Christian Wolter

Bio: Christian Wolter is an academic researcher from Leibniz Association. The author has contributed to research in topics: Rutilus & Habitat. The author has an hindex of 39, co-authored 141 publications receiving 5288 citations. Previous affiliations of Christian Wolter include Leibniz Institute for Neurobiology.

Light pollution as a biodiversity threat.

Abstract: In a recent TREE article, Sutherland and colleagues [1] used horizon scanning to identify fifteen emerging issues in biodiversity conservation. They discussed both threats and opportunities for a broad range of issues, including invasive species, synthetic meat, nanosilver and microplastic pollution. We recognize that the article was not intended to be comprehensive, but feel they overlooked an emerging problem of great importance and urgency, namely that of light pollution. Although the widespread use of artificial light at night has enhanced the quality of human life and is positively associated with security, wealth and modernity, the rapid global increase of artificial light has fundamentally transformed nightscapes over the past six decades, both in quantity (6% increase per year, range: 0–20%) and quality (i.e.

The Dark Side of Light: A Transdisciplinary Research Agenda for Light Pollution Policy

Abstract: Although the invention and widespread use of artificial light is clearly one of the most important human technological advances, the transformation of nightscapes is increasingly recognized as having adverse effects. Night lighting may have serious physiological consequences for humans, ecological and evolutionary implications for animal and plant populations, and may reshape entire ecosystems. However, knowledge on the adverse effects of light pollution is vague. In response to climate change and energy shortages, many countries, regions, and communities are developing new lighting programs and concepts with a strong focus on energy efficiency and greenhouse gas emissions. Given the dramatic increase in artificial light at night (0 - 20% per year, depending on geographic region), we see an urgent need for light pollution policies that go beyond energy efficiency to include human well-being, the structure and functioning of ecosystems, and inter-related socioeconomic consequences. Such a policy shift will require a sound transdisciplinary understanding of the significance of the night, and its loss, for humans and the natural systems upon which we depend. Knowledge is also urgently needed on suitable lighting technologies and concepts which are ecologically, socially, and economically sustainable. Unless managing darkness becomes an integral part of future conservation and lighting policies, modern society may run into a global self-experiment with unpredictable outcomes.

Patterns and predictors of fish dispersal in rivers

Abstract: Quantifying fish dispersal and identifying its general predictors is key for understanding temporal patterns in population dynamics, emigration and immigration, meta-community dynamics, many ecological processes and predicting recovery time or population responses to environmental changes. This is the first comprehensive quantitative meta-analysis of heterogeneous freshwater fish movement, aiming to determine mobile and stationary shares of fish communities, their dispersal distances and key predictors of dispersal patterns. By reviewing and analysing 160 empirical data sets from 71 studies covering 62 fishes in streams, it goes beyond previous studies of salmonids’ heterogeneous movement. Based on fitted leptokurtic dispersal kernels, the movement distances of (i) a stationary component (σstat) and (ii) a mobile component (σmob) as well as the (iii) share of each component (p) were calculated. The median movement distance of the stationary and mobile component of a fish population was 36.4 and 361.7 m, respectively. The share of the stationary individuals was high (median = 66.6%), but unrelated to movement distance. Single and multiple linear regressions as well as mixed-effects models revealed movement distances positively related to fish length, aspect ratio of the caudal fin, stream size and duration of the study. Furthermore, movement distance differed between taxonomic families. The quantitative parameters of heterogeneous fish movement provided are prerequisite to estimate time lags in fish response to river rehabilitation, temporal patterns in species dispersal, and minimum effective size of potential founder populations for species conservation and stock recovery based on minimum numbers of specimen to disperse.

Navigation impacts on freshwater fish assemblages: the ecological relevance of swimming performance

Abstract: Waterways provide many ecological and socialservices, such as water supply, navigation,freshwater reservoirs for aquatic organisms,recreation, and fisheries. However, in heavilydeveloped waterways, the diversity andproductivity of fish assemblages typicallybecome reduced, mainly due to migrationbarriers, pollution, habitat loss, and biotopesimplification. Additionally, navigation maydirectly or indirectly reduce fish assemblages,amplifying the effects of habitat destruction.This study summarizes navigation impacts toimprove the evaluation of direct navigationeffects on fish assemblages. Literature onhydraulic forces created by moving tows wasreviewed to compare the pressures induced byshipping with the biological capabilities offish, especially with their swimming speeds.Available studies of swimming performance offreshwater fishes were compiled to developgeneral models of length-specific burst, aswell as critical swimming speeds. Modelsregressing total length on burst and criticalswimming speeds were highly significant.Linking applied hydrology and hydraulicengineering with fish ecology and physiology,absolute speed was concluded to be the bestpredictor for thresholds and limitations ofhabitat use by fish. A navigation-inducedhabitat bottleneck hypothesis (NBH) wasinferred from the threshold flow velocity,determining habitat availability for fish.According to the NBH presented here, swimmingperformance of juvenile freshwater fish is themajor bottleneck for fish recruitment inwaterways, as a result of their inability towithstand bank-directed navigation-inducedphysical forces. In essence, under commonnavigation conditions, with respect to inlandwaterway morphology, channel cross section,vessel speeds, and dimensions of commercialvessels, the navigation-induced return currentsalong the shore are usually around 0.8 ms−1 (0.7–1.0 m s−1) accompanied by a0.1–0.3 m drawdown. Under such conditions, theproposed threshold for small fish survival wasestimated to be 147 mm total length at criticalswimming performance (>20 s – 60 min withoutfatigue) and 47 mm at burst performance (<20s). These theoretical findings were supportedby empirical studies of fish recruitment inwaterways. The strong dependence of fishrecruitment on hydraulic forces opens uppossibilities of formulating suitable criteriafor safe ship operation (speed and distance tobank), as well as for effective fairwaymanagement (construction and maintenance) andsustainable fish conservation (species andproduction). A more ecologically orientatedhydraulic engineering will not constraincommercial navigation and their socioeconomicbenefits, but it will substantially enhancefish recruitment in waterways and theirecological sustainability, for the overallbenefit of fish, fisheries, and society.

