Very low sulfur fuel oil spilled from the MV Wakashio in 2020 remains in sediments in a Mauritius mangrove ecosystem nearly three years after the grounding.

The oil spill resulting from the grounding of the MV Wakashio on a reef off the coast of Mauritius in July 2020 was the world's first major spillage of Very Low Sulfur Fuel Oil (VLSFO) since the implementation of a Global Sulfur Cap from January 2020. In this study, we examine sediments collected in March 2023 from two Mauritius mangrove systems. Analyses by both gas chromatography-mass spectrometry and comprehensive two-dimensional gas chromatography confirmed, by comparison of molecular biomarkers, the presence of Wakashio VLSFO in one of the mangrove systems.

Phytoremediation Potential of Azolla filiculoides: Uptake and Toxicity of Seven Per- and Polyfluoroalkyl Substances (PFAS) at Environmentally Relevant Water Concentrations.

Environmental contamination of aquatic systems by per- and polyfluoroalkyl substances (PFAS) has generated significant health concerns. Remediation of contaminated sites such as the fire-fighting emergency training grounds that use aqueous film-forming foams is a high priority. Phytoremediation may help play a part in removing PFAS from such contaminated waters.

Groundwater is a hidden global keystone ecosystem.

Groundwater is a vital ecosystem of the global water cycle, hosting unique biodiversity and providing essential services to societies. Despite being the largest unfrozen freshwater resource, in a period of depletion by extraction and pollution, groundwater environments have been repeatedly overlooked in global biodiversity conservation agendas. Disregarding the importance of groundwater as an ecosystem ignores its critical role in preserving surface biomes.

Effects of carbon source addition in rearing water on sediment characteristics, growth and health of cultured marron (Cherax cainii).

Carbon sources are considered as critical input for the health and immunity of aquatic animals. The present study investigated the impact of different carbon sources on water quality parameters, carbon to nitrogen (C/N) ratio and microbial community in sediments, and health responses of marron (Cherax cainii) under laboratory conditions. Following one week of acclimation, 120 marron were randomly assigned to 12 experimental tanks.

Do distributions of diamondoid hydrocarbons accumulated in oil-contaminated fish tissues help to identify the sources of oil?

Identifying the sources of environmental oil contamination can be challenging, especially for oil in motile organisms such as fish. Lipophilic hydrocarbons from oil can bioaccumulate in fish adipose tissue and potentially provide a forensic "fingerprint" of the original oil. Herein, diamondoid hydrocarbon distributions were employed to provide such fingerprints.

Fish Fingerprinting: Identifying Crude Oil Pollutants using Bicyclic Sesquiterpanes (Bicyclanes) in the Tissues of Exposed Fish.

In the present study, we investigated the possibility of identifying the source oils of exposed fish using ratios of bicyclic sesquiterpane (bicyclane) chemical biomarkers. In the event of an oil spill, identification of source oil(s) for assessment, or for litigation purposes, typically uses diagnostic ratios of chemical biomarkers to produce characteristic oil "fingerprints." Although this has been applied in identifying oil residues in sediments, water, and sessile filtering organisms, so far as we are aware this has never been successfully demonstrated for oil-exposed fish.

Gut Microbiome as a Potential Biomarker in Fish: Dietary Exposure to Petroleum Hydrocarbons and Metals, Metabolic Functions and Cytokine Expression in Juvenile .

The gut microbiome of fish contains core taxa whose relative abundances are modulated in response to diet, environmental factors, and exposure to toxicogenic chemicals, influencing the health of the host fish. Recent advances in genomics and metabolomics have suggested the potential of microbiome analysis as a biomarker for exposure to toxicogenic compounds. In this 35-day laboratory study, 16S RNA sequencing and multivariate analysis were used to explore changes in the gut microbiome of juvenile exposed to dietary sub-lethal doses of three metals: vanadium (20 mg/kg), nickel (480 mg/kg), and iron (470 mg/kg), and to two oils: bunker C heavy fuel oil (HFO) (1% w/w) and Montara, a typical Australian medium crude oil (ACO) (1% w/w).

