Cross-continental evaluation of landscape-scale drivers and their impacts to fluvial fishes: Understanding frequency and severity to improve fish conservation in Europe and the United States

Fluvial fishes are threatened globally from intensive human landscape stressors degrading aquatic ecosystems. However, impacts vary regionally, as stressors and natural environmental factors differ between ecoregions and continents. To date, a comparison of fish responses to landscape stressors over continents is lacking, limiting understanding of consistency of impacts and hampering efficiencies in conserving fishes over large regions. This study addresses these shortcomings through a novel, integrative assessment of fluvial fishes throughout Europe and the conterminous United States. Using large-scale datasets, including information on fish assemblages from more than 30,000 locations on both continents, we identified threshold responses of fishes summarized by functional traits to landscape stressors including agriculture, pasture, urban area, road crossings, and human population density. After summarizing stressors by catchment unit (local and network) and constraining analyses by stream size (creeks vs. rivers), we analyzed stressor frequency (number of significant thresholds) and stressor severity (value of identified thresholds) within ecoregions across Europe and the United States. We document hundreds of responses of fish metrics to multi-scale stressors in ecoregions across two continents, providing rich findings to aid in understanding and comparing threats to fishes across the study regions. Collectively, we found that lithophilic species and, as expected, intolerant species are most sensitive to stressors in both continents, while migratory and rheophilic species are similarly strongly affected in the United States. Also, urban land use and human population density were most frequently associated with declines in fish assemblages, underscoring the pervasiveness of these stressors in both continents. This study offers an unprecedented comparison of landscape stressor effects on fluvial fishes in a consistent and comparable manner, supporting conservation of freshwater habitats in both continents and worldwide

An assessment of the state of conservation planning in Europe

Expanding and managing current habitat and species protection measures is at the heart of the European biodiversity strategy. A structured approach is needed to gain insights into such issues is systematic conservation planning, which uses techniques from decision theory to identify places and actions that contribute most effectively to policy objectives given a set of constraints. Yet culturally and historically determined European landscapes make the implementation of any conservation plans challenging, requiring an analysis of synergies and trade-offs before implementation. In this work, we review the scientific literature for evidence of previous conservation planning approaches, highlighting recent advances and success stories. We find that the conceptual characteristics of European conservation planning studies likely reduced their potential in contributing to better-informed decisions. We outline pathways towards improving the uptake of decision theory and multi-criteria conservation planning at various scales, particularly highlighting the need for (a) open data and intuitive tools, (b) the integration of biodiversity-focused conservation planning with multiple objectives, (c) accounting of dynamic ecological processes and functions, and (d) better facilitation of entry-points and co-design practices of conservation planning scenarios with stakeholders. By adopting and improving these practices, European conservation planning might become more actionable and adaptable towards implementable policy outcomes

Reviewed literature on the state of conservation planning in Europe

Literature review of European conservation planning studies The data table uploaded here contains reviewed literature as part of the manuscript "An assessment of the state of conservation planning in Europe” by Jung et al. that is currently in Review. In this work we reviewed all available scientific literature broadly dealing with conservation planning in various facets and across realms (terrestrial, freshwater, marine). The database provided here thus provides a comprehensive starting point of all scientific conservation planning studies conducted in Europe up until mid 2023. The dataset is derived from a Scopus literature query conducted on the 23th of September 2022, which resulted in an initial 1459 studies which were further refined and supplemented by evidence known to the authors. --- # Description of table columns: "ID" = Numeric Identifier of the study "Extent" = Scale the study was conducted, from local, regional, national to European wide "Region" = The broad region with regards to European country "Locality" = Additional detail on the locality of the study if easily available "Realm" = Which realm does the study cover (e.g. Terrestrial, Marine, ...) "Ecosystem.specificity" = Was the study conducted only for specific ecosystems (e.g. Forests)? "Period" = Over which period was the study conducted (Present only, future conditions, both) "Planning.purpose" = What was the purpose of the study? "Policy.relevance" = Specific policy directives or legal documents referred to in the study introduction. "Method" = Which method was used for the planning purpose (i.e., Zonation, Marxan, ...) "Biodiversity.type; = What type of Biodiversity data was included in the study? "Number.of.features" = How many number of features? "Multiple.objectives.or.constraints" = Did the study somehow account for multiple objectives or constraints? "Connectivity" = Was connectivity somehow considered and if so, how? "Costs" = Were socio-economic costs somehow considered? "Stakeholder.involvement" = Were stakeholders involved in the planning exercise at any point? "Authors" = Authors of the study "Title" = The title of the study "Year" = The year it was published "Journal" = The scientific journal were it was published "DOI" = A Digital Object identifier link (can sometimes be missing) "Link" = A link to the journal website (can be missing) "Author.Keywords" = Keywords by the authors given to the study (can be missing) "Index.Keywords" = Keywords captured by SCOPUS for the study (can be missing) "Document.Type" = Type of article "Source" = Derived from SCOPUS or manually added through a snowballing approach? "cite_scientific_May2023" = How often cited in the scientific literature by May 2023? "cite_policy_May2023" = How often cited in policy literatue by May 2023

Livrable 5.4 : Rapport sur la comparaison de la sensibilité des métriques poisson à des stress multiples dans les rivières, les lacs et les eaux de transition

Aquatic ecosystems facing multiple stressors lead to challenging conditions for their management, as stressors can have additive, but also interactive effects on organisms, populations and communities. Accounting for these interactions is important in the assessment of the stressor’s impacts and to implement good restoration measures. Using a comparable modelling approach and large environmental and fish databases, the combined effect of water quality problems and hydrological stressors were assessed, based on characteristics of fish assemblages observed in rivers, lakes, reservoirs and estuaries of Europe. The effects of nonnative species in interaction with eutrophication and alteration of hydromorphology were also tested for fish assemblages of natural lakes and reservoirs. We show that for all the water body types, water quality problems are a major threat that impacts fish assemblages. Similarly, alteration of the hydro-morphology explains a large part of the composition of river and estuarine fish assemblages. Conversely, we fail to demonstrate an effect of this stressor on the fish community of lakes and reservoirs, as sufficient data are not available yet. However, in these standing waters the introduction of non-native species can explain the variability of some characteristics of fish assemblages. In a second step, we analysed the interactive effect of various stressors. Without interaction, the effect of two stressors on a fish assemblage characteristic corresponds to the sum of the individual effects. This additive effect was compared with the effects really observed in the assemblages to determine the type of interaction. The comparison was done for each fish assemblage characteristic impacted by stressors in each water body type. A large variability of multi-stressor impacts was observed, leading to higher or lower effects than expected in absence of interactions. These results suggest to consider all potential stressors and interactions in the development of fishbased tools dedicated to ecological status assessment or restoration monitoring whatever the water body type is