While introduced marine species have been arriving in Australia for centuries, it was the advent of container shipping and the discharge of ballast water into Australian ports that highlighted the problem. A summary is provided of how Australia responded to this challenge and continues to. More recently there has been an acceptance that hull fouling is also an important vector of introductions. A major problem in Australia is distinguishing introduced species from as yet undescribed native species. This is a particular problem in northern Australia where the native fauna is poorly documented. Despite the economic and environmental threats posed by introduced species, the impetus to undertake expensive comprehensive surveys has declined and attention is now focusing on targeted surveys especially of known marine pest species and molecular data to identify introductions. Ongoing research is still needed to monitor other species identified as being introduced and their potential to become pests.

Prior to Brazil's worst environmental disaster, caused by a mining dam collapse, we had carried out a study of the marine benthic macrofauna (11–51 m depth) under the influence of the Doce River. Our results showed significant diversity, in which mollusks, polychaetes, and crustaceans had the highest frequency, density, and abundance, represented by 162 families in summer and 173 in winter. Our results suggested that richness, abundance, and diversity increase with distance from the coast. Furthermore, with increasing distance from the coast and river mouth, in addition to increasing depth, there was a differentiation in composition and abundance. Multivariate analyses showed depth, carbonate, and organic matter as important factors that explain variations in composition and diversity across the continental shelf. The results could provide an invaluable baseline for measuring the effects on shallow and mesophotic communities of one of the largest tailings dam failures worldwide.

Marine litter, in particular plastic debris, poses a serious threat to marine life, human health and the economy. In order to reduce its impact, marine litter collections such as beach clean-ups are frequently conducted. This paper presents a systematic review of temporal developments, geographical distribution, quantities and waste treatment pathways of collected marine litter. Results from over 130 studies and projects highlight the worldwide increase in collection efforts. Many of these are in wealthy countries that do not primarily contribute to the problem. Over 250 thousand tonnes, have already been removed, but there is little or no information available regarding how this waste is treated or used post collection. This paper highlights the need for a whole-system quantitative assessment for the collection and waste treatment of marine litter, and identifies the challenges associated with utilising this waste in the future.

From the 1980's, Indonesian shrimp production has continuously increased through a large expansion of cultured areas and an intensification of the production. As consequences of diseases and environmental degradations linked to this development, there are currently 250,000ha of abandoned ponds in Indonesia. To implement effective procedure to undertake appropriate aquaculture ecosystem assessment and monitoring, an integrated indicator based on four criteria using very high spatial optical satellite images, has been developed to discriminate active from abandoned ponds. These criteria were: presence of water, aerator, feeding bridge and vegetation. This indicator has then been applied to the Perancak estuary, a production area in decline, to highlight the abandonment dynamic between 2001 and 2015. Two risk factors that could contribute to explain dynamics of abandonment were identified: climate conditions and pond locations within the estuary, suggesting that a spatial approach should be integrated in planning processes to operationalize pond rehabilitation.

The ingestion of microplastics and natural fibres (<5 mm) was assessed for two commercial fish species in the western Mediterranean Sea: Sardina pilchardus and Engraulis encrasicolus. Gastrointestinal tracts from 210 individuals from 14 stations were examined with 14.28–15.24% of the small pelagic fish S. pilchardus and E. encrasicolus having ingested microplastics and natural fibres. A latitudinal increase in condition index (Fulton's K) of S. pilchardus gave an indication that larger individuals with better physical condition are less likely to ingest microplastics and natural fibres. Fibres were the most frequent particle type (83%) and Fourier Transform Infrared spectroscopy (FT-IR) analysis indicated polyethylene terephthalate was the most common microplastics material (30%). Results from this study show that both microplastics and natural fibres of anthropogenic origin are common throughout the pelagic environment along the Spanish Mediterranean coast.

