Marine and Freshwater Research最新文献

With escalating global climate change, regional flood disasters have become increasingly prevalent. Precipitation, as a primary influencing factor, has garnered significant attention.

This study is based on precipitation data to investigate the spatiotemporal characteristics of precipitation in the middle and lower reaches of Yangtze River Basin (MLYB), trying to explore more concise methods for precipitation forecasting.

Statistical methods were employed to analyse historical precipitation patterns, followed by forecasting future trends using statistical time series models.

Precipitation in the MLYB exhibited a decreasing trend during 1961–2010, which shifted to an increasing trend after 2011, becoming more pronounced since 2017. Precipitation patterns in the MLYB were clearly increasing in the east and decreasing in the west, with the Taihu Basin showing the greatest rise. The ARIMA model predicted a significant increase in precipitation after 2022.

In recent years, precipitation in the MLYB has significantly increased, especially in downstream areas. Although the ARIMA model offers an effective and reasonably simple method for short-term forecast, it struggles with complex terrain influences.

These findings provide a theoretical basis for flood prevention in the MLYB, as well as a reference for precipitation prediction simulations in data-limited regions.

Ongoing learning is essential for freshwater ecosystem management, but there is limited documentation of successful integration into management.

We aimed to increase learning-related understanding required for effective adaptive management of water for the environment, in water-stressed and contested river systems.

We developed a learning approach (requisite learning) for managing water for the environment, demonstrated with real-world examples from the Macquarie River and Marshes, Australia.

Four co-existing, interdependent learning types enable effective management of water for the environment: (1) ‘adjusting routines’, (2) ‘adaptive assessment’, (3) ‘changing practice’, and (4) ‘transforming governance’, exemplified by using management of water for the environment for the Macquarie River and Marshes. To enable and improve requisite learning, stakeholder social learning, and flexibility in governance arrangements, must develop.

Ongoing learning is essential for effective adaptive management. Understanding what requisite learning is and how capacity can be improved, will help achieve outcomes required of managing water for the environment.

Effective management of water for the environment is essential, transparently delivering environmental outcomes and accounting for decision-making. To do this, we need to improve explicit learning understanding by nurturing learning mandates and champions, fostering social learning, increasing flexibility in governance arrangements, and institutionalising learning.

Published evidence suggests recruitment of floodplain trees is declining in the northern Murray–Darling Basin (MDB) and that this is linked to river flow.

We investigated the reproductive phenology of Eucalyptus camaldulensis and Eucalyptus coolabah to better understand tree reproductive cycles and the influence of rainfall and flow on seed production.

We surveyed phenological events (bud, flower and fruit production) over 6 years, at nine sites along the Condamine–Balonne River and examined correlations between these events and meteorological parameters.

For both species, event timing was consistent across sites and years and event relative abundance scores were different between years. Bud abundance was correlated with rainfall, flooding and warming temperatures and E. coolabah produced additional bud crops after floods.

The timing of events did not differ significantly from published results for the southern MDB. Rainfall, river flows and flooding in spring resulted in more abundant bud crops in E. camaldulensis and E. coolabah, and subsequently more abundant fruit crops. Fruit dehiscence coincided with summer–autumn flooding, which provides seed for germination. Genetic and physiological factors may also influence the observed pattern.

These results will inform water planning in Queensland, Commonwealth Environmental Water Holder watering actions and long-term watering plans in the northern MDB.

Owing to the multiple functions of lipids and fatty acids in organisms, lipid composition can be used as an environmental biomarker of the health status of sentinel organisms in monitoring studies of aquatic ecosystems.

To study the lipid profile of the mussel Mytilus galloprovincialis from the Black Sea and to identify lipid compounds as environmental biomarkers.

Lipid and fatty acid compositions in the gills and digestive glands of mussels were analysed by chromatography.

Membrane-state fatty acid indices in phospholipids were quite stable in all the mussels examined. The fatty acid composition of triacylglycerols is primarily an indicator of the food source for mussels. The selective retention of arachidonic acid as well as the accumulation of non-methylene-interrupted fatty acids in mussels are assumed to be biomarkers of environmental stress.

The presence of regulatory mechanisms ensuring the stability of the membrane structure was confirmed in all studied mussels.

The content of minor phospholipid fractions (namely, phosphatidylinositol and sphingomyelin) and the distribution of some fatty acids and their indices among lipid classes in the gills and digestive glands of M. galloprovincialis can be used in the assessment of the health status of sentinel organisms.

Spawning beaches are important for coastal horseshoe crabs, Tachypleus gigas (Müller, 1785), to sustain their population. Over time, T. gigas natural spawning area has gradually diminished owing to human and natural causes. T. gigas is being artificially bred in captivity to enhance its population.

The study aims to determine the T. gigas spawning preference for three different sediment sizes.

Spawning experiments were carried out in an indoor concrete tank representing an artificial spawning ground, consisting of three combinations of sediment sizes: coarse, medium and fine. The spawning of 45 pairs of T. gigas samples was observed within 3 h, the nests were marked and excavated on the next day. The number of eggs per nest was counted individually after being cleaned.

The 45 pairs of T. gigas produced 27,266–30,859 eggs. Among these, on the basis of the number of nests produced, T. gigas prefers to spawn in medium to coarse sediment with a particle-size range of 0.25–1.00 mm.

Our findings indicated that medium to coarse sediments are optimal for T. gigas spawning in artificial spawning grounds, because they could produce a high number of nests and eggs, increasing the number of juveniles released.