Characterizations and comparison of low sulfur fuel oils compliant with 2020 global sulfur cap regulation for international shipping.

The International Marine Organization 2020 Global Sulfur Cap requires ships to burn fuels with <0.50% S and some countries require <0.10% S in certain Sulfur Emission Control Areas but little is known about these new types of fuels.

Zeolite mediated processing of nitrogenous waste in the rearing environment influences gut and sediment microbial community in freshwater crayfish (Cherax cainii) culture.

Zeolite is known to uptake toxic metals and filter nitrogenous waste from aquaculture effluents. The present study aimed to investigate the impacts of zeolite in three different applications namely, dietary zeolite (DZ), suspended zeolite (SZ) in the water column, and a combination of both (DZSZ) relative to unexposed freshwater crayfish, marron (control). At the end of the 56-days trial, the impact was assessed in terms of characterization of microbial communities in the culture environment and the intestine of marron.

Multivariate analysis of otolith microchemistry can discriminate the source of oil contamination in exposed fish.

The uptake of metals into the aragonite lattice of the fish otolith (ear-bone) has been used for decades as a historical record of exposure to metals in polluted environments. The relative abundance of two metals in particular, Ni and V, are used in forensic chemical analysis of crude oils to assist in confirming its origin. In this study we investigate the potential for metal accumulation in otoliths to act as a biomarker of exposure to crude oil.

Metal(loid) pollution, not urbanisation nor parasites predicts low body condition in a wetland bioindicator snake.

Urban ecosystems and remnant habitat 'islands' therein, provide important strongholds for many wildlife species including those of conservation significance. However, the persistence of these habitats can be undermined if their structure and function are too severely disrupted. Urban wetlands, specifically, are usually degraded by a monoculture of invasive vegetation, disrupted hydrology, and chronic-contamination from a suite of anthropogenic pollutants.

Bioindicator snake shows genomic signatures of natural and anthropogenic barriers to gene flow.

Urbanisation alters landscapes, introduces wildlife to novel stressors, and fragments habitats into remnant 'islands'. Within these islands, isolated wildlife populations can experience genetic drift and subsequently suffer from inbreeding depression and reduced adaptive potential. The Western tiger snake (Notechis scutatus occidentalis) is a predator of wetlands in the Swan Coastal Plain, a unique bioregion that has suffered substantial degradation through the development of the city of Perth, Western Australia.

MV Wakashio grounding incident in Mauritius 2020: The world's first major spillage of Very Low Sulfur Fuel Oil.

Very Low Sulfur Fuel Oils (VSLFO, <0.5% S) are a new class of marine fuel oils, introduced to meet recent International Maritime Organization regulations. The MV Wakashio was reported to have released 1000 t of VLSFO when it grounded on a reef in Mauritius on 25th July 2020.

Discriminating source of oil contamination in teleost fish, Lates calcarifer, using multivariate analysis of a suite of physiological and behavioral biomarkers.

The release of petroleum hydrocarbons into the environment from natural seeps, well blowouts, pipeline leaks, shipping accidents and deliberate tank washing poses an ongoing threat to marine ecosystems. Distinguishing the source of oil contamination in exposed biota can be relatively straightforward if samples of the oil are available but, in their absence, such discrimination in fish poses a major challenge. The use of physiological and behavioral biomarker analysis provides a useful tool to describe sub-lethal effects of toxicant exposure.

Two independent approaches to assessing the constancy of evaporative water loss for birds under varying evaporative conditions.

We examine here the effects on evaporative water loss, at and below thermoneutrality, of perturbing the evaporative environment for the red-capped parrot (Purpureicephalus spurius) by modifying the ambient relative humidity or the diffusive properties of the ambient environment using a helium‑oxygen mix (helox). We found that evaporative water loss did not change with relative humidity at an ambient temperature of 30 °C, but there was a negative relationship for evaporative water loss with relative humidity at 20 and 25 °C. The evaporative water loss per water vapour pressure deficit between the bird and its ambient environment was not constant with relative humidity, as would be expected for a physical effect (slope = 0); rather there was a significant positive relationship with relative humidity at ambient temperatures of 25 and 30 °C.

