This study collected site-specific data that are relevant to a small-scale artisanal seagrass fishery, incorporating measures such as reported catch landings, gleaning, tourism, and downstream economic values. The seagrass habitat was determined to have a value of US$57 731.80 (RM242 473.58) per hectare per year and highlighted the advantages of incorporating anthropological and local knowledge in economic assessments of natural habitats.

Seagrasses remove and bury CO₂ as sedimentary organic matter in sufficient amounts to mitigate global warming. However, a 2-year sediment-incubation study indicated that 50% could be lost over climatic time scales, forming greenhouse gases such as CO₂ and methane. This could lead to underestimated emissions within a carbon cap and trade market, if such losses are not taken into account.

Seagrasses in tropical regions are plants that live in clean and transparent coastal areas associated with coral reefs. Thalassia testudinum seagrass is known as turtle grass because it is consumed by sea turtles. The growth of the human population in coastal regions is associated with the contamination of the coastal zone as a result of the dumping of inorganic and organic waste, which brings with it an environmental pressure on these seagrass beds and, in extreme cases, the loss of this marine ecosystem.

Halophila ovalis was subjected to shading treatments for 12 weeks to investigate the effects of reduced light level on seagrass morphology, chlorophyll concentration and optimal temperatures for net productivity. Shaded seagrasses experienced reductions in shoot density and leaf size, and increases in chlorophyll concentration. The range of optimal temperatures for net productivity did not vary with light availability.

This study documents early evidence of microplastics attached to several species of macrophytes (seaweeds and seagrasses) by measuring the amount of microplastic adhered to their surfaces. Microplastics can enter the food web when herbivores graze on these contaminated macrophytes.

Contributions of the water column and epiphytic load to light reduction in a Cymodocea rotundata meadow were quantified through field deployments, spectrometry and modelling of derived data. The relative contribution to light attenuation by epiphytic biomass was greater in clearer waters than in turbid waters. However, as turbidity increases, the contribution of epiphyte to light reduction increases exponentially.

In the present study, we examined the status of the seed banks of three common seagrass species in Singapore and attempted to identify potential drivers of seed abundance. Our results showed that the seed banks in many of the meadows surveyed are depauperate, with few species setting viable seed, low seed densities, and poor seed persistency. Our study has highlighted that, owing to these depauperate seed banks, seagrass meadows along the urban coastline of Singapore are vulnerable to future disturbances.

This study shows that current thresholds designed to protect the health of streams in South Australia need to be more stringent. We used a type of algae known as diatoms to assess whether the concentration of salt and phosphorus affected the species found in South Australian streams. The species composition changed at salinity and phosphorus concentrations well below existing thresholds.

Two low-cost (less than A$10 000) commercially available towed video and remotely operated vehicles were compared for their abilities to collect photographs of marine habitats and videos of fish assemblages. Both systems performed equally well for these purposes, but towed video was simpler to operate and required significantly less time to collect data.

Murray crayfish (Euastacus armatus) were historically abundant in Australia’s Murray–Darling Basin, but river regulation, pollution and overfishing have reduced their range and abundance. Angler surveys quantified recreational catch, effort and harvest of crayfish in the Murrumbidgee River, which were then used to predict likely outcomes from changing harvest regulations. The model predicted that the change to a harvest-slot length limit would stabilise the population in the first 25 years and slowly increase it thereafter.

A study of biological communities associated with the last known remaining native flat oyster reefs, in north-eastern Tasmania, Australia, found that they contained greater biodiversity of fishes and invertebrates and three times the abundance compared with surrounding soft sediment sites. These diverse animal assemblages were probably lost when oyster reefs disappeared around southern Australia after European settlement.

Grapsoid assemblages were surveyed in six mangrove sites in the Malay Peninsula. Species composition differed among sites with different types of substrate and forest area. Most species appear to be stenotopic or have patchy distribution. Management actions should consider the marked variability in species composition and environmental factors, to prevent local extinctions of species and sustainably manage these ecosystems ecological diversity.

The seagrass Zostera muelleri has, in recent decades, declined massively along the eastern coastline of Australia. To restore this important marine plant, we tested multiple techniques for transplanting mature adult seagrass shoots. Results showed that transplantation works best when shoots are anchored and bioturbating animals are excluded. However, in areas where grazing fish are present, the transplanted shoots should be further protected by placement of cages above the shoots.

A series of experiments conducted in a flow-through tank revealed that current velocity, temperature and oil thickness significant affect the refloating process of an oil patty. Furthermore, an empirical model was introduced and found to be closely consistent with the experimental data. The results can be widely used in practice.

Marine fish are a major source of human and seabird exposure to methylmercury. Mercury concentrations vary according to the trophic level of commercially important marine fish from South China Sea. In this study, low biomagnification of mercury in the fish food chain is demonstrated in the South China Sea, and factors related to mercury concentrations are discussed.

After incubating river water with carbon-13-labelled glyphosate for 6 days, we found significant shifts in bacterioplankton community composition. Bacterial richness and diversity were decreased in the 100 µg L^–1 glyphosate treatment, where 1.2% of glyphosate was converted to AMPA and a significant enrichment of carbon-13 in the bacterial biomass was detected. These results suggest that glyphosate in the water is likely more resistant to degradation than reported.

We explored a multilevel approach to providing a monitoring tool to detect teratogens dissolved in waters by extending the potential of tracking human-mediated detrimental environmental changes using overlapping information from short-term responses in an embryo toxicological assay based on freshwater polyps and two biotic indices based on plants and invertebrates. The findings show that the embryo toxicological assay may be considered a good early-warning system of potential teratogenic threats.