The response of a brown trout (Salmo trutta) population to reintroduced Eurasian beaver (Castor fiber) habitat modification

Globally, freshwaters are the most degraded and threatened of all ecosystems. In northern temperate regions, beaver (Castor spp.) reintroductions are increasingly used as a low-cost and self-sustaining means to restore river corridors. River modifications by beavers can increase availability of suitable habitat for fish, including salmonids. This study investigated the response of a population of brown trout (Salmo trutta) to reintroduced Eurasian beaver (Castor fiber) habitat modifications in northern Scotland. The field site comprised two streams entering a common loch; one modified by beavers, the other unaltered. Electrofishing and PIT telemetry surveys indicated abundance of post-young-of-the-year (post-YOY) trout was higher in the modified stream. Considering juvenile year groups (YOY and post-YOY) combined, abundance and density varied with year and season. In the modified stream, fork length and mass were greater, there was a greater variety of age classes, and mean growth was positive during all seasons. Beavers had profound effects on the local brown trout population that promoted higher abundances of larger size classes. This study provides important insight into the possible future effect of beavers on freshwater ecosystems

The response of a brown trout (Salmo trutta) population to reintroduced Eurasian beaver (Castor fiber) habitat modification

This dataset supports the publication: Robert J. Needham, Martin Gaywood, Angus Tree, Nick Sotherton, Dylan Roberts, Colin W. Bean, Paul S. Kemp. (2021). The response of a brown trout (Salmon trutta) population to reintroduced Eurasian beaver (Castor fiber) habitat modification. Canadian Journal Fisheries and Aquatic Sciences.</span

Dataset in support of the Southampton Doctoral Thesis &#39;Quantification of the Response of Brown Trout (Salmo trutta) to Habitat Modification by Reintroduced Eurasian Beaver (Castor fiber): Implications for River Management in Great Britain&#39;

Dataset that supports the following Thesis &quot;Quantification of the Response of Brown Trout (Salmo trutta) to Habitat Modification by Reintroduced Eurasian Beaver (Castor fiber): Implications for River Management in Great Britain&quot; The data is also supporting the following associated publication: Robert J. Needham et al. (2021). &quot;The response of a brown trout (Salmon trutta) population to reintroduced Eurasian beaver (Castor fiber) habitat modification&quot;. Canadian Journal Fisheries and Aquatic Sciences. All data are presented in excel files, collected using electrofishing surveys and subsequent biometric measurements, Passive Integrated Transponders Telemetry studies and remote camera monitoring. Water temperature data was collected using OTT water level loggers. Rainfall data was obtained from the Lentran weather station from the MetOffice The excel files provided contains all data used for generating the following figures. </span

Valuing complex environmental goods: landscape and biodiversity in the North Pennines

Human activities may have detrimental effects on biodiversity, and appropriate economic valuation of biodiversity can provide additional motivation to protect it. To date, there are no estimates of visitor values for landscape and wildlife changes in the North Pennines (UK) and very few studies have explored competing influences of landscape and biodiversity in public preferences. Contingent valuation estimates of visitor values for the North Pennines landscape and biodiversity, as expressed in voluntary contributions, were used to assess the importance of different factors in influencing these valuations. Policy-linked scenarios were developed, each representing the outcome of a particular policy direction such as grouse-moor specific subsidies, back-to-nature subsidies, or a ban or decline in red grouse shooting. The influence of management information provision was tested and economic values were elicited for a number of alternatives. Landscape and biodiversity were both found to be important in preference formation. In particular, respondents highly valued a mosaic landscape with increases in blanket bog and the associated increases in rare and threatened birds and mammals. Notably, significant negative valuations were obtained for some of the scenarios presented. Provision of land use information did not significantly influence visitors' valuations, a surprising result given the controversial nature of one of the primary land uses, namely red grouse shooting

Assessing in-field pesticide effects under European regulation and its implications for biodiversity: a workshop report

Abstract Background Biodiversity loss is particularly pronounced in agroecosystems. Agricultural fields cover about one-third of the European Union and are crucial habitats for many species. At the same time, agricultural fields receive the highest pesticide input in European landscapes. Non-target species, including plants and arthropods, closely related to targeted pests, are directly affected by pesticides. Direct effects on these lower trophic levels cascade through the food web, resulting in indirect effects via the loss of food and habitat for subsequent trophic levels. The overarching goals of the European pesticide legislation require governments to sufficiently consider direct and indirect effects on plants and arthropods when authorising pesticides. This publication provides an overview of a workshop's findings in 2023 on whether the current pesticide risk assessment adequately addresses these requirements. Results Effects due to in-field exposure to pesticides are currently not assessed for plants and inadequately assessed for arthropods, resulting in an impairment of the food web support and biodiversity. Deficiencies lie within the risk assessment, as defined in the terrestrial guidance document from 2002. To overcome this problem, we introduce a two-step assessment method feasible for risk assessors, that is to determine (i) whether a pesticide product might have severe impacts on plants or arthropods and (ii) whether these effects extend to a broad taxonomic spectrum. When each step is fulfilled, it can be concluded that the in-field exposure of the pesticide use under assessment could lead to unacceptable direct effects on non-target species in-field and thus subsequent indirect effects on the food web. While our primary focus is to improve risk assessment methodologies, it is crucial to note that risk mitigation measures, such as conservation headlands, exist in cases where risks from in-field exposure have been identified. Conclusions We advocate that direct and indirect effects caused by in-field exposure to pesticides need to be adequately included in the risk assessment and risk management as soon as possible. To achieve this, we provide recommendations for the authorities including an evaluation method. Implementing this method would address a major deficiency in the current in-field pesticide risk assessment and ensure better protection of biodiversity