The effects of confounding by temporal factors remains understudied in pollution ecology. For example, there is little understanding of how disturbance history affects the development of assemblages. To begin addressing this gap in knowledge, marine biofilms were subjected to temporally-variable regimes of copper exposure and depuration. It was expected that the physical and biological structure of the biofilms would vary in response to copper regime. Biofilms were examined by inductively coupled plasma optical emission spectrometry, chlorophyll-a fluorescence and field spectrometry and it was found that (1) concentrations of copper were higher in those biofilms exposed to copper, (2) concentrations of copper remain high in biofilms after the source of copper is removed, and (3) exposure to and depuration from copper might have comparable effects on the photosynthetic microbial assemblages in biofilms. The persistence of copper in biofilms after depuration reinforces the need for consideration of temporal factors in ecology.

Organic and inorganic pollutant levels were determined for the most discarded species from trawlers operating in Great Sole and Spanish coastal fishing grounds. Results for heavy metals indicated that Cd can reach values higher than legal limits for some species and tissues, while Hg and Pb concentrations are below established values. No significant variation was noticed with fishing grounds, but both season influences in the case of Pb and interspecies variation for Hg and Cd have been detected. Valorization recommendations could be therefore established according to the levels found in the different species.

Based on a modified trait hierarchy of body-size units, the feasibility for bioassessment of water pollution using body-size distinctness of planktonic ciliates was studied in a semi-enclosed bay, northern China. An annual dataset was collected at five sampling stations within a gradient of heavy metal contaminants. Results showed that: (1) in terms of probability density, the body-size spectra of the ciliates represented significant differences among the five stations; (2) bootstrap average analysis demonstrated a spatial variation in body-size rank patterns in response to pollution stress due to heavy metals; and (3) the average body-size distinctness (Δz+) and variation in body-size distinctness (Λz+), based on the modified trait hierarchy, revealed a clear departure pattern from the expected body-size spectra in areas with pollutants. These results suggest that the body-size diversity measures based on the modified trait hierarchy of the ciliates may be used as a potential indicator of marine pollution.

The common dolphin (Delphinus delphis) is one of the most abundant species in Atlantic Iberia, representing a potentially important tool to assess the bioaccumulation of trace elements in the Iberian marine ecosystem. Nine elements (As, Cd, Cu, Hg, Mn, Ni, Pb, Se and Zn) were evaluated in 36 dolphins stranded in continental Portugal. Dolphins had increasing Hg concentrations (16.72μg·g−1 ww, liver) compared with previous studies in Atlantic Iberia, whereas Cd concentrations (2.26μg·g−1 ww, kidney) fell within reported ranges. The concentrations of some trace elements (including Cd and Hg) presented positive relationships with dolphin length, presence of parasites and gross pathologies. Common dolphins may help biomonitoring more offshore Atlantic Iberian areas in future studies, which would otherwise be difficult to assess.

We investigated distribution, sources, and potential risks of polycyclic aromatic hydrocarbons (PAHs) in the surface sediments from the largest mariculture base in the eastern part of the province of Guangdong in southern China. Total concentrations of ∑PAHs were 29.38–815.46ng/g (dry weight), with a mean of 421.48ng/g. The composition of PAHs was characterized by an abundance of low molecular weight PAHs (2–3 benzenoid ring), and Phenanthrene (PHE), Anthracene (AN) and Fluoranthene (FA) were the predominant constituents. PAHs in this area appear to have mainly originated from petroleum sources and the combustion of grass, wood, and coal. PAHs in surface sediments of Zhelin Bay had a 9% incidence of causing adverse biological effects on aquatic organisms, according to the mean effects range–median quotient.

