Conservation Of Freshwater Ecosystems Research Articles

An integrated methodological framework for the durable conservation of freshwater ecosystems: a case study in Colombia’s Caquetá River basin

Introduction: Although freshwater ecosystems encompass 12% of all known species, their study has achieved less progress in systematic conservation planning exercises compared with terrestrial and marine ecosystems. Moreover, little attention has been given to ecosystem services and cultural and spiritual values, which are pivotal in the long-term preservation of freshwater ecosystems. Conservation, restoration, and sustainable management actions within freshwater systems are currently addressed individually, underscoring the necessity of comprehensive methodological frameworks that holistically address the questions of where and how to conserve while integrating ecosystem services and cultural factors as conservation values.Methods: We propose a new methodological framework for the conservation of freshwater ecosystems that incorporates these elements and fulfills six prioritization criteria: 1) representativeness, 2) integrity, 3) importance, 4) rarity, 5) complementarity, and 6) connectivity. To illustrate the application of this approach, we conducted a regional study in the Caquetá River basin in Colombia.Results: By applying our methodological framework, we demonstrated that the Caquetá River basin hosts 518 distinct freshwater groups with unique characteristics that contribute to the maintenance of ecosystems and the preservation of their inherent values. Additionally, our analysis revealed that protection is the most effective conservation strategy for 77.4% of the Caquetá River basin, whereas restoration and sustainable management are suitable for 4.7% and 17.9% of the basin, respectively. The prioritized portfolio for the Caquetá River basin encompasses 80.1% of all freshwater groups, effectively meeting The Nature Conservancy’s proposed conservation objectives.Conclusion: This novel methodological framework provides a pragmatic approach to systematic conservation planning and answers the questions of both where and how to conserve.

Impacts of salinity stress caused by ballast water discharge on freshwater ecosystems

Global commodity trade and the transportation of goods rely heavily on shipping. But the discharge of large quantities of hypersaline ballast water carried by maritime vessels into freshwater ports, lakes, rivers and other water bodies cause salinity stress, which can be detrimental to native freshwater organisms. In this study, the effects of marine hypersaline ballast water discharge and the rate of discharge (abrupt vs. gradual) on inland freshwater lakes were assessed by observing changes in freshwater plankton communities under salinity stress. The findings indicate that increasing salinity has a negative impact on plankton community composition, density and biodiversity. Zooplankton were more sensitive to changes in salinity than phytoplankton through 10 consecutive days of experiments. Moreover, the plankton community showed some ability to recover itself at low salinities (S≤6.5 PSU). In terms of the rate of ballast water discharge, plankton were more likely to survive in aquatic environments with gradual changes in salinity than with abrupt changes. This research is of great significance for the scientific management of ballast water discharge in freshwater ports and the conservation of freshwater ecosystems.

Centering 30 × 30 conservation initiatives on freshwater ecosystems

Regional, national, and international 30 × 30 conservation initiatives would be strengthened by including a specific focus on freshwater ecosystem conservation that supplements terrestrial conservation strategies. Globally, freshwater habitats support essential biodiversity and ecosystem services, yet are being lost at disproportionately high rates relative to terrestrial systems. Making freshwater ecosystems an explicit focus of 30 × 30 initiatives would assist in curtailing these losses while advancing 30 × 30's mission to address climate change, economic sustainability, food security, and equitable outdoor access across a variety of landscapes. Here, we explain how fresh water can serve as a key piece of 30 × 30 conservation efforts. We emphasize that to address the challenges of traditional area‐based conservation programs, 30 × 30 should (1) focus on watershed‐scale conservation planning and (2) evaluate conserved areas based on five freshwater priorities: connectivity, watershed disturbance, flow alteration, water quality, and biodiversity. We use examples from the US state of California to illustrate how addressing freshwater systems can help guide 30 × 30 conservation.

