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1.
  1. Limnological aspects of Amazon floodplain lakes are examined in the context of aquatic conservation.
  2. A prerequisite to detecting and evaluating changes that could threaten the ecological health and organisms in floodplain lakes is understanding variation under present conditions. Based on one of the few studies with regular measurements over 2 years, chlorophyll, total phosphorus, dissolved oxygen, transparency, and total suspended solids in Lake Janauacá indicate that the lake is naturally quite variable with a mesotrophic to eutrophic status.
  3. Direct threats to ecological health of floodplain lakes include mining operations that can increase turbidity and trace metals and reduce nutritional quality of sediments. Mercury contamination and methylation leads to bioaccumulation in aquatic organisms.
  4. Deforestation in uplands increases nitrogen and phosphorus inputs to floodplain lakes and can alter trophic status. Deforestation in floodable forests alters the habitat and food of the fish that inhabit these forests.
  5. Cumulative limnological responses as catchments are altered by urban, agricultural, and industrial developments, and as inundation is altered by changes in climate and construction of dams, have major implications for the ecology of floodplain lakes.
  6. To improve understanding and management of threats to the conservation of aquatic Amazon biota and ecosystems requires considerably expanded and coordinated research and community-based management that includes the spectrum of floodplain lakes throughout the basin.
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2.
  1. Aquatic mammals worldwide are highly threatened in freshwater ecosystems where they are affected by direct human activities (e.g. hunting) as well as indirect human alteration of freshwater ecosystems (e.g. dams, mining activity). Although aquatic mammals of the Amazon Basin are experiencing many growing threats, little is known about the escalating impacts on them, current limitations in protection mechanisms, and possible strategies to ensure their conservation. This study synthesizes the available information on Amazonian aquatic mammals, including the ecological characteristics of these species, key threats, population status and conservation prospects.
  2. Amazonian aquatic mammals comprise seven species – Inia geoffrensis, Inia boliviensis, Inia araguaiaensis, Sotalia fluviatilis, Trichechus inunguis, Pteronura brasiliensis and Lontra longicaudis – which are characterized by low reproductive rates and keystone ecosystem roles. These species are endangered mainly by biological resource use, natural ecosystem modifications, energy production and mining, and climate change. Although information is sparse, there is evidence that these threats are inducing population declines of Inia spp., and hindering the recovery of populations of P. brasiliensis.
  3. Protection mechanisms for these species mostly include national and international laws and agreements, legislation governing environmental licensing and protected areas. Each of these protection mechanisms, however, has limited capacity to protect Amazonian aquatic mammals, largely because they are poorly enforced, lack transnational coordination or require population trend data that do not exist.
  4. Reversing the current state of affairs for Amazonian aquatic mammals requires an integrated research and policy approach that, at a minimum, substantially increases the present capacity to monitor their population responses to human impacts, establishes effective enforcement of existing legislation and prevents further impacts from hydropower development. To implement such an approach, information on the ecology of these species is necessary to create public and scientific awareness.
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3.
  1. The Amazon River basin contains a vast diversity of lotic habitats and accompanying hydrological regimes. Further understanding the spatial distribution of flow regimes across the Amazon can be useful for recognizing riverine ecohydrological processes and informing river management and conservation, especially in areas with limited or inconsistent streamflow monitoring.
  2. This study compares four inductive approaches for classifying streamflow regimes across the Amazon using an unprecedented compilation of streamflow records from Bolivia, Brazil, Colombia, Ecuador, and Peru.
  3. Inductive classification schemes use attributes of streamflow data to categorize river reaches into similar classes, which then may be generalized to understand streamflow behaviour at the basin scale. In this study, classification was accomplished through hierarchical clustering of 67 flow metrics calculated using indicators of hydrologic alteration (IHA) and daily streamflow data from median annual hydrographs (MAHs) for 404 stations (representing >7,000 station-years) across five Amazonian countries.
  4. Classification was performed using both flow magnitude-inclusive and flow magnitude-independent datasets. For flow magnitude-independent methods, optimal solutions included six or seven primary hydrological classes for IHA and MAH datasets; for approaches that retained magnitude, variance was sufficiently large to prevent convergence to a specific number of classes.
  5. Across methods, class membership was strongly associated with the timing, frequency, and rate of change of flow, and spatially coherent clusters were associated with seasonal, elevational, and stream-order gradients. These results highlight the diversity of flow regimes across the Amazon and provide a framework for studying relationships between hydrological regimes and ecological responses in the context of changing climate, land use, and human-induced hydrological alteration.
