Indigenous people from the remote community Ngukurr, northern Australia, are concerned about the health risks associated with drinking water from freshwater billabongs. In response to these concerns, a cross-cultural (Indigenous knowledge and waterborne pathogen) assessment of water quality and drinking water safety was undertaken. Indigenous perspective aligned with the pathogen results, whereby billabongs were safer to drink from in the early dry season then the late dry season.

We have studied the antibiotic pollution in fish, crab–shrimp and crab ponds around Taihu Lake Basin, China. We also evaluated a risk assessment of antibiotics with regard to organisms.

This study assessed the heavy metal contamination of surface marine sediments in Makadi Bay on the Red Sea, Egypt. Different indices were used to assess the level of pollution (i.e. enrichment factor, contamination factor and geoaccumulation and soil pollution indices). The results indicate that heavy metals in the area do not pose a serious environmental risk, except for Pb and Cd.

In recovering methane from methane hydrate, methane gas may leak into the seawater, affecting ocean floor ecosystems. In this study, methane leakage was detected by analysing particulate methane monooxygenase (pmoA) genes in methane-oxidising bacteria. Differences in the number of pmoA genes reflected methane leakage from the sea floor, indicating that this method could be a very sensitive methane leak indicator.

Coral-reef ecosystems have been continuously affected by stress conditions, causing bleaching and death, allowing other competitors from the reef to use such space. We evaluated the short- and long-term changes in the cover of three reef coral genera over multi-year periods, some with abnormal temperature. Results showed that anomalies caused an ephemeral decrease in coral cover, with a remarkable presence of coralline algae. However, the communities eventually returned to their coral-dominated state, suggesting that these reef habitats are resilient to such episodes of abnormal seawater temperature.

We explored how different abiotic drivers interacted to affect recruitment in the river blackfish. We found that temperature was the primary variable that determined recruitment success, whereby highest recruitment happened in cooler streams. In addition, temperature was found to interact with riparian cover, with the highest recruitment found in cooler streams that also had high riparian cover.

In this study, we characterised the community of the main bycatch species in the squat lobster surveys. Four ecological groups were found that primarily differed in abundance but not species richness, suggesting a lack of spatial structure. We also created habitat suitability maps for the groups identified and discuss the effects of the environment on the distribution of the groups.

This study investigated how differences in carbon and nitrogen isotopes in food sources could affect these values in shrimp. The time needed for isotope values in shrimp to stabilise after a dietary shift was determined, and correlations between isotope values in feed and shrimp were calculated. The results will help refine stable isotope traceability technology.

In this study we investigated the reproductive traits of 150 tiger sharks caught off Reunion Island, including five gravid females. Sizes at maturity were estimated at 278.5 cm for males and 336 cm for females. Genetic polyandry was not evident, which is a rare finding in sharks.

Morphodifferentiation among four red mullet populations was examined. It was hypothesised that morphological differences are caused by diverse hydrodynamic features and maintained by geographical distance, and that morphological homogeneity is a result of habitat complexity. Overall, high structural complexity promotes low variation in red mullet body morphology, and geographical isolation constrains the diversification originating from different hydrodynamic conditions.

Plankton surveys of ice-covered temperate coastal lagoons are rarely conducted, probably due to logistical difficulties. In this study we surveyed plankton in the Baltic Vistula Lagoon while it was covered in ice in 2018. Environmental conditions were determined by freshwater and marine influences, and were related to the patchy distribution of both phyto- and zooplankton. There was a positive correlation between the biomass of phyto- and zooplankton.

Sawsharks are among the least-studied group of sharks, despite being frequent bycatch in many commercial fisheries. In this study we extracted commercial and observer catch data from various sources to determine spatiotemporal distribution patterns of two sympatric species of sawshark in south-eastern Australia. We found evidence for abundance hot spots near Bass Strait, although these species appear resilient to fishing pressures.

Determining the age of rockfish is difficult. Their otoliths (ear stones) have growth zones that are difficult to count. Hence, we used bomb-produced radiocarbon to confirm fish age independently. In redstripe rockfish there was a small probability of underageing; in harlequin rockfish there was a large probability that the fish were underaged; and in shortspine thornyhead and shortraker rockfish, the bomb-produced radiocarbon was probably not an effective tool.

Giant trevally (Caranx ignobilis) are an iconic reef fish common to tropical and subtropical waters from South Africa to Hawaii. Despite their broad range, importance as a top predator and attraction among anglers, the growth and lifespan remain largely undescribed. In this study, giant trevally were aged up to 25 years using otolith (ear stone) growth rings and bomb radiocarbon dating.

Regulation of lowland rivers can disrupt ecological processes occurring in the river–floodplain ecosystems, and environmental water can be delivered to affected wetlands to maintain productivity. We followed changes in the abundance of invertebrates after wetting in three mesocosm trials using soil from two wetlands from the north of the Murray–Darling Basin over 6-week periods. The results suggest that inundation of wetlands using environmental watering can achieve high productivity within a short time frame, within weeks.

Analysis of dusky flathead stock structure using multiple genetic marker types revealed the species has a panmictic stock, but this is affected by coastal geomorphology through effects on recruitment, as well as concomitant effects on genetic diversity. Our findings are discussed in the context of marine stocking for the species.