Environmental DNA reveals anadromous river herring habitat use and recolonization after restoration of aquatic connectivity

AbstractRestoring and sustaining anadromous fish populations is a grand challenge in the conservation of freshwater ecosystems. Alewife Alosa pseudoharengus and Blueback Herring Alosa aestivalis are two closely related anadromous fish for which responses to fish passage restoration are poorly known. We used a targeted environmental DNA method to sample 17 major tributaries of the Chesapeake Bay, USA, to determine the spatial extent of habitat use during the spawning season and the associations of habitat use with watershed characteristics. To help understand responses to restoration of fish passage, the study included portions of eight watersheds where dam removals, fish ladders, or dam failures provided access to habitats that were previously inaccessible to anadromous fish. Overall, 27.5% of samples showed positive detections for river herring, including at least one sample in 16 of 17 tributaries sampled. The presence of both species combined was negatively associated with elevation (relative influence [RI] = 29.8%) and positively associated with a watershed area (RI = 14.5%) and percent cropland (13.6%) of the watershed. In species‐specific analyses, both Alewife (RI = 24.8%) and Blueback Herring (26.2%) presence was negatively associated with elevation, Alewife were more common in watersheds with high percentages of cropland (RI = 19.1%), whereas Blueback Herring were more common in streams with large watersheds (23.2%). The use of formerly blocked spawning habitats was generally greater upstream of sites where dams were removed (2%–100% of habitat used) compared with sites where fish ladders were installed (0%–66.8% of habitat used). The broad‐scale sampling enabled by eDNA methods made it possible to identify habitat use patterns that can be applied to prioritize future restoration efforts and predict species‐specific responses.

Enhancing whole-of-river conservation

We argue for improved conservation of freshwater ecosystems at catchment or eco-regional scales by explicit assignment of values to all river sections and wetlands, recognising current disturbance, and aiming for ‘no further harm’ to the commons. The need is indicated by the global deterioration of biodiversity and ecosystem services of rivers and wetlands, increasing demands on water and land resources, and climate change. Regional pressures include multiple jurisdictions, competing demands, piecemeal management, pollution and habitat impacts. Effective resource and conservation management needs to integrate multiple uses via governance of activities of stakeholders, recognising hydrogeomorphic, water quality and ecological properties of ecosystems. Complete ecological protection is impractical amidst water-resource and land-use development, but we suggest that all river reaches and wetlands be given a conservation rating based on habitat, biodiversity and connectivity values. We present a straightforward approach to spatial conservation rating of freshwaters, using hydrogeomorphic typology and assignment of conservation values on the basis of available information and expert elicitation. We illustrate the approach by using the large Burdekin River catchment in north-eastern Australia. This approach is complementary to more spatially focused conservation prioritisation and could greatly improve management for sustainability, reduce further decline in conservation values, and facilitate rehabilitation.

Adjustment of the methodological guidelines for establishing the permitted surface water abstraction and environmental flow for freshwater ecosystem conservation

Adjustment of the methodological guidelines for establishing the permitted surface water abstraction and environmental flow for freshwater ecosystem conservation

Best Practices for Monitoring and Assessing the Ecological Response to River Restoration

Nature-based solutions are widely advocated for freshwater ecosystem conservation and restoration. As increasing amounts of river restoration are undertaken, the need to understand the ecological response to different measures and where measures are best applied becomes more pressing. It is essential that appraisal methods follow a sound scientific approach. Here, experienced restoration appraisal experts review current best practice and academic knowledge to make recommendations and provide guidance that will enable practitioners to gather and analyse meaningful data, using scientific rigor to appraise restoration success. What should be monitored depends on the river type and the type and scale of intervention. By understanding how habitats are likely to change we can anticipate what species, life stages, and communities are likely to be affected. Monitoring should therefore be integrated and include both environmental/habitat and biota assessments. A robust scientific approach to monitoring and appraisal is resource intensive. We recommend that appraisal efforts be directed to where they will provide the greatest evidence, including ‘flagship’ restoration schemes for detailed long-term monitoring. Such an approach will provide the evidence needed to understand which restoration measures work where and ensure that they can be applied with confidence elsewhere.

