Simulated coal spill causes mortality and growth inhibition in tropical marine organisms

Coal is a principal fossil fuel driving economic and social development, and increases in global coal shipments have paralleled expansion of the industry. To identify the potential harm associated with chronic marine coal contamination, three taxa abundant in tropical marine ecosystems (the coral Acropora tenuis, the reef fish Acanthochromis polyacanthus and the seagrass Halodule uninervis) were exposed to five concentrations (0–275 mg coal l−1) of suspended coal dust (<63 μm) over 28 d. Results demonstrate that chronic coal exposure can cause considerable lethal effects on corals, and reductions in seagrass and fish growth rates. Coral survivorship and seagrass growth rates were inversely related to increasing coal concentrations (≥38 mg coal l−1) and effects increased between 14 and 28 d, whereas fish growth rates were similarly depressed at all coal concentrations tested. This investigation provides novel insights into direct coal impacts on key tropical taxa for application in the assessment of risks posed by increasing coal shipments in globally threatened marine ecosystems

Effects of coal contamination on early life history processes of a reef-building coral, Acropora tenuis

Successful reproduction and larval dispersal are important for the persistence ofmarine invertebrate populations, and these early life history processes can be sensitive to marine pollution. Coal is emerging as a contaminant of interest due to the proximity of ports and shipping lanes to coral reefs. To assess the potential hazard of this contaminant, gametes, newly developedembryos, larvae and juveniles of the coral Acropora tenuis were exposed to a range of coal leachate, suspended coal, and coal smothering treatments. Fertilisation was the most sensitive reproductive process tested. Embryo survivorship decreased with increasing suspended coal concentrations and exposure duration, effects on larval settlement varied between treatments, while effects on juvenile survivorship were minimal. Leachate exposures had negligible effects on fertilisation and larval settlement. These results indicate that coral recruitment could be affected by spills that produce plumes of suspended coal particles which interact with gametes and embryos soon after spawning

Microplastic contamination has limited effects on coral fertilisation and larvae

Microplastics are ubiquitous throughout the world's oceans and contaminate coral reef ecosystems. There is evidence of microplastic ingestion by corals and passive contact with coral tissues, causing adverse health effects that include energy expenditure for particle removal from the tissue surface, as well as reduced growth, tissue bleaching, and necrosis. Here, it was examined whether microplastic contamination impairs the success of gamete fertilisation, embryo development and larval settlement of the reef-building coral Acropora tenuis. Coral gametes and larvae were exposed to fifteen microplastic treatments using two types of plastic: (1) weathered polypropylene particles and (2) spherical polyethylene microbeads. The treatments ranged from five to 50 polypropylene pieces L-1 and 25 to 200 microbeads L-1. Fertilisation was only negatively affected by the largest weathered microplastics (2 mm2), but the effects were not dose dependent. Embryo development and larval settlement were not significantly impacted by either microplastic type. The study shows that moderate-high levels of marine microplastic contamination, specifically particles <2 mm2, will not substantially interfere with the success of critical early life coral processes

Ingestion of microplastic debris by green sea turtles (Chelonia mydas) in the Great Barrier Reef: validation of a sequential extraction protocol

Ocean contamination by plastics is a global issue. Although ingestion of plastic debris by sea turtles has been widely documented, contamination by microplastics ( 100 μm. Two macroplastics and seven microplastics (two plastic paint chips and five synthetic fabric particles) were isolated from subsamples of two green turtles. Our results highlight the need for more research towards understanding the impact of microplastics on these threatened marine reptiles

Environmental drivers of variation in bleaching severity of Acropora species during an extreme thermal anomaly

High sea surface temperatures caused global coral bleaching during 2015–2016. During this thermal stress event, we quantified within- and among-species variability in bleaching severity for critical habitat-forming Acropora corals. The objective of this study was to understand the drivers of spatial and species-specific variation in the bleaching susceptibility of these corals, and to evaluate whether bleaching susceptibility under extreme thermal stress was consistent with that observed during less severe bleaching events. We surveyed and mapped Acropora corals at 10 sites (N = 596) around the Lizard Island group on the northern Great Barrier Reef. For each colony, bleaching severity was quantified using a new image analysis technique, and we assessed whether small-scale environmental variables (depth, microhabitat, competition intensity) and species traits (colony morphology, colony size, known symbiont clade association) explained variation in bleaching. Results showed that during severe thermal stress, bleaching of branching corals was linked to microhabitat features, and was more severe at reef edge compared with lagoonal sites. Bleaching severity worsened over a very short time-frame (∼1 week), but did not differ systematically with water depth, competition intensity, or colony size. At our study location, within- and among-species variation in bleaching severity was relatively low compared to the level of variation reported in the literature. More broadly, our results indicate that variability in bleaching susceptibility during extreme thermal stress is not consistent with that observed during previous bleaching events that have ranged in severity among globally dispersed sites, with fewer species escaping bleaching during severe thermal stress. In addition, shaded microhabitats can provide a refuge from bleaching which provides further evidence of the importance of topographic complexity for maintaining the biodiversity and ecosystem functioning of coral reefs

