Trophodynamics and chiral signatures of organochlorine pesticides (OCPs), including dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), and chlordanes in a food web from Zhoushan Fishing Ground, China, were studied. Residues of OCPs in all teleost fishes were within food safety levels. Strong positive correlations were found between trophic levels (TLs) and wet weight concentrations of target chemicals, with trophic magnification factors (TMFs) from 4.17 to 9.77. Lipid contents and TLs significantly correlated, which indirectly affect the bioaccumulation processes of OCPs. The consistently racemic EF values of α-HCH, as well as invariability of the relative proportions of HCH isomers in different marine species implied that HCHs in animals originate directly from the surrounding environment. However, in vivo biotransformation and/or elimination of o,p′-DDT cannot be precluded. TMFs of the individual enantiomers further suggest that the influence of achiral biotransformation is too minor to induce enantioselective biomagnification of chiral OCPs through the studied food web.

The spatial and seasonal distribution of trace elements (TEs) (n=16) in surficial sediment were examined along the Hooghly River Estuary (~175km), India. A synchronous elevation of majority of TEs concentration (mgkg⁻¹) was encountered during monsoon with the following descending order: Al (67070); Fe (31300); Cd (5.73); Cr (71.17); Cu (29.09); Mn (658.74); Ni (35.89). An overall low and homogeneous concentration of total Hg (THg=17.85±4.98ngg⁻¹) was recorded in which methyl mercury (MeHg) shared minor fraction (8–31%) of the THg. Sediment pollution indices, viz. geo-accumulation index (Igₑₒ) and enrichment factor (EF) for Cd (Igₑₒ=1.92–3.67; EF=13.83–31.17) and Ba (Igₑₒ=0.79–5.03; EF=5.79–108.94) suggested high contamination from anthropogenic sources. From factor analysis it was inferred that TEs primarily originated from lithogenic sources. This study would provide the latest benchmark of TE pollution along with the first record of MeHg in this fluvial system which recommends reliable monitoring to safeguard geochemical health of this stressed environment.

Subsea oil well blowouts and pipeline leaks release oil and gas to the environment through vigorous jets. Predicting the breakup of the released fluids in oil droplets and gas bubbles is critical to predict the fate of petroleum compounds in the marine water column. To predict the gas bubble size in oil well blowouts and pipeline leaks, we observed and quantified the flow behavior and breakup process of gas for a wide range of orifice diameters and flow rates. Flow behavior at the orifice transitions from pulsing flow to continuous discharge as the jet crosses the sonic point. Breakup dynamics transition from laminar to turbulent at a critical value of the Weber number. Very strong pure gas jets and most gas/liquid co-flowing jets exhibit atomization breakup. Bubble sizes in the atomization regime scale with the jet-to-plume transition length scale and follow −3/5 power-law scaling for a mixture Weber number.

Research into sediment-seagrass tissue metal relationships has been undertaken in Sydney estuary due to the recognized role contamination plays in threats to seagrass health. Seagrass (Halophila ovalis) leaf tissue concentrations are elevated in Cu, Pb and Zn and contain the highest reported root Cr concentrations. Seagrass metal concentrations were significantly different between species H. ovalis and Zostera capricorni; between root and leaf tissue; and between sampling locations. Greatest tissue enrichment was for Pb, however metals were not enriched in seagrass relative to surficial sediment. Fine and total sediment metal concentrations were temporally consistent between collection years 2013/15, whereas root tissue metals changed between years and sites and leaf metal contents were temporally inconsistent. Extractable metal concentrations in fine sediment (<62.5 μm) showed moderate significant correlation with root tissue and a weak significant relationship with leaf tissue, whereas total sediment metal showed no such relationships. Management implications are provided.

This study investigated the anti-estrogenic effects of chronic exposure to a new marine pollutant, semicarbazide (SMC; 1, 10, and 100μg/L), in female Paralichthys olivaceus, as well as the associated mechanism. After 130days of exposure, plasma 17β-estradiol and testosterone concentrations, and hepatic estrogen receptors, vitellogenin, and choriogenin mRNA levels decreased significantly in SMC-exposed groups. Moreover, down-regulation of genes in the hypothalamic-pituitary-gonadal axis, including gonadotropin-releasing hormone, gonadotropic hormones and their receptors, the steroidogenic acute regulatory protein, 17α-hydroxylase, 17β-hydroxysteroid dehydrogenase, and cytochrome P450 19A, was observed after SMC exposure. Furthermore, the kisspeptin/g protein-coupled receptor 54 (kiss/gpr54) system and gamma-aminobutyric acid-ergic (GABAergic) system were also affected by SMC: SMC significantly down-regulated mRNA expression of kiss2, gpr54, and the GABA synthesis enzyme gad67. Our results demonstrated for the first time that environmentally relevant concentrations of SMC exerted anti-estrogenicity in female flounders, providing theoretical support for ecological risk assessments of SMC in marine environments.