A Mixture of Manganese, Silica and Phosphorus Supplementation Alters the Plankton Density, Species Diversity, Gut Microbiota and Improved the Health Status of Cultured Marron (Cherax cainii, Austin and Ryan, 2002).

Trace element supplementation to the freshwater environment can influence the plankton density and species diversity, contributing to the nutrition of aquaculture species, especially during the juvenile stage. An experiment was conducted under laboratory conditions to evaluate the effects of supplementing different mixtures of manganese, silica and phosphorus on the plankton density and species diversity and their impact on cultured juvenile marron (Cherax cainii, Austin and Ryan, 2002). Manganese, silica and phosphorus in concentrations of 0.

Temporal variations and pond age effect on plankton communities in semi-intensive freshwater marron ( Austin and Ryan, 2002) earthen aquaculture ponds in Western Australia.

The abundance and diversity of the plankton community represents the health of the aquatic ecosystem, and plays an important role in the growth of cultured animals under aquaculture conditions. The temporal variations of plankton abundance, taxonomic composition, diversity, evenness and species richness were studied in three old and three new semi-intensive marron ( Austin and Ryan, 2002) ponds. Water parameters such as temperature, dissolved oxygen, pH, turbidity, TAN, nitrite, nitrate and reactive phosphate were recorded, and plankton samples were collected every two months, for one year of juvenile production cycle.

A quarter century of recovery of the whelk Thais orbita from tributyltin pollution off Perth, Western Australia.

Imposex is a condition in which females of dioecious marine snails develop rudimentary male characteristics. It is caused by tributyltin (TBT) used as an antifoulant in vessel paints since the late 1960s. Following the 2008 international ban on TBT, a decreasing rate of imposex has been observed worldwide.

Metabolomics Provide Sensitive Insights into the Impacts of Low Level Environmental Contamination on Fish Health-A Pilot Study.

This exploratory study aims to investigate the health of sand flathead () sampled from five sites in Port Phillip Bay, Australia using gas chromatography-mass spectrometry (GC-MS) metabolomics approaches. Three of the sites were the recipients of industrial, agricultural, and urban run-off and were considered urban sites, while the remaining two sites were remote from contaminant inputs, and hence classed as rural sites. Morphological parameters as well as polar and free fatty acid metabolites were used to investigate inter-site differences in fish health.

Investigating the role of urbanisation, wetlands and climatic conditions in nematode parasitism in a large Australian elapid snake.

Tiger snakes () in wetlands of South-West Western Australia (SW WA) are commonly parasitised by the nematode . Host-parasite interactions are complex and can potentially be impacted by factors such as urbanisation or climate. We assessed whether urbanisation, distance to wetland sites, and climatic factors have influenced parasitism in tiger snakes from specimens collected over the last century.

First report of intersex in a lutjanid: the goldband snapper Pristipomoides multidens.

This is the first report of intersex in a lutjanid species, the goldband snapper Pristipomoides multidens, in which the gonads of a male fish contain multifocal oocytes scattered among testicular tissue. The incidence rate of intersex was low (<1.0%), with oocytes observed in the testes of only two of 206 male fish examined.

Biomarker responses and PAH ratios in fish inhabiting an estuarine urban waterway.

Many cities worldwide are established adjacent to estuaries and their catchments resulting in estuarine contamination due to intense anthropogenic activities. The aim of this study was to evaluate if fish living in an estuarine urban waterway were affected by contamination, via the measurement of a suite of biomarkers of fish health. Black bream (Acanthopagrus butcheri) were sampled in a small urban embayment and a suite of biomarkers of fish health measured.

Otolith microchemistry: Insights into bioavailable pollutants in a man-made, urban inlet.

Black bream (Acanthopagrus butcheri) were collected from an artificial inlet, Claisebrook Cove, Western Australia. Claisebrook Cove is adjacent to an historic contaminated site that was remediated during the 1990s. It was later identified as a priority area due to elevated levels of sediment contaminants including Zn, Cu, and Pb.