River Connectivity is Crucial for Safeguarding Biodiversity but May be Socially Overlooked. Insights From Spanish University Students

The social value of natural aquatic ecosystems is very important to set management priorities. River connectivity is essential for the conservation of freshwater ecosystems because barriers alter both abiotic conditions and the biotic communities, compromising biodiversity; however, the appreciation of this river feature has been insufficiently considered in socio-environmental studies that are mainly focused on the acceptance of new dams. Here we used a willingness to pay approach to estimate the value of connectivity, native species, fish diversity (measured as functional diversity or as species richness), fish abundance and environmental quality in three groups of students of different educational background in Asturias (NW of Spain). As in other studies where they are more sensitive to environmental issues, educational sciences students would pay more to conserve and improve river conditions than students of other disciplines. Connectivity was the least valued river feature by students of educational and natural sciences, and the third (before biodiversity and fish abundance) by engineering students. We measured the same features on lowland reaches of four coastal rivers in the Bay of Biscay, and applied declared will amounts to model their appreciation. Differences between the river ranks obtained from functional diversity (that changes with non-native species) and species richness, and small differences between students of different disciplines in the gap between most and least preferred rivers arise from the model. This indicates the importance to involve diverse stakeholder sectors in decisions about rivers. The importance of river connectivity in the conservation of local biodiversity should be explained to general public, perhaps through environmental campaigns.

How does sublethal permethrin effect non-target aquatic organisms?

Permethrin is belonged to pyrethroids that are one of the substances developed as an alternative to pesticides. Permethrin, which is used especially in agriculture, can bioaccumulate in the water and sediment when mixed into aquatic ecosystems. For this reason, it is necessary to investigate the effect of this substance on aquatic organisms other than the target organism. The aim of this study was the determination of acute and sublethal effects as antioxidant enzyme levels on different organs and hemolymph biochemistry of the non-target aquatic organism, narrow-clawed crayfish (Astacus leptodactylus), after exposure to permethrin, one of the synthetic pyrethroid pesticides, contaminating aquatic ecosystems due to its increase usage. The invertebrate model organism, the narrow-clawed crayfish, was selected for its bioindicator role in food webs as planktivorous grazers epibenthic scavengers and good alternative models in ecotoxicology studies with the importance in conservation of freshwater ecosystems. The 96-h LC50 value of permethrin to experimental species was estimated as 0.903 μg/L (95% CI = 0.5042-2.2734 μg/L) with probit analysis method. The sublethal concentration of the permethrin was determined by 1/10 of 96-h LC50 values as 0.09 μg/L. There were two control (negative and acetone) groups in the experiment. The sampling of hemolymph and the tissues (gills, hepatopancreas, and muscle) were done 48 h and 96 h after exposure of the permethrin. The total hemocyte counts significantly increased in the 96-h exposed group of permethrin (p<0.05). Among the hemolymph biochemical parameters, the hemolymph potassium and chloride values increased statistically (p<0.05). Malondialdehyde levels (MDA) of gills and muscle were significantly increased, whereas the MDA level of the hepatopancreas was significantly decreased at the end of the experiment (p<0.05). Hyperplasia in the lamella was recorded in gills, while the degenerations of the hepatopancreas tissues were observed. According to obtained results, permethrin was extremely toxic as acutely to narrow-clawed crayfish and also effected at sublethal concentrations.

Historical distribution of freshwater fishes and the reference conditions concept in a large Mediterranean basin

Abstract The European Water Framework Directive 2000/60/EC (WFD) defines the ecological status of aquatic systems as the deviation between their present biological state and that which would be expected in the absence of any major human disturbance, referred to by the WFD as the ‘reference condition’ (RC). It assumes that their biotic composition should remain balanced and constant over time. This study tested both assumptions against an analysis of the historical distribution of the fish fauna in a large and highly disturbed Mediterranean basin. If fish communities change substantially over time, it will mean that the validity of the RC concept comes into question. Using presence/absence data for historical native fish fauna from the Guadalquivir Basin, distribution changes among sub‐basins were quantified by mapping between the nineteenth century and today. The range of two native species (Anguilla anguilla and Salmo trutta) has changed significantly. In addition, the diadromous species assemblage has almost become locally extinct, with the exception of the eel. Finally, most Guadalquivir sub‐basins (94.7%) have suffered major changes in the composition of their fish communities, either by losing native species or by adding new non‐native species. These results render the definition of any RC unlikely. In Mediterranean areas, the WFD objective of ‘good ecological status’ recovery based on the integrity of aquatic communities is a theoretical rather than a real goal. Nonetheless, the WFD provides an ecological guiding principle that can also be transferred to the conservation of freshwater ecosystems. As an alternative to the RC concept in Mediterranean lotic ecosystems, specific multimetric indices can be used, based on expert criteria, the metrics of which can also relate to the conservation value of water bodies, and not only to their ecological status.

