Marine and Freshwater Research

We investigated whether environmental flows and stocking in combination support a population of a freshwater fish more effectively and cost efficiently than does either action in isolation under various climate-change scenarios. Our model suggests that the application of environmental flows was highly effective in all but the most-extreme climate-change scenarios. Alternatively, the value of stocking increased with an increasing severity of climate change. Under severe climate-change scenarios, such interventions may be successful only to a point.

Transboundary water management has often been obstructed by tensions among the different nation-states. Better transboundary management of Brahmaputra requires a new direction from the current situation of fragmented cooperation, conflicts and disputes among China, India, Bhutan and Bangladesh, and increasing threats of climate change. We find that hydropower-supported energy transitions for clean and affordable energy supply meet the needs and expectations of all nations, especially under the threats of climate change.

An estimation of economic values as perceived by the primary stakeholders of Loktak Lake was conducted employing discrete choice experiment method. Proper accounting of economic values is assumed to be essential for better management of wetland resources. It has been found that there exist considerable levels of observed and unobserved preference heterogeneity among the stakeholders. The willingness to pay, as expressed by local communities, for better management of Loktak Lake highlighted the importance of developing a more inclusive approach in the management of the wetland.

The finescale triggerfish, Balistes polylepis, plays an important role by feeding on a wide range of resources and, hence, generating trophic interactions with numerous species. The most important prey items at two sites in the Gulf of California were the colonial ascidian Lissoclinum fragile at Las Ánimas and the Xanthidae family at San Juan de la Costa.

This study observed the formation of a pair within a group of grey triggerfish (Balistes capriscus) in the laboratory, culminating in reproduction and enabling studies on the larviculture of the species. The results indicated that it is possible to keep small groups of breeders in captivity, but the individualisation of couples may be necessary, because of the aggressiveness towards other individuals. The hatchery phase is still a strong limiting factor for the artificial propagation of the species, because it demonstrates specificity regarding the first exogenous food.

Microplastic (MP) contamination is a threat for freshwater systems worldwide. We evaluated MPs in different insect species, sediment and water in a wastewater basin in Sohag, Egypt. The collector–gatherers (Chironomidae) recorded the highest MP load, the highest bioaccumulation factor (BCF), and the biota-sediment accumulation factor (BSAF), whereas predators (Aeshnidae) had the lowest MP lode. Polyester fibres were the dominant polymer in both water and sediment, and the only type in insects. We concluded that feeding guilds of the insect species may play a role in MP load.

We have assessed possible spatial stock structure of a catfish (Rita rita) in the Ganges Basin. Multiple approaches, namely, truss morphometry, otolith chemistry and otolith shape, were used to suggest spatial structuring. Each of the methods delineated the fish groups from different sampling locations as separate stocks.

Otolith nitrogen isotope ratios represent the nitrogen source of fish because the isotope ratios are consistent between diet and otolith. Carbon isotope ratio is significantly higher in otolith organic matter than that in diet. The isotope ratios of otolith organic matter are useful for studying feeding ecology of fishes, especially when metabolic tissues or diet are not available.

The Ramsar Convention on Wetlands is a critical tool in global efforts to conserve wetlands and their myriad values. In this paper, we pilot the Rapid Ramsar Management Effectiveness Evaluation Tool in the Caroni Swamp Ramsar Site in Trinidad. We found serious gaps in capacity and institutional context that undermine implementation of the Ramsar Convention in the twin island nation.

Native fish populations in Australia’s Murray–Darling Basin have experienced severe declines since European settlement. We quantified trends in populations of six large-bodied fish species in New South Wales from 1994 to 2022. Results showed strong inter-annual variation in relative abundance, biomass and population structure for all species, with little evidence of continued decline of native species since the 1990s.