The global ban on the use of tributyltin (TBT) forced in September 2008 was ratified in Tunisia as late as June 2011. In this context, the present study aims to highlight the consequences of TBT contamination by monitoring 22 Tunisian sites before (2007) and after the ban (2012 and 2016) using as biomarker the occurrence of imposex in Hexaplex trunculus. From 2004 to 2016, complete recovery from imposex was reported in 11 sites. All average imposex indices calculated for each sampling year also decreased: imposex incidence from 61 to 27%, VDSI from 2 to 0.7, and RPLI from 15.7 to 1.6%. Ecological Quality Ratios (EQR) revealed that the sampling sites are in moderate to good ecological status. Overall, the present study confirms the effectiveness of the enacted legislation in reducing the impact of TBT pollution along the Tunisian coast.

There are significant differences in the aggregation mechanisms and types of aggregates that form by oil-particle interactions in marine and laboratory environments depending on the state of oil (i.e., dissolved, emulsified, floating), size and type of particles involved (i.e., colloidal, granular, organic, inorganic), oil-particle interaction mechanisms, and settling/suspension characteristics. Distinct characteristics of oil-particle aggregates that form by interaction of granular particles with floating oil separate them from the well-known oil-colloidal particle aggregates (OcPA), which are sometimes called Pickering emulsions. Unlike OcPA, which involve emulsified oil (entrained oil droplets suspended in the water column) and colloidal particles, the oil-granular particle aggregates (OgPA) involve the floating oil and granular particles. Here, to clarify the differences and similarities between the two types of aggregates (OcPA and OgPA), we present classification of oil aggregates, drawing attention to important characteristics of OcPA, marine oil snow (MOS), and OgPA.

Hydrostatic pressure enhances gas solubility and potentially alters toxicity and risks of oil and gas releases to deep-sea organisms. This study has two primary objectives. First, the aquatic hazard of dissolved hydrocarbon gases is characterized using results of previously published laboratory and field studies and modeling. The target lipid model (TLM) is used to predict effects at ambient pressure, and results are compared to effect concentrations derived from extrapolation of liquid alkane hazard data. Second, existing literature data are used to quantify and predict pressure effects on toxicity using an extension of the TLM framework. Results indicate elevated pressure mitigates narcosis, particularly for sensitive species. A simple adjustment is proposed to allow TLM-based estimates of acute effect and TLM-derived HC5 values (concentrations intended to provide 95% species protection) for oil or gas constituents to be calculated at depth. Future applications, and opportunities and challenges for providing validation, are discussed.

The performance of oil spill models is strongly influenced by multiple parameters. In this study, we explored the ability of a genetic algorithm (GA) to determine optimal parameters without the need for time-consuming manual attempts. An evaluation function integrating the percentage of coincidence between the predicted polluted area and the observed spill area was proposed for measuring the performance of a Lagrangian oil particle model. To maximise the objective function, the oil spill was run numerous times with continuously optimised parameters. After many generations, the GA effectively reduced discrepancies between model results and observations of a real oil spill. Subsequent validation indicated that the oil spill model predicted oil slick patterns with reasonable accuracy when equipped with optimal parameters. Furthermore, multiple objective optimisation for observations at different times contributed to better model performance.

The Olive Ridley marine turtle (Lepidochelys olivacea) is characterized by individual morphological variability in the number and shape of scutes. The influence of pollutants on developmental instability and one of its consequences, the asymmetry of individuals, has been demonstrated in several species, especially invertebrates and some birds. However, the use of this asymmetry as a biomarker of contamination in adult individuals has never been explored. We developed an index to quantify developmental instability (DIx) based on the number and relative size of costal carapace scutes. The link between DIx and inorganic elements concentrations was explored in various tissues of stranded turtles from the Southern Mexican Pacific. The relationships between adult contamination and DIx could directly or indirectly reflect (i) the disruption of metal elimination in the adult stage dependent on embryonic perturbation and thus determining DIx, (ii) the difference in metal absorption dependent on DIx status, or (iii) DIx linked to other unknown factors.