Industrial water conservation by water footprint and sustainable development goals: a review

Application of advanced techniques to ensure the environment sustainability and freshwater ecosystem conservation is a paramount importance. Industrial sector is mostly accused for the increased water pressure with high water consumption rates and increased grey water footprints. Industries must take action toward implementing water conservation strategies to enhance natural water cycle, increase water-use efficiency and address future challenges. The significance of water footprint as a driving force to water conservation is spotlighted with severe water scarcity. “Sustainable Development Goals (SDGs)” proposed by the United Nations are focused on creating a sustainable way of life to reduce the impacts on ecology and achieve economic and social benefits. Water is a central part in sustainable development; thus, all SDGs are interlinked with sustainable water use. The paper reviews incorporating the concept of water footprint to achieve SDGs in relation to industrial water conservation and the future pathways that lead to sustainable water resource management.

The influence of multiple stressors on macroinvertebrate communities and ecosystem attributes in Northern Italy pre-Alpine rivers and streams

Abstract The definition of relationships among the attributes of macroinvertebrate communities and environmental gradients is fundamental to understand ecological dynamics. Testing the response of macroinvertebrate communities and the related metrics to the action of multiple drivers is crucial to provide reliable tools for the management and conservation of freshwater ecosystems. In this study habitat conditions, seasons and physical–chemical water characteristics were evaluated as potential limiting factors for macroinvertebrate communities. 42 sites, along 11 pre-Alpine rivers and streams, were surveyed for macroinvertebrate communities and water chemistry, collecting a total of 387 samples. Hydromorphological characteristics and habitat availability in each sampling site were assessed to describe different features of channel, banks and vegetation that can be relevant for management purposes. Macroinvertebrate community characteristics were summarized by both structural metrics (i.e. density, diversity and taxonomy-based) and ecosystem attributes derived from functional trait analysis. Functional traits are based on morphological and behavioural attributes associated with feeding, modes of attachment, concealment and locomotion, together with voltinism and drift propensity. In this framework, quantitative models have been developed to predict the potential characteristics of macroinvertebrate communities as a function of selected environmental variables. These relationships can be used to predict the effects of river restoration programs on macroinvertebrate diversity and ecosystem processes. The various metrics considered in this study may help to raise a better awareness in the natural functioning of river ecosystems, the selection of effective strategies for the conservation of biological communities, and the evaluation of river restoration success, thus supporting decision-making processes.

Energy development reveals blind spots for ecosystem conservation in the Amazon Basin

Energy development – as manifested by the proliferation of hydroelectric dams and increased oil and gas exploration – is a driver of change in Amazonian ecosystems. However, prevailing approaches to Amazonian ecosystem conservation that focus on terrestrial protected areas and Indigenous territories do not offer sufficient insurance against the risks associated with energy development. Here, we explore three related areas of concern: the exclusion of subsurface rights on Indigenous lands; the absence of frameworks for freshwater ecosystem conservation; and downgrading, downsizing, degazettement (loss of protection), and reclassification of protected areas. We consider these issues from the perspectives of multiple countries across the Amazon Basin, and link them directly to energy development. Finally, we offer suggestions for addressing the challenges of energy development for Amazon ecosystem conservation through existing policies, new approaches, and international collaboration.

Identifying areas of aquatic plant richness in a Mediterranean hotspot to improve the conservation of freshwater ecosystems

Abstract Identifying priority conservation areas is essential for minimizing the loss of biodiversity. Aquatic plants are of particular interest because their contribution to biodiversity is poorly understood and they play a central role in aquatic inland ecosystems. This study thus aimed to identify the areas on the Iberian Peninsula that contain the most aquatic plant species. It also explored the effectiveness of the Natura 2000 network in conserving aquatic plants. To describe macroecological patterns of aquatic plant richness, species distribution models based on bioclimatic factors were generated using maximum entropy modelling. The results were used to identify high‐richness areas of potential conservation interest. Employing gap analysis, the overlap between these areas and the Natura 2000 network was examined to evaluate the effectiveness of the network. The species studied had been recorded in just 34.98% (2172/6209) of the Universal Transverse Mercator (UTM) grid cells examined, meaning that 65.02% of the cells contained no species records. The gap analysis indicated that at least 2.27% of the cells represented areas of high conservation potential. This research underscores the limited effectiveness of the Natura 2000 network in protecting aquatic plants and shows that a high proportion of the aquatic ecosystems studied are subject to severe human pressures. The results of this work provide highly relevant and valuable information on the less‐studied regions of the Iberian Peninsula. Overall, the findings presented here should greatly inform the development of more objective strategies for conserving zones with a high diversity of aquatic plants. The information acquired should be used in future efforts to identify new priority conservation areas and assess those already in place.