  6. The methodology applied provides a data-driven approach for classifying flow regimes based on observed data. When coupled with ecological knowledge and expertise, these classifications can be used to develop ecohydrologically informed and management-relevant conservation practices.
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4.
  1. The Amazon Basin is being degraded at unprecedented rates, yet conservation efforts have implemented protected areas to curb deforestation, leaving freshwater ecosystems vulnerable to degradation. Amazon freshwater ecosystems are largely unprotected because a terrestrial bias has limited the ability of science to affect policy.
  2. Overcoming this bias requires increasing exchange of information among stakeholders across the basin to raise awareness of threats to Amazon freshwater ecosystems and promote discussions and access to conservation solutions. To help address this need, this Special Issue collates 15 synthetic articles that advance knowledge and identify conservation solutions.
  3. Three articles highlight the importance of considering the hydrological and limnological processes that control the integrity of these freshwater ecosystems and offer new insights on how to extrapolate them across the basin.
  4. Three articles on crocodilians, aquatic mammals, and migratory fishes document threats and knowledge gaps, and identify the missing role of governments as an impediment to conservation of their populations.
  5. Three articles evaluate the multi-faceted effects of hydropower dams on fish, birds, and floodplain trees. They reinforce perceptions that dams are key environmental threats and offer guidance for improving protocols for dam site selection and impact assessment.
  6. Three articles assessing the effectiveness of protected areas to safeguard fish and aquatic invertebrates show there is an urgent need to redesign the Amazon protected area network to adequately protect freshwater biota.
  7. Three forward-looking articles show that: (i) conservation initiatives by local communities are ‘bright spots’ for freshwater conservation; (ii) microchemistry analyses of the ear bones of fishes could boost the knowledge base needed to conserve them; and (iii) strengthening the Amazon conservation framework requires a reversal of Brazil's current governmental priorities, remobilization of stakeholders, investments in capacity building, and expanding protections to terrestrial and freshwater ecosystems.
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5.
  1. Freshwater environments host roughly half of the world’s fish diversity, much of which is concentrated in large, tropical river systems such as the Amazon. Fishes are critical to ecosystem functioning in the Amazon River basin but face increasing human threats. The basic biology of these species, and particularly migratory behaviour, remains poorly studied, in part owing to the difficulty associated with conducting tagging studies in remote tropical regions.
  2. Otolith microchemistry can circumvent logistical issues and is an increasingly important tool for studying fish life histories. However, this approach is still new in the Amazon, and its potential and limitations to inform fish conservation strategies remain unclear.
  3. Here, otolith microchemistry studies in the Amazon are reviewed, highlighting current possibilities, and several key factors that limit its use as a conservation tool in the Amazon are discussed. These include the dearth of spatiotemporal elemental data, poor understanding of environment–fish–otolith pathways, and insufficient funding, facilities, and equipment.
  4. A research initiative is proposed to harness the potential of this technique to support conservation in the Amazon. Key aspects of the proposal include recommendations for internal and external funding, which are critical to acquiring and maintaining technical staff, cutting-edge equipment, and facilities, as well as fostering regular scientific meetings and working groups. Meetings can facilitate a systematic approach to investigating environment–otolith pathways, broadening the chemical baseline for most Amazonian tributaries, and exploring potential valuable elements.
  5. These outcomes are urgently needed to conserve biodiversity and ecosystem functioning in the Amazon, especially given threats such as widespread hydroelectric damming. The initiative proposed here could make otolith microchemistry an important, cost-effective tool to inform and foster conservation in the Amazon, and act as a template for other imperilled tropical river basins, such as the Mekong and the Congo.
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6.

7.
  1. Human translocations of non-native aquatic species are a global conservation challenge. Aquarists and anglers are two hobbyist groups whose practices are particularly likely to translocate non-native aquatic species, especially fish.
  2. This article aims to stipulate a change of perspective among these hobbyists, who – by acting simultaneously as anglers and aquarists – establish novel pathways for non-native fish.
  3. This study showed that: (i) 51 of 226 respondents to a questionnaire act simultaneously as anglers and aquarists; (ii) 53 of 237 non-native fish species in the European Union are used for both angling and aquarium hobbies; and (iii) hobbyists write online reports on the catch and exchange of a particularly invasive fish, the round goby (Neogobius melanostomus).
  4. This combination of knowledge on how hobbyists use non-native fish and the ecological impacts of round goby demonstrates how the impact of an invasive species can be influenced by the combined behaviours of anglers and aquarists.
  5. We suggest that future research in aquatic conservation should move beyond considering the commercial aquarium trade and angling as separate pathways for translocating non-native fish, and instead consider these hobbyist groups as interconnected.
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8.
