In the present study, we analyzed the influence of untreated sewage exposure on carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopic composition and several biochemical responses in the barnacle Balanus glandula. The main objective was to evaluate whether changes in stable isotopes signature do reflect biochemical sub-lethal effects in a sewage influence gradient. Stable isotopes analysis showed differences in isotope signatures between close sewage influence and distant sites, being δ¹³C signatures stronger than that of δ¹⁵N. Regarding biochemical effects, although organisms close to the effluent would be clearly exposed to contaminants (increased GST activity) the oxidative stress would not be too evident (peroxidases and ACAP not affected). The most affected physiological aspect was the digestive one, reflected in increased alkaline proteases and lipases activities. A clear relation between δ¹⁵N and GST activity was found, showing to δ¹⁵N as an indicator of potential exposure to chemical contaminants.

The purpose of this study was to quantify phosphorus bioavailability and various forms of this element in surface sediments of the southern Caspian Sea. To do, sediment samples were collected from different depths in autumn 2015 using a Van Veen Grab. Phosphorus forms were recognized by a sequential extraction procedure (SEDEX). Results revealed that the range of total phosphorus (TP) was between 431ppm and 594ppm with a mean value of 535.25±45.05ppm. Organic phosphorus (OP) ranged from 62 to 99ppm and contributed 14.85±2.21% of total phosphorus in average. The contents of loosely phosphorus, iron-bound phosphorus, authigenic phosphorus and detrital phosphorus varied 35–55ppm, 50–94ppm, 125–189ppm and 152–217ppm, respectively. Generally, inorganic phosphorus (IP) was between 365 and 522ppm which comprised 81.9–88.53% of total phosphorus. Findings showed levels of different phosphorus forms in a descending order: detrital P>Authigenic P>Organic P>Fe-P>Loosely P. Bioavailable phosphorus concentration was between 153ppm and 240ppm and consisted 37.21±3% of total phosphorus. Based on molar ratio of TOC/OP, organic matter obtained from the studied stations suggested a terrestrial origin.

Based on a survey conducted from June to July 2013, aragonite saturation state variation and control in the river-dominated marginal BoHai and Yellow seas were investigated. Surface water Ωarag ranged from 2.0–3.8, whereas subsurface water Ωarag was generally lower than 2.0. Temperature changes had a strong influence on Ωarag through induced CO2 solubility changes in seawater. Riverine freshwater input decreased Ωarag in the Changjiang and Yalu river estuaries, but induced higher Ωarag in the Yellow River estuary. Biological processes had opposite effects on Ωarag, whereby elevated biological production led to the highest Ωarag in the South Yellow Sea surface water, whereas net community respiration/remineralization induced low Ωarag in subsurface water. Stratification affected the level and scale of low Ωarag in subsurface water. By the year 2100, surface water with Ωarag > 2.0 will disappear except for the Yellow River estuary, and most of the subsurface water will develop substantial aragonite undersaturation.

This study presents data on the marine litter occurrence in the stomachs of fish species living in different marine habitats for the Adriatic and NE Ionian Sea macro-region. “Macro-litter” was examined in 614 specimens belonging to 11 species, while micro-litter in 230 specimens belonging to 7 species. The study highlights for the first time the presence of litter in the stomachs of the fish species Citharus linguatula. The occurrence of “macro-litter” in the guts of fish was <3% in both the NE Ionian and N Adriatic but reached 26% in the S Adriatic Sea. Micro-litter occurrence was 40 for the NE Ionian and increased to 87% in the N Adriatic (Slovenian Sea). The ingested “macro” and micro-litter differed among the areas. The marine habitat was found to affect the “macro”-litter ingestion but not the micro-litter.

Conventional methods for determination of polycyclic aromatic compounds (PACs) in sediments usually require large sample sizes (grams) and solvent volumes (at least 100 mL) through the employment of Soxhlet extraction, which is both time (hours) and energy consuming, among other disadvantages. We developed a new analytical protocol for the determination of PACs in sediments using microextraction, which requires small sample masses (25 mg), 500 μL of acetonitrile-dichloromethane mix and sonication for 23 min, followed by GC–MS analysis. The method was validated using the certified reference material SRM 1941b – NIST organic marine sediment, as well as internal deuterated standards. Seventeen PAHs, seven nitro-PAHs and one quinone were detected and quantified. The mean concentrations were 90.4 ng g−1 for PAHs, 179.2 ng g−1 for nitro-PAHs and 822.5 ng g−1 for quinones. The proposed method showed good sensitivity, linearity, precision and accuracy for the determination of PAC in sediments samples.