In view of early strength performance required by silt solidification projects for space reduction, it was investigated whether the early strength material, sulfoaluminate cement, used during sludge solidification treatment in sewage treatment plants, exerts early strength effects on desilting. The occurrence mechanism of early strength is discussed from the perspective of moisture transformation. With sediments dredged from Dalian Bay as the object, the strength, deformation and moisture transformation amount of solidified sludge were practically measured and analysed with reference to Portland cement.

Urbanisation leads to water-resource problems; monitoring of urban water resources is needed for urban development. This paper systematically introduces the application of geostatistics and remote sensing for monitoring urban water resources. We used bibliometrics to analyse the existing literature, discussed the use of remote sensing and geostatistics to improve urban water-resource monitoring capacity. It is obvious that improving the accuracy of urban water-resource monitoring is needed, so as to promote the city to use water resources better.

Antibiotics are a new pollutant with biological activity, and are one of the pollutants in pharmaceuticals and personal-care products (PPCPs). In recent decades, the presence and fate of antibiotics in water environment have received special attention because of their persistence, resistance to biodegradation and the potential risks to ecological and human health. This review briefly addresses the current state of knowledge concerning the input sources, and the distribution characteristics of antibiotics in China, and summarised the degradation and removal methods applied to the antibiotics

In this study, the comprehensive standard evaluation system of ‘Happy River’ was constructed by using the analytic hierarchy process (AHP) for the first time, and the empirical study of several typical rivers (located in Shaoxing City, China) was conducted. On this basis, the countermeasures and suggestions for promoting the construction of ‘Happy River’ are put forward, which provides a reference example for the sustainable management of rivers.

The aquatic ecological health assessment and the influencing mechanism have attracted great attention of researchers. This study assessed the aquatic ecological health of Poyang Lake and analysed the influencing factors based on. The results showed that the aquatic ecological health was mainly ‘good’, and remarkable seasonal differences were observed. Our results indicated that scholars and policymakers should focus on both nutrient concentrations and hydrological conditions.

Controlling the inputs of nutrients, one of the main sources of lake pollution from inflow rivers, is an important way to protect lakes. We obtained a whole picture of spatiotemporal variation of water quality in Gehu lake and inflow rivers, analysed the relationship between them using BATHTUB model and discussed collaborative control by setting up different scenarios. Our findings help provide effective control of water quality in inflow rivers and a guide for the environmental governance of Gehu Lake.

A well-designed layout of leisure-fishery (LF) industry can reduce resource-allocation costs, give play to regional advantages, and maximise utility. LF units in Zhejiang Province were selected as the research objects. The results showed significant differences in the distribution density among different cities. Traffic, market, and scenic-spot location significantly affected the distribution of LF units in Zhejiang Province.

The pressure–state–response (PSR) model was used to construct an evaluation index system for the health of the Futian mangrove wetland ecosystem, which adopted a comprehensive assessment model of wetland-ecosystem health, and predicted the impact trend of an alien species, sae sang, on the Futian mangrove wetland ecosystem.

In this study, significant biomagnification was shown for Hg, Mn, Pb and Sn in the fish food chain. Noticeable dilution was demonstrated for Cu and Cr. Unapparent trend of both biomagnification and biodilution was found for As, Se and Zn. The Se:Hg molar ratios exhibited noticeable species and spatial variation for the wild fish, whereas the antifouling reagent and surface applications might be the main sources of Sn and Pb contamination in fish.

The impact of dam construction on the regional climate has attracted great attention of researchers. This study evaluated the impact of a large-scale dam construction on regional precipitation. The regional precipitation data before and after the construction of the Xiaolangdi Dam and the Three Gorges Dam were analysed using geostatistical tools. It can be concluded that the establishment of the dam increased the precipitation value in this area. It is speculated that the larger dams will have greater precipitation.

Our study focused on quantifying the extent of ecological water-demand security of the Linghekou Reserve, investigating changes in the landscape pattern of the Linghekou Reserve during 2005–2019, evaluating the ecological water demand of the Linghekou Reserve from 2005 to 2019, and analysing the water-demand security of biological habitat as an important factor affecting the ecological water-demand security of the Linghekou wetland.