These results could be used as a baseline for the conservation management of T. gigas in captivity.

Rapid urbanisation and economic growth have intensified challenges such as water scarcity and flood management in urban areas. Addressing these issues requires enhanced water-management strategies to support sustainable urban development.

This study aims to refine the framework for water-saving initiatives in cities, crucial for implementing stringent water-management practices and addressing complex water challenges, thereby contributing to sustainable economic and social progress.

Using the analytic hierarchy process, a comprehensive evaluation model for urban water-resource management was developed. This model integrates an evaluation index system that considers social, economic and environmental benefits, promoting sustainable development and the circular economy.

The developed model successfully enables both quantitative and qualitative assessments of urban water-resource management strategies. It offers a more streamlined and accurate methodology for evaluating the regional water-resource carrying capacity, surpassing the precision and usability of existing models.

The study underscores the critical role of advanced water-resource management strategies in urban environments. It demonstrated that integrated approaches are essential for addressing the multifaceted challenges of urban water management and for promoting urban sustainability.

This research provides actionable insights for policymakers, highlighting the necessity of incorporating comprehensive evaluation models in urban water management. By emphasising the integration of social, economic and environmental benefits, it supports the advancement of sustainable water-use practices and promotes ecological and social equity.

No consensus has yet been formed on project development in lake-water conservancy on aspects such as lake quality, ecological environment, rural economy, social culture, leisure living environment and leisure aspirations due to the current lack of comprehensive discussion.

This study mainly uses the case of Sun Moon Lake in Taiwan to verify the impact of lake-tourism optimisation and water-conservancy projects on the rural economy, water quality, ecology and sustainable development of tourism for local young people in the area around the lake.

We employed open-sampling questionnaires and semistructured interviews to collect data and conducted multivariate analysis.

The study investigated the hypothesis that optimising water-conservancy projects for lake tourism creates a stable leisure and tourism environment in rural areas, enhances visibility, and increases emotional exchanges and the preservation of historic sites. However, problems such as excessive tourism waste and a lack of public facilities negatively affect local young consumers’ willingness to engage in tourism activities.

Improving problems in the villages, ecology and natural environment surrounding lakes that are being conserved can increase young local individuals’ willingness to engage in and share experiences of tourism activities.

If the local government can improve the issues of protected villages, ecology and the natural environment around the lake, it can increase the willingness of local young people to participate in and share their experiences in tourism activities.

Many shallow lakes are degraded to the point where they are permanently turbid and macrophytes no longer grow. Without the macrophytes, wave action resuspends lakebed sediments, and a feedback loop is set up, trapping the lake in a degraded state. Multiple restoration actions are required to reverse this process, including catchment management and in-lake actions to remove barriers to establishing native vegetation. In particular, when macrophytes have been lost for a long time, the native seedbank may be depauperate and limit re-establishment opportunities. Re-establishment of submerged vegetation is critical to the restoration of lakes, but to date there have been few efforts to actively do this. There are significant barriers preventing this goal, relating to poor water quality, low-density sediments and the browsing impacts of fish and waterfowl, that will be further exacerbated by the warmer temperatures and more extreme weather events forecast under climate change. A combination of experimental and field studies determining optimal environmental ranges of different macrophyte species, methods to culture en masse and techniques to promote sufficient water clarity and sediment density to sustain macrophytes are necessary. Once minimum vegetation cover thresholds are exceeded, sustainable restoration to a macrophyte-dominated clear-water state should eventuate.

Dryland rivers are unique ecosystems, where drought and flood play an important role in shaping the ecosystem. River regulation has altered the natural flow regime in many of these systems, affecting migration cues and connectivity for many species.

To quantify the discharge-related movements of Murray cod and golden perch within the Condamine–Balonne River subject to differing levels of river regulation.

We quantified flow regime variability, river regulation and fish movement to develop generalised additive mixed models to predict movement probability for Murray cod and golden perch.

Both species showed strong positive relationships between discharge and movement. Murray cod did not show any association with river regulation; however, medium-sized individuals were significantly more likely to move than were smaller or larger fish. Golden perch movements varied among levels of regulation, were more likely to move as body weight increased and showed seasonality of movement, moving less during winter.

This study presents the largely unobserved movement behaviours of fish across a gradient of river regulation and environmental conditions in the northern Murray–Darling Basin.

This information is valuable for informing policy and management decisions that may affect species’ life-history requirements in analogous river systems.

Dryland wetland vegetation is, paradoxically, both highly sensitive and extremely resilient to environmental change. In the short-term, rapid responses of wetland biota and ecological processes to wetting and drying, which influence ecosystem structure and function, enable rapid reproduction which enhances long-term resilience. However, over longer periods, mechanisms such as seed dormancy and persistent seed and egg banks enable dryland wetland ecosystems to recover after major environmental perturbations such as mega-droughts or wildfire. Climate change is likely to have a significant effect on key drivers of ecological response in dryland wetlands, including hydrology and its interface with other climatic stimuli, e.g. temperature, as well as the frequency and intensity of extreme events. Like species, wetland ecosystems may respond to climate change in three main ways, namely, disappear, persist without significant adjustment, or transform. Here, we consider the conditions under which each of these responses may eventuate for dryland wetlands, by using wetland vegetation of the northern Murray–Darling Basin Australia, as a case study. We also explore what wetland transformation might entail in this region in terms of wetland ecological character and the key values this supports. Finally, we consider the implications for wetland policy and management at present and as trajectories of wetland change unfold.