Streams in the Urban Landscape

Abstract: The world’s population is concentrated in urban areas. This change in demography has brought landscape transformations that have a number of documented effects on stream ecosystems. The most consistent and pervasive effect is an increase in impervious surface cover within urban catchments, which alters the hydrology and geomorphology of streams. This results in predictable changes in stream habitat. In addition to imperviousness, runoff from urbanized surfaces as well as municipal and industrial discharges result in increased loading of nutrients, metals, pesticides, and other contaminants to streams. These changes result in consistent declines in the richness of algal, invertebrate, and fish communities in urban streams. Although understudied in urban streams, ecosystem processes are also affected by urbanization. Urban streams represent opportunities for ecologists interested in studying disturbance and contributing to more effective landscape management.

Emerging threats and persistent conservation challenges for freshwater biodiversity

Abstract: In the 12 years since Dudgeon et al. (2006) reviewed major pressures on freshwater ecosystems, the biodiversity crisis in the world’s lakes, reservoirs, rivers, streams and wetlands has deepened. While lakes, reservoirs and rivers cover only 2.3% of the Earth’s surface, these ecosystems host at least 9.5% of the Earth’s described animal species. Furthermore, using the World Wide Fund for Nature’s Living Planet Index, freshwater population declines (83% between 1970 and 2014) continue to outpace contemporaneous declines in marine or terrestrial systems. The Anthropocene has brought multiple new and varied threats that disproportionately impact freshwater systems. We document 12 emerging threats to freshwater biodiversity that are either entirely new since 2006 or have since intensified: (i) changing climates; (ii) e-commerce and invasions; (iii) infectious diseases; (iv) harmful algal blooms; (v) expanding hydropower; (vi) emerging contaminants; (vii) engineered nanomaterials; (viii) microplastic pollution; (ix) light and noise; (x) freshwater salinisation; (xi) declining calcium; and (xii) cumulative stressors. Effects are evidenced for amphibians, fishes, invertebrates, microbes, plants, turtles and waterbirds, with potential for ecosystem-level changes through bottom-up and top-down processes. In our highly uncertain future, the net effects of these threats raise serious concerns for freshwater ecosystems. However, we also highlight opportunities for conservation gains as a result of novel management tools (e.g. environmental flows, environmental DNA) and specific conservation-oriented actions (e.g. dam removal, habitat protection policies,managed relocation of species) that have been met with varying levels of success.Moving forward, we advocate hybrid approaches that manage fresh waters as crucial ecosystems for human life support as well as essential hotspots of biodiversity and ecological function. Efforts to reverse global trends in freshwater degradation now depend on bridging an immense gap between the aspirations of conservation biologists and the accelerating rate of species endangerment.

Computation And Interpretation Of Biological Statistics Of Fish Populations

Abstract: Thank you for reading computation and interpretation of biological statistics of fish populations. As you may know, people have search numerous times for their favorite books like this computation and interpretation of biological statistics of fish populations, but end up in harmful downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they cope with some infectious bugs inside their laptop.

Towards a Comprehensive Catalog of Zebrafish Behavior 1.0 and Beyond

Abstract: Zebrafish (Danio rerio) are rapidly gaining popularity in translational neuroscience and behavioral research. Physiological similarity to mammals, ease of genetic manipulations, sensitivity to pharmacological and genetic factors, robust behavior, low cost, and potential for high-throughput screening contribute to the growing utility of zebrafish models in this field. Understanding zebrafish behavioral phenotypes provides important insights into neural pathways, physiological biomarkers, and genetic underpinnings of normal and pathological brain function. Novel zebrafish paradigms continue to appear with an encouraging pace, thus necessitating a consistent terminology and improved understanding of the behavioral repertoire. What can zebrafish 'do', and how does their altered brain function translate into behavioral actions? To help address these questions, we have developed a detailed catalog of zebrafish behaviors (Zebrafish Behavior Catalog, ZBC) that covers both larval and adult models. Representing a beginning of creating a more comprehensive ethogram of zebrafish behavior, this effort will improve interpretation of published findings, foster cross-species behavioral modeling, and encourage new groups to apply zebrafish neurobehavioral paradigms in their research. In addition, this glossary creates a framework for developing a zebrafish neurobehavioral ontology, ultimately to become part of a unified animal neurobehavioral ontology, which collectively will contribute to better integration of biological data within and across species.