MENGENAL IKAN-IKAN DANAU SENTANI

Lake Sentani is the biggest lowland lake in Papua and the biggest freshwater fish source in Jayapura. The lake has highest endemism and one of freshwater ecosystem conservation priorities in Papua. Lake organisms consist of water plants, mollusks, crustacea and fish. In Lake Sentani, there are 19 species of fish including endemic, native and anadromous and introduced species. This program aims to deliver knowledge on fish species of Lake Sentani and fish species grouping for elementary school students, grade IV to VI of SD Negeri 5 Puay, Puay Village, East Sentani District, Jayapura. Methods used were seminar, training and practice of fish species grouping, drawing a fish and writing its story. Moreover, pre test and post test consist of questions about Lake Sentani fish and its grouping was deliver to measure the level of knowledge of the students before and after the program. Level of knowledge of students on fish of Lake Sentani was evaluated based on the results of pre test and post test. Student knowledge on Lake Sentani fish species were increasing which show by pre test and post test results. Twelve out of 13 (92%) students showed their post test results were increasing and only one student’s test result was decreasing. Eventhough there are more students with good post test result than those who do not, the level of knowledge on Lake Sentani’s fish and its grouping is not fairly distributed among the students. It is shown by the fact that there are 62% or 8 students that doing poorly on this test. Therefore, various programmes with various teaching methods for students should be desigend to increase knowledge of students on fish species and its grouping in Lake Sentani. Keywords: fish, fish grouping, Lake Sentani, Puay, students

Moving beyond fitting fish into equations: Progressing the fish passage debate in the Anthropocene

Abstract Realization of the importance of fish passage for migratory species has led to the development of innovative and creative solutions (‘fishways’) to mitigate the effects of artificial barriers in freshwater systems in the last few decades. In many instances, however, the first move has been to attempt to engineer a solution to the problem, thus attempting to ‘fit fish into an equation’. These fishways are often derived from designs targeting salmonids in the Northern Hemisphere. They are rarely adequate, even for these strong‐swimming fish, and certainly appear to be unsuitable for most other species, not least for those of tropical regions. Fishway design criteria do not adequately account for natural variation among individuals, populations and species. Moreover, engineered solutions cannot reinstate the natural habitat and geomorphological properties of the river, objectives that have been largely ignored. This article discusses the most prominent issues with the current management and conservation of freshwater ecosystems as it pertains to fish passage. It is not intended as a review on fish passage, but rather a perspective on the issues related to fishways, as seen by practitioners.

Improved genetic markers for monitoring recruitment dynamics in the endangered Mary River cod (Maccullochella mariensis)

The Mary River cod (Maccullochella mariensis) is a large predatory freshwater fish identified as a potential flagship for freshwater ecosystem conservation in Australia. The species is endemic to the Mary River catchment in eastern Australia, and is listed as Endangered. Previous conservation genetic assessment of Mary River cod was based on a small set of microsatellite loci developed for congeneric Maccullochella species. Here we develop a novel set of 15 microsatellite loci specific to M. mariensis, and demonstrate that these markers exhibit higher variability than those used previously. Mean number of alleles per locus was 4 and mean expected heterozygosity was 0.57. We genotyped 35 Mary River cod larvae belonging to a single cohort using the 15 novel loci and eight previously used loci, and found 10 full‐sib family groups along with clear genetic differentiation between individuals collected from the two sub‐catchments – Tinana Creek and Mary River. Microsatellites presented here will be useful for cost‐effective monitoring of genetic diversity and recruitment dynamics in this endangered fish species.