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9.
  1. Free-flowing tributaries are important for the maintenance of fish diversity in dammed systems. In relation to the reproduction of fish species, the role of a free-flowing tributary was evaluated and compared with that of a dammed tributary downstream of large dams in the Madeira River, one of the main tributaries of the Amazon River.
  2. Two hypotheses were tested: (i) the densities of the ichthyoplankton differ between the dammed and the free-flowing tributaries; and (ii) the free-flowing tributary contributes a greater diversity of fish larvae species to the assemblage structure of the main stem than the dammed tributary.
  3. Fish eggs and larvae were sampled at five sites: one in each tributary (Jamari – dammed – and Machado – free-flowing) and three in the main stem (Madeira River), upstream and downstream from the mouth of each tributary.
  4. Fitted Bayesian models showed that the densities both of eggs and larvae were more than twice as high in the free-flowing tributary than in the dammed tributary. The results also indicated that the free-flowing tributary makes a major contribution to the fish assemblage structure of the Madeira River, whereas the dammed tributary does not have a significant influence on the main stem assemblage structure.
  5. The results demonstrate the importance of conservation and maintenance not only of the Machado River but also of other free-flowing tributaries in dammed basins, especially those basins with high biodiversity, such as the Amazon. Moreover, this study helps inform the decision-making process regarding the location of new dams, which is critical in fish diversity conservation.
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10.
  1. Wetlands in arid regions are characterized by their great heterogeneity, often including endemic species that contribute to regional aquatic biodiversity. In the Patagonian steppe, most lakes are naturally fishless and sustain a rich aquatic biodiversity, including endemics; however, many of these lakes have been stocked with Oncorhynchus mykiss (rainbow trout) during recent decades. The introduction of predatory fish into aquatic ecosystems naturally devoid of these organisms can produce profound alterations in the structure of the original communities and in the configuration of their biotic assemblages.
  2. Aquatic invertebrates play important roles in both the structure and functioning of freshwater ecosystems, including their contribution to global biodiversity and their cascading effects across ecosystem boundaries.
  3. The aim of this study was to assess the effect of introduced non-native fish on the pleustonic macroinvertebrate assemblage. Samples were taken from 10 shallow Patagonian lakes (five fishless and five stocked with fish) in two consecutive warm periods.
  4. Lakes with fish had higher conductivity and phosphate values. Higher inter-annual differences were also observed in lakes with fish for phytoplanktonic chlorophyll a, nitrate, phosphate, conductivity, and water temperature.
  5. The community structure (relative abundance of different taxa, species composition, and diversity index) was affected by the presence of rainbow trout, with the differences mainly driven by the relative abundance of Ostracoda, Hyalella, Chironomidae, and Haliplus species.
  6. This approach can be used to assess the required conservation actions in shallow Patagonian steppe lakes, which have been listed as priority areas for waterbird conservation. Specifically, this study provides a baseline for monitoring future trends of the macroinvertebrate communities and for evaluating conservation and management efforts over time.
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11.
  1. Case studies of Marine Protected Area (MPA) upscaling were solicited from participants of a workshop at the International Marine Protected Areas Conference held in Autumn 2013 in Marseille.
  2. One such case study was Solandt, Jones, Duval‐Diop, Kleiven, and Frangoudes (2014; Governance challenges in scaling up from individual MPAs to MPA networks. Aquatic Conservation: Marine and Freshwater Ecosystems, 24, 145–152) which illustrated the role of science, non‐governmental organizations, government and local regulators in applying systemic management measures for local MPAs based on risk, highlighting the importance of balancing top‐down and bottom‐up drivers.
  3. Here we follow up on the UK example, illustrating the incentives and actors involved in developing centralized and subsequent fisheries management measures in UK waters. Forty local laws were created to protect features in 143 inshore MPAs between 2013 and 2019.
  4. We illustrate best practice in delivering management, focusing on multiple practitioner involvement in a single MPA and the monitoring put in place after trawling and dredging were banned.
  5. We reflect on how the governance mechanisms in place in English inshore waters can be used as a template to allow for progressive MPA management in other coastal states.
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12.
  1. The history of conservation of the Amazon can be viewed as a war involving many battles with interests in agribusiness on one side and in biodiversity conservation and sustainability on the other side. Trends in large-scale deforestation in the 1970s spurred a series of policies, stakeholder alliances and international and grass-roots movements, which decades later led to the establishment of protected areas and interventions in soy and beef supply chains of agribusiness. Together, these advances epitomized a conservation framework for the Amazon, which at one point nearly curbed deforestation in the Brazilian Amazon, although it included very few protections for freshwater ecosystems.