Validation of an optimised protocol for quantification of microplastics in heterogenous samples: A case study using green turtle chyme

Quantifying the extent of microplastic (100 μm: polyethylene, high-density polyethylene, (aminoethyl) polystyrene, polypropylene, and polyvinyl chloride, with 100% efficiency. This validated protocol will enable researchers worldwide to quantify microplastic contamination in turtles in a reliable and comparable way. • Optimization of microplastic extraction from multifarious tissues by applying established methods in a sequential manner. • Effective for heterogenous samples comprising organic and inorganic material. Method name: Sequential protocol for extracting microplastics from heterogenous sample matrices, Keywords: Plastic ingestion, Marine debris, Plastic contamination, Extraction technique, Chemical digestion, Density separation, Fourier transform-infrared spectroscop

Coastal urbanization influences human pathogens and microdebris contamination in seafood

Seafood is one of the leading imported products implicated in foodborne outbreaks worldwide. Coastal marine environments are being increasingly subjected to reduced water quality from urbanization and leading to contamination of important fishery species. Given the importance of seafood exchanged as a global protein source, it is imperative to maintain seafood safety worldwide. To illustrate the potential health risks associated with urbanization in a coastal environment, we use next-generation high-throughput amplicon sequencing of the 16S ribosomal RNA gene combined with infrared spectroscopy to characterize and quantify a vast range of potential human bacterial pathogens and microdebris contaminants in seawater, sediment and an important oyster fishery along the Mergui Archipelago in Myanmar. Through the quantification of >1.25 million high-quality bacterial operational taxonomic unit (OTU) reads, we detected 5459 potential human bacterial pathogens belonging to 87 species that are commonly associated with gut microbiota and an indication of terrestrial runoff of human and agricultural waste. Oyster tissues contained 51% of all sequenced bacterial pathogens that are considered to be both detrimental and of emerging concern to human health. Using infrared spectroscopy, we examined a total of 1225 individual microdebris particles, from which we detected 78 different types of contaminant materials. The predominant microdebris contaminants recovered from oyster tissues included polymers (48%), followed by non-native minerals (20%), oils (14%) and milk supplement powders (14%). Emerging technologies provide novel insights into the impacts of coastal development on food security and risks to human and environmental health

Sources, presence and potential effects of contaminants of emerging concern in the marine environments of the Great Barrier Reef and Torres Strait, Australia

Current policy and management for marine water quality in the Great Barrier Reef (GBR) in north-eastern Australia primarily focusses on sediment, nutrients and pesticides derived from diffuse source pollution related to agricultural land uses. In addition, contaminants of emerging concern (CECs) are known to be present in the marine environments of the GBR and the adjacent Torres Strait (TS). Current and projected agricultural, urban and industrial developments are likely to increase the sources and diversity of CECs being released into these marine ecosystems. In this review, we evaluate the sources, presence and potential effects of six different categories of CECs known to be present, or likely to be present, in the GBR and TS marine ecosystems. Specifically, we summarize available monitoring, source and effect information for antifouling paints; coal dust and particles; heavy/trace metals and metalloids; marine debris and microplastics; pharmaceuticals and personal care products (PPCPs); and petroleum hydrocarbons. Our study highlights the lack of (available) monitoring data for most of these CECs, and recommends: (i) the inclusion of all relevant environmental data into integrated databases for building marine baselines for the GBR and TS regions, and (ii) the implementation of local, targeted monitoring programs informed by predictive methods for risk prioritization. Further, our spatial representation of the known and likely sources of these CECs will contribute to future ecological risk assessments of CECs to the GBR and TS marine environments, including risks relative to those identified for sediment, nutrients and pesticides