Integrating within-catchment and interbasin connectivity in riverine and nonriverine freshwater conservation planning in the North China Plain

Freshwater ecosystems encompass all inland water bodies, in which riverine and nonriverine freshwaters are linked through hydrological connectivity within a catchment. However, riverine and nonriverine freshwaters have often been assessed separately and their interdependence and connection has not been considered appropriately in prevailing freshwater conservation planning. To address the representation and persistence of freshwater ecosystems in conservation assessment, we integrated riverine and nonriverine freshwater wetlands as broad-scale conservation surrogates and incorporated longitudinal, lateral and vertical connectivity rules in a conservation planning for the freshwater wetlands in the North China Plain (NCP). We also considered interbasin connectivity by incorporating conservation features of key transferring nodes of the South-to-North Water Diversion Project (SNWD) in the NCP to safeguard their unique ecosystem services of regulating interbasin freshwater. Three scenarios (i.e., 2D, 3D and interbasin scenario) were developed by incorporating different multiple conservation targets, and their spatial priorities and cost-efficiency in freshwater conservation were compared. We applied systematic conservation framework and modified Marxan to accommodate these multidirectional and interbasin connectivity targets in our freshwater conservation assessment. The results indicated that the existing conservation system covered approximately 20% of the freshwater wetlands in the NCP, and there were still considerable conservation gaps that need to be filled. The optimal scenarios could substantially improve the representation, complementarity and persistence for the conservation of freshwater ecosystems, but would not significantly increased overall costs. The framework developed by our research has the potential to facilitate further application of systematic methods in freshwater conservation and rehabilitation planning at multiple scales.

Landscape variables influence taxonomic and trait composition of insect assemblages in Neotropical savanna streams

Summary Stream invertebrate assemblages are structured by environmental factors acting at multiple spatial scales. Identifying the spatial scale that most influences the species–environment relationships is a major goal of community ecology. We evaluated the importance of catchment and site scales and associated environmental variables in shaping Ephemeroptera, Plecoptera and Trichoptera (EPT) assemblages in Neotropical savanna headwater streams. Sampling sites were associated with 20 catchment‐scale variables that depicted land cover and land use as well as natural geophysical variables such as altitude and climate. Site‐scale habitat was characterised by 55 variables that described habitat hydromorphology, substrate, flow, canopy, in‐stream cover and water quality. EPT traits were assessed using 28 categories of 7 biological traits, which represented the best available current knowledge for EPT in Neotropical savanna streams. We analysed the relationships between the catchment‐ and site‐scale habitat variables and the taxonomic and trait composition of insect assemblages using 1,760 samples collected in 160 stream sites. Catchment‐ and site‐scale variables both explained significant variation in EPT taxon and trait composition. Substrate, habitat hydromorphology and land use most influenced variation in taxonomic composition, whereas trait composition was mainly affected by land use. Catchment geographic position explained less assemblage variation. To our knowledge, this study is the first assessment of the impact of catchment‐ and site‐scale variables on the trait and taxon composition of stream insect assemblages in Neotropical savanna streams. It highlights the need for better regional biological knowledge of invertebrates to generate more general trait‐based approaches in freshwater ecosystem conservation.

How Does Environmental Variation Affect the Distribution of Dragonfly Larvae (Odonata) in the Amazon-Cerrado Transition Zone in Central Brazil?

This study investigated the effects of environmental variation on assemblages of dragonfly larvae (Odonata). We hypothesize that there is a significant correlation between species richness, species composition, and abundance of Odonata individuals, and habitat integrity and abiotic variables. To test this hypothesis, we sampled odonate larvae at 12 streams in the Suiá-Miçú River basin in Mato Grosso, Brazil, during three different periods of the year. Local physical and chemical variables (temperature, pH, turbidity, electrical conductivity (EC), dissolved oxygen (DO), total dissolved solids (TDS), and oxidation reduction potential (ORP)) were measured at each site using a multi-parameter probe, and integrity was assessed using the Habitat Integrity Index (HII). The variation in richness, abundance, and composition of Odonata species was related to the environmental variables analyzed, primarily by the abiotic factors pH, electrical conductivity, dissolved oxygen, total dissolved solids, and oxidation reduction potential. Our hypothesis was corroborated for the suborder Anisoptera, which showed a significant relationship with these variables, whereas Zygoptera was only related to pH. Our results show the importance of physical and chemical conditions in ecological studies using Odonata larvae as tools for the management and conservation of freshwater ecosystems.