Given the growing saliency of plastic marine debris, and the impact of plastics on beaches and aquatic environments in the Laurentian Great Lakes, applied research is needed to support municipal and nongovernmental campaigns to prevent debris from reaching the water's edge. This study addresses this need by examining the barriers and benefits to positive behavior for two plastic debris items in northeast Ohio's Lake Erie basin: plastic bags and plastic water bottles. An online survey is employed to gather data on the use and disposal of these plastic items and to solicit recommendations on how to positively change behavior to reduce improper disposal. Results support a ban on plastic bags and plastic water bottles, with more enthusiasm for a bag ban. Financial incentives are also seen as an effective way to influence behavior change, as are location-specific solutions focused on education and outreach.

A distinctive feature of the Deepwater Horizon (DwH) oil spill was the formation of significant quantities of marine oil snow (MOS), for which the mechanism(s) underlying its formation remain unresolved. Here, we show that Alteromonas strain TK-46(2), Pseudoalteromonas strain TK-105 and Cycloclasticus TK-8 – organisms that became enriched in sea surface oil slicks during the spill – contributed to the formation of MOS and/or dispersion of the oil. In roller-bottle incubations, Alteromonas cells and their produced EPS yielded MOS, whereas Pseudoalteromonas and Cycloclasticus did not. Interestingly, the Cycloclasticus strain was able to degrade n-alkanes concomitantly with aromatics within the complex oil mixture, which is atypical for members of this genus. Our findings, for the first time, provide direct evidence on the hydrocarbon-degrading capabilities for these bacteria enriched during the DwH spill, and that bacterial cells of certain species and their produced EPS played a direct role in MOS formation.

Natural marine snow (NMS) is defined as the “shower” of particle aggregates formed by processes that occur in the world's oceans, consisting of macroscopic aggregates of detritus, living organisms and inorganic matter. Recent studies from the Deepwater Horizon oil spill suggest that marine snow is also formed in association with oil spills and was an important factor for the transport of oil to the seabed. This review summarizes the research and literature on MS, mainly from the DWH oil spill, with a focus on the relation between the use of oil spill dispersants and the formation and fate of oil-related marine snow (ORMS). Studies are still required to determine ORMS processes at oil concentrations as relevant as possible for chemically dispersed oil.

This study provides the first quantification of plastic ingestion in the Tristram's Storm-petrel (Oceanodroma tristrami) in over 20 years. We found 100% plastic incidence in 57 chicks collected opportunistically over four breeding seasons (2007, 2010, 2011, 2012), with the mass of ingested plastic per individual ranging from 0.1 to 2.8 g (≤3.3% adult mass). While plastic occurred in every bird we examined, the proventriculus contained significantly more plastic, more fragments, and larger fragments than the gizzard. Most of the ingested plastic (97.5% by mass) consisted of fragments, ranging in length from 0.4 to 11.6 mm and ranging in surface area from 0.07 to 45.21 mm2. While fragments were ubiquitous, occurring in every proventriculus and gizzard we analyzed, Tristram's Storm-petrels also ingested foam, line and sheets. Digital analysis of 1425 ingested plastic fragments documented a wide range of colors, involving shades of white, yellow, orange, red, blue, green, and black.

In this work, we performed a comparative study on six marine sponge species collected along the French Mediterranean and Irish coasts for their TEs accumulation. Intra and inter-species variabilities were examined. Among the Mediterranean species, Cymbaxinella damicornis accumulates significantly more As and Cu than others sponge species; Chondrilla nucula more Ni and Mo and Acanthella acuta more Ag. Among Irish samples, Hymeniacidon perlevis showed higher accumulation properties for most of TEs in comparison to Halichondria panicea. Bioconcentration Factors were > 1 in all species for most of TEs. This study suggests that TEs bioaccumulation is most likely associated to differences in morphological features and/or to specific bacterial communities associated to different species. The determination of Pb isotope ratios revealed mainly natural Pb sources for Mediterranean and Kilkieran Bay's samples, and rather anthropogenic influence for Belfast samples. This study confirms that sponges represent a powerful tool for biomonitoring studies.