This work developed a new method to determine concentration of Corexit EC9500A, and likely other oil dispersants, in seawater. Based on the principle that oil dispersants decrease surface tension, a linear correlation was established between the dispersant concentration and surface tension. Thus, the dispersant concentration can be determined by measuring surface tension. The method can accurately analyze Corexit EC9500A in the concentration range of 0.5–23.5mg/L. Minor changes in solution salinity (<0.3%), pH (7.9–9.0), and dissolved organic matter (<2.0mg/L as TOC) had negligible effects on the measurements. Moreover, effects of extracts from marine sediments were negligible, and thus, the method may be directly applied to seawater–sediment systems. The method accuracy was confirmed by comparing with direct TOC analysis. This simple, fast, economical method offers a convenient analytical tool for quantifying complex oil dispersants in water/seawater, which has been desired by the oil spill research community and industries.

The effect of ozonation on treatment of diesel-contaminated water was investigated on a laboratory scale. Factorial design and response surface methodology (RSM) were used to evaluate and optimize the effects of pH, ozone flow rate, and contact time on the treatment process. A Box–Behnken design was successfully applied for modeling and optimizing the removal of total petroleum hydrocarbons (TPHs). The results showed that ozonation is an efficient technique for removing diesel from aqueous solution. The determination coefficient (R2) was found to be 0.9437, indicating that the proposed model was capable of predicting the removal of TPHs by ozonation. The optimum values of experimental initial pH, degree of O3, and reaction time were 7.0, 1.5, and 35min, respectively, which could contribute to approximately 60% of TPH removal. This result is in good agreement with the predicted value of 57.28%.

Estuaries are very important ecosystems with great ecological and economic value, but usually highly impacted by anthropogenic pressure. Thus, the assessment of pollution levels in these habitats is critical in order to evaluate their environmental quality. In this work, we combined complementary metallomic and proteomic approaches with the aim to monitor the effects of environmental pollution on Scrobicularia plana clams captured in three estuarine systems from the south coast of Portugal; Arade estuary, Ria Formosa and Guadiana estuary. Multi-elemental profiling of digestive glands was carried out to evaluate the differential pollution levels in the three study areas. Then, proteomic analysis by means of two-dimensional gel electrophoresis and mass spectrometry revealed twenty-one differential proteins, which could be associated with multiple toxicological mechanisms induced in environmentally stressed organisms. Accordingly, it could be concluded that the combination of different omic approaches presents a great potential in environmental research.

Marine plastic pollution is rapidly growing and is a source of major concern. Seabirds often ingest plastic debris and are increasingly used as biological monitors of plastic pollution. However, virtually no studies have assessed plastics in seabirds in the deep subtropical North Atlantic. We investigated whether remains of white-faced storm-petrels (WFSP) present in gull pellets could be used for biomonitoring. We analysed 263 pellets and 79.0% of these contained plastic debris originating in the digestive tract of WFSP. Pellets with no bird prey did not contain plastics. Most debris were fragments (83.6%) with fewer plastic pellets (8.2%). Light-coloured plastics predominated (71.0%) and the most frequent polymer was HDPE (73.0%). Stable isotopes in toe-nails of WFSP containing many versus no plastics did not differ, indicating no individual specialisation leading to differential plastic ingestion. We suggest WFSP in pellets are highly suitable to monitor the little known pelagic subtropical Northeast Atlantic.

Microplastics are firmly recognized as a ubiquitous and growing threat to marine biota and their associated marine habitats worldwide. The evidence of the prevalence of microplastics was documented for the first time in the marine waters of Qatar's Exclusive Economic Zone (EEZ). An optimized and validated protocol was developed for the extraction of microplastics from plankton-rich seawater samples without loss of microplastic debris present and characterized using Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy. In total 30 microplastic polymers have been identified with an average concentration of 0.71particlesm−3 (range 0–3particlesm−3). Polypropylene, low density polyethylene, polyethylene, polystyrene, polyamide, polymethyl methacrylate, cellophane, and acrylonitrile butadiene styrene polymers were characterized with majority of the microplastics either granular shape, sizes ranging from 125μm to 1.82mm or fibrous with sizes from 150μm to 15.98mm. The microplastics are evident in areas where nearby anthropogenic activities, including oil-rig installations and shipping operations are present.