Past climate changes provide important clues for advancement of studies on current global change biology. We have tested large-scale biogeographic patterns through four marine groups from twelve Atlantic Ocean archipelagos and searched for patterns between species richness/endemism and littoral area, age, isolation, latitude and mean annual sea-surface temperatures. Species richness is strongly correlated with littoral area. Two reinforcing effects take place during glacial episodes: i) species richness is expected to decrease (in comparison with interglacial periods) due to the local disappearance of sandy/muddy-associated species; ii) because littoral area is minimal during glacial episodes, area per se induces a decrease on species richness (by extirpation/extinction of marine species) as well as affecting speciation rates. Maximum speciation rates are expected to occur during the interglacial periods, whereas immigration rates are expected to be higher at the LGM. Finally, sea-level changes are a paramount factor influencing marine biodiversity of animals and plants living on oceanic islands.

Human-induced global change is expected to amplify the disease risk for marine biota. However, the role of disease in the rapid global decline of seagrass is largely unknown. Global change may enhance seagrass susceptibility to disease through enhanced physiological stress, while simultaneously promoting pathogen development. This review outlines the characteristics of disease-forming organisms and potential impacts of global change on three groups of known seagrass pathogens: labyrinthulids, oomycetes and Phytomyxea. We propose that hypersalinity, climate warming and eutrophication pose the greatest risk for increasing frequency of disease outbreaks in seagrasses by increasing seagrass stress and lowering seagrass resilience. In some instances, global change may also promote pathogen development. However, there is currently a paucity of information on these seagrass pathosystems. We emphasise the need to expand current research to better understand the seagrass-pathogen relationships, serving to inform predicative modelling and management of seagrass disease under future global change scenarios.

Sub-Seabed CCS is regarded as a key technology for the reduction of CO₂ emissions, but little is known about the mechanisms through which leakages from storage sites impact benthic species. In this study, the biological responses of the infaunal bivalve Limecola balthica to CO₂-induced seawater acidification (pH7.7, 7.0, and 6.3) were quantified in 56-day mesocosm experiments. Increased water acidity caused changes in behavioral and physiological traits, but even the most acidic conditions did not prove to be fatal. In response to hypercapnia, the bivalves approached the sediment surface and increased respiration rates. Lower seawater pH reduced shell weight and growth, while it simultaneously increased soft tissue weight; this places L. balthica in a somewhat unique position among marine invertebrates.

Pollution of shooting range soils by lead from bullets represents a widespread and potentially significant concern for impact on the environment. High concentrations of lead in particular are reported in bullet impact berms and shot fall zones. The other components of bullets used in shooting including antimony, copper and zinc may also be present at elevated concentrations. Antimony is a concern due to its mobility in the environment. It has been recognised that the status of contamination is important for the risk presented by shooting ranges. Lead bullets are subject to weathering in the soil, forming secondary minerals, which may be solubilised and may release lead and co-contaminants into the soil. The mobility and availability of contaminants in the soil affect their potential for spreading in the environment and for uptake and toxicity in organisms. Soil physicochemical properties affect bullet weathering and availability of contaminants in the soil. A number of strategies have been researched for management of shooting range pollution such as chemical stabilisation, phytoremediation and soil washing. This review considers the current state of knowledge and research of contamination and management of shooting ranges from recent literature (2014–2017) reflecting on new knowledge and novel management strategies for shooting range soil management. Ultimately, management of pollution in shooting range soils should seek to remove bullets from soil, reduce the weathering of bullets and reduce the mobility and bioavailability of contaminants. Adopted management practices should be based an understanding of site-specific condition, to achieve the most optimal outcome.

The present study investigates the distribution of heavy metals (Fe, Cd, Co, Cr, Cu, Ni, Zn and Pb) in the surface sediments along the Coromandel Coast of Bay of Bengal as an indicator of marine pollution. Pollution indices such as Contamination factor (CF), Enrichment factor (EF) and Geo-accumulation index (I) were performed to assess the spatial distribution and pollution status of the study area. The heavy metal concentration in the study area is closely associated with grain size and organic matter. Both geoaccumulation index and metal contamination factor indicate that the sediments are free from contamination with regards to the metals Cr and Ni, followed by uncontamination to moderate contamination of Co, Cu and Zn. However, sediments are found to be extremely polluted with respect to Cd and Pb. Factor analysis reveals that the accumulation of these heavy metals in the shelf sediments are due to anthropogenic inputs from the adjacent land area.