  2. While those conservation advances were taking place, however, a series of policy changes started to undermine them through expansions in deforestation, river regulation and mining activities. The election of Brazil's President Jair Bolsonaro in 2019 then hit the Amazon conservation framework much like a tsunami of policy setbacks and the re-establishment of the economic policies that sparked the Amazon war in the past.
  3. The current trajectory is one of large-scale degradation of Amazonian ecosystems and biodiversity with consequent impacts on local people. Because freshwater ecosystems are highly sensitive to human activities on water and on land, these growing impacts are particularly large.
  4. It is too early to know, but four decades of institutional and policy developments to conserve the Brazilian Amazon may soon be pushed past the point from which they will be able to recover. Four conditions will be pivotal to allowing the Amazon conservation framework to recoup: (a) the end of Bolsonaro’s mandate in 2022 or earlier; (b) remobilization of stakeholders; (c) investments in environmental research, policy and multiple collaborations; and (d) moving conservation beyond terrestrial landscapes to also encompass freshwater ecosystems and their people.
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13.
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14.
  1. Translating scientific evidence into practical actions is a primary goal of scientists working to inform evidence‐based policy and decision‐making, but how can authors best facilitate new conservation interventions following publication of their research?
  2. This case study used two articles in Aquatic Conservation: Marine and Freshwater Ecosystems (AQC) to examine the mechanisms and barriers to translating published aquatic science into social, ecological and policy interventions for the conservation of threatened Murray crayfish (Euastacus armatus).
  3. These articles revealed how steep declines in Murray crayfish abundance arose from the loss of in‐stream and riparian habitats preferred by crayfish, and demonstrated the social reasons for conserving Murray crayfish to protect the wellbeing of a diversity of people (e.g. Traditional Owners, landholders, ecotourism operators).
  4. Following publication of these articles in AQC the authors used multi‐modal communication (e.g. written briefs, personal discussions, seminars, magazine articles, media broadcasts) to translate their findings to stakeholders and the general public.
  5. Analysis of relevant documents (e.g. management plans, public information leaflets) and stakeholder interviews uncovered a range of interventions arising from the two AQC articles. Social interventions (e.g. new public signage, ecotourism briefings) were the quickest to occur after publication (1–2 years). Although some changes in management were apparent (e.g. revised Murray crayfish action plans, monitoring programmes), systemic barriers (e.g. policy/funding timeframes) have prevented some ecological and policy interventions from being realized.
  6. Diverse communication strategies can help rapidly translate published science into new conservation actions by giving stakeholders the right evidence in the right way to inform their particular practice. Open‐access summaries that explain findings within readily shareable media (e.g. graphical/video abstracts) can be particularly effective in raising early awareness. Some types of intervention, however, may require a long‐term perspective and assistance from boundary‐spanning knowledge brokers with an aptitude for evidence‐based policy development.
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15.
  1. This article introduces a special issue of Aquatic Conservation: Marine and Freshwater Ecosystems (AQC) whose contributions demonstrate examples of the practical impact of the authors' previous AQC articles on the conservation of aquatic ecosystems.
  2. The submitting authors of all articles published in AQC since 2009 were invited to express their interest in writing an article for the special issue. The 20 articles selected for publication discuss 33 AQC articles published from 2004 to 2019, spanning a wide range of geographical locations, habitat types, species groups, and impacts on aquatic conservation.
  3. The two impacts reported most frequently are ‘Undertaking practical management of habitats and species’ and ‘Establishing partnerships’, closely followed by ‘Restoring habitats/reintroducing or translocating species’. Many authors demonstrate the importance of their articles in raising awareness across an extensive range of organizations.
  4. Some impacts occur soon after publication (e.g. introduction of conservation guidelines), whereas others (e.g. influencing policy) take far longer. Authors report a wide range of methods for disseminating research results appropriate for different audiences, such as technical handbooks, seminars, magazine articles, media broadcasts, and field workshops.
  5. To assess whether ‘conventional’ measures of impact match authors' perceptions, three metrics were calculated for the 33 AQC articles discussed in this issue: the number of citations, the number of downloads, and the Altmetric Attention Score. These metrics were not significantly higher for the 33 articles than the corresponding median metrics of the articles in the issues in which the 33 were published.
  6. The goal of AQC is to continue to encourage scientists to recognize and promote the application of their research to practical conservation and management. Given the growing threats to aquatic ecosystems, much remains to be done to make this process even more effective.
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16.
  • 1. The vegetation of disused and occasionally used navigation canals with acknowledged botanical conservation value was compared with that of major land‐drainage channels with potential conservation interest.
