to benthic organisms, highlighting the importance of better APP management and disposal practices in boat maintenance areas to avoid local aquatic contamination. Image 1 • Antifouling paint particles (APP) act as a source of metals for sediments. • APP when in sediments are toxic to benthic organisms. • Organisms' habitat and feeding mode influence APP toxicity. • Benthic fauna inhabitant of boat maintenance zones are under threat of APP contamination. [ABSTRACT FROM AUTHOR]

Sediment is a major sink for 8:2 polyfluoroalkyl phosphate diester (8:2 diPAP) in the environment. In the present study, three representative benthic organisms, including carp (Cyrinus carpio), loach (Misgurnus anguillicaudatus) and worm (Limnodrilus hoffmeisteri), were exposed to 8:2 diPAP spiked sediment at 300 ng g−1. 8:2 diPAP in the sediment was bioavailable to carp, loach and worm even though the biota-sediment accumulation factors (BSAFs) (0.137, 0.0273, 0.413 g g−1, respectively) were relatively low due to its large molecular weight and high log K OW value. The worm displayed the greatest enrichment ability among the three species, implying the utility of using worm as a bio-indicator of 8:2 diPAP pollution in sediment. The biotransformation products (e.g. 8:2 FTUCA and 7:3 FTCA) were detected in all the three species, suggesting that they had the ability to transform 8:2 diPAP. Loach displayed the strongest metabolism capacity while worm displayed the weakest. Transformation of 8:2 diPAP also took place in the sediment by microorganisms. Notably, the concentration ratio of 7:3 FTCA and 8:2 FTUCA in the sediment was much lower than that in benthic organisms, suggesting that the aquatic benthic organisms and microorganisms had different transformation activities and mechanisms. Unlabelled Image • 8:2 diPAP in sediment was bioavailable to benthic organisms. • Biotransformation of 8:2 diPAP took place in carp, loach and worm. • Worm displayed the greatest bioaccumulation potential to 8:2 diPAP. • Loach displayed the greatest biotransformation capacity for 8:2 diPAP. • Benthic organisms displayed different metabolism mechanisms from sediment microorganisms. [ABSTRACT FROM AUTHOR]