  • 2. Aquatic plant taxa and their abundance were recorded in 500‐m lengths of watercourses in East Yorkshire, north‐east England.
  • 3. There was substantial overlap between canals and drains in the aquatic plant species recorded (42 out of 66 taxa were found in both canals and drains) and ordination analysis (DECORANA) showed that there were not two distinct vegetation types: one for canals and one for drains.
  • 4. The aquatic plants recorded in both canals and drains probably largely originated from an eighteenth‐ and nineteenth‐century pre‐drainage marshland flora that has since been lost.
  • 5. The conservation value of the aquatic vegetation at canal sites (assessed as diversity, rarity and naturalness) was not significantly greater than at the drain sites.
  • 6. The canals are potentially threatened by restoration of navigation or increase in boat usage; a simplistic interpretation of the results is that potential losses in the conservation value of canals would be substituted by the flora of the drains.
  • 7. A more measured interpretation, however, is that the canals and drains should be regarded as parallel conservation resources. This is because some aquatic plant taxa with limited distribution at local, regional or national level were found only in canals while others were found only in drains.
  • 8. The results emphasize that evaluation of the botanical conservation value of artificial watercourses should include drains as well as canals; disused and lightly used navigation canals are widely recognized as of high conservation value whereas drains, being utilitarian landscape features, are more likely to be overlooked.
Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

17.

18.
  1. The Amazon basin has been subjected to extreme climatic events and according to climate change projections this hydrosystem could face changes in the natural dynamic of flood cycles that support the feeding and reproduction of many fish species, threatening aquatic biodiversity.
  2. Protected areas (PAs) are the main tools used to safeguard the biodiversity in the long term; however, they are fixed areas that could be subject to climate change, questioning their future efficiency in protecting biodiversity.
  3. The Amazon basin currently benefits from a relatively high level of protection as 52% of its catchment area is under the form of true PAs or indigenous lands. However, the capacity of these PAs to protect freshwater biodiversity remains unclear as they have generally been assessed with little regard to freshwater ecosystems and their hydrological connectivity. Here, the aim was to evaluate the effectiveness of PAs in representing the Amazon fish fauna under current and future climatic conditions.
  4. A macroecological approach was used to estimate the minimum size of the geographical range needed by each species to achieve long-term persistence, by a combined function of range size and body size, two ecological traits known to influence species extinction risk.
  5. In future the Amazon basin could risk losing 2% of its freshwater fish fauna owing to unsuitable climatic conditions, with a further 34% adversely affected. The present Amazon network of PAs will cover the minimum required range for species persistence for more than 60% of the freshwater fish species analysed under the future climate scenario. However, more than 25% of the future susceptible species are currently concentrated in large tributaries and in the central-lower Amazon floodplain where few PAs occur, highlighting the lack of appropriate conservation actions for these specific water bodies.
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19.
  1. In 1949, Aldo Leopold formalized the concept of the ‘land ethic’, in what emerged as a foundational and transformational way of thinking about natural resource management, biodiversity conservation, and stewardship in terrestrial systems. Yet, the land ethic has inherent linkages to aquatic ecosystems; Leopold himself conducted research on rivers and lakes, and freshwater ecosystems figured widely in his writing.
  2. We reflect on the land ethic and other aspects of Leopold's scholarship to identify key messages that provide insight into the stewardship and management of freshwater ecosystems around the globe. We also frame what we call the ‘freshwater ethic’ around Leopold's legacy. Although Leopold could not have envisaged the stressors affecting modern aquatic ecosystems, his core principles remain salient. These apply not only to ecosystem protection, but also to the ethics of modern conservation economics, sustainability, and the protection of natural capital, in which lakes, rivers, and wetlands now figure prominently.
  3. We identify key ‘Aldo-inspired’ recommendations for protecting and restoring freshwater ecosystems in the Anthropocene that emanate directly from his writings (e.g. adopt an ecosystem approach, identify win–win–win scenarios, recognize the irreplaceability of wild waters, and strive for freshwater optimism).
  4. In an epoch where links between people and nature are becoming more explicit in environmental management, policy, and governance, we suggest that Aldo Leopold's work illustrates how inspirational, seminal thinkers have offered leadership in this domain. We contend that today there is still much that can be learned from Leopold, especially by the next generation of environmental practitioners, to ensure the effective stewardship of our aquatic ecosystems.
  5. We submit that the adoption of a freshwater ethic in parallel with Leopold's land ethic will enhance the stewardship of the world's increasingly threatened fresh waters by raising the profile of the plight of fresh waters and identifying enduring actions that, if embraced, will help conserve and restore biodiversity.
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