Recent trends among aquatic biota in the catchment of the River Wye (Wales) and the effects of Riparian management

Rod catches of Atlantic salmon (Salmo salar) from the River Wye were previously the greatest in England and Wales. However, a 30-year decline in catches of salmon and brown trout (S. trutta ) prompted management action. Since 1996, the Wye and Usk Foundation have excluded livestock, managed riparian trees, protected banks, cleared migratory barriers and limed selected tributaries. The aim was to enhance salmon habitat and extend spawning opportunities. The outcomes of such activities in Britain are still poorly understood. This thesis i) identified variations in the water quality, aquatic invertebrates and salmonids of the Wye catchment ii) evaluated the impact of recent management on habitats and aquatic organisms iii) assessed whether any larger-scale factors could explain management effects. Because no suitable project-specific data were collected, routine monitoring data and surveys were applied in the most applicable post-hoc experimental designs. Ecological quality varied widely among the Wye's tributaries. Combined biotic indices supported the need to mitigate acidification in some upland streams and reduce diffuse nutrients in the lower catchment. Riparian management appeared to reduce bank poaching and increase algae by comparison with reference streams. Post-treatment invertebrate communities were richer in recently managed streams than in controls. However, there was no evidence that management reversed the decline in salmonid populations. The typical life-cycle of salmonids in the Wye might delay response to management, but this effect cannot be evaluated with only six years' post-treatment data. Alternatively, local effects could be masked by larger-scale trends. In particular, salmonid abundance in the Wye declines significantly with increasing summer temperatures, decreasing summer rainfall and discharge. I conclude that riparian management has had some of the desired outcomes at the reach or tributary scale. However, salmonid numbers in the Wye potentially reflect climatic effects, implying a need to consider climate-change in future management action.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Recent trends among aquatic biota in the catchment of the River Wye (Wales) and the effects of Riparian management

Rod catches of Atlantic salmon (Salmo salar) from the River Wye were previously the greatest in England and Wales. However, a 30-year decline in catches of salmon and brown trout (S. trutta ) prompted management action. Since 1996, the Wye and Usk Foundation have excluded livestock, managed riparian trees, protected banks, cleared migratory barriers and limed selected tributaries. The aim was to enhance salmon habitat and extend spawning opportunities. The outcomes of such activities in Britain are still poorly understood. This thesis i) identified variations in the water quality, aquatic invertebrates and salmonids of the Wye catchment ii) evaluated the impact of recent management on habitats and aquatic organisms iii) assessed whether any larger-scale factors could explain management effects. Because no suitable project-specific data were collected, routine monitoring data and surveys were applied in the most applicable post-hoc experimental designs. Ecological quality varied widely among the Wye's tributaries. Combined biotic indices supported the need to mitigate acidification in some upland streams and reduce diffuse nutrients in the lower catchment. Riparian management appeared to reduce bank poaching and increase algae by comparison with reference streams. Post-treatment invertebrate communities were richer in recently managed streams than in controls. However, there was no evidence that management reversed the decline in salmonid populations. The typical life-cycle of salmonids in the Wye might delay response to management, but this effect cannot be evaluated with only six years' post-treatment data. Alternatively, local effects could be masked by larger-scale trends. In particular, salmonid abundance in the Wye declines significantly with increasing summer temperatures, decreasing summer rainfall and discharge. I conclude that riparian management has had some of the desired outcomes at the reach or tributary scale. However, salmonid numbers in the Wye potentially reflect climatic effects, implying a need to consider climate-change in future management action

Transparency in non-technical summaries to sustain the 3Rs in respiratory diseases research

Non-Technical Project Summaries (NTS) are legal documents that were first introduced by the Directive 2010/63/EU to enhance transparency within scientific animal experimentation. Researchers intending to conduct biological research on animal models must fulfil the NTS requirements by outlining their proposed use of animals and how they plan to implement the Three Rs (replacement, reduction and refinement of animal use) in their experiments. This study outlines a novel systematic analysis approach that enables the assessment of NTS transparency based on the accuracy of reporting of certain Three Rs-specific information. This potentially customisable strategy could help toward the development of practical guidelines for use by Animal Welfare and Ethical Review Bodies (AWERBs) in establishments conducting animal research, in the process of scrutinising NTS during their pre-submission review of proposed licence applications. This could help to identify gaps in reporting of Three Rs-specific information relating to the planned animal experiments, which represents a remarkable step toward achieving greater openness in scientific communication. This study supports the concept that NTS transparency can promote the implementation of non-animal alternatives in fields where this is currently lacking, such as respiratory disease research. Although NTS were originally conceived as informative documents for a lay audience, we can conclude that data in NTS can be successfully used as a basis for systematic analysis. By reviewing the NTS, the experimental limitations of the currently available replacement strategies can also be highlighted, potentially pinpointing where there is a need for future method development

NGS barcoding reveals high resistance of a hyperdiverse chironomid (Diptera) swamp fauna against invasion from adjacent freshwater reservoirs

Abstract Background Macroinvertebrates such as non-biting midges (Chironomidae: Diptera) are important components of freshwater ecosystems. However, they are often neglected in biodiversity and conservation research because invertebrate species richness is difficult and expensive to quantify with traditional methods. We here demonstrate that Next Generation Sequencing barcodes (“NGS barcodes”) can provide relief because they allow for fast and large-scale species-level sorting of large samples at low cost. Results We used NGS barcoding to investigate the midge fauna of Singapore’s swamp forest remnant (Nee Soon Swamp Forest). Based on > 14.000 barcoded specimens, we find that the swamp forest maintains an exceptionally rich fauna composed of an observed number of 289 species (estimated 336 species) in a very small area (90 ha). We furthermore barcoded the chironomids from three surrounding reservoirs that are located in close proximity. Although the swamp forest remnant is much smaller than the combined size of the freshwater reservoirs in the study (90 ha vs. > 450 ha), the latter only contains 33 (estimated 61) species. We show that the resistance of the swamp forest species assemblage is high because only 8 of the 314 species are shared despite the close proximity. Moreover, shared species are not very abundant (3% of all specimens). A redundancy analysis revealed that ~ 21% of the compositional variance of midge communities within the swamp forest was explained by a range of variables with conductivity, stream order, stream width, temperature, latitude (flow direction), and year being significant factors influencing community structure. An LME analysis demonstrates that the total species richness decreased with increasing conductivity. Conclusion Our study demonstrates that midge diversity of a swamp forest can be so high that it questions global species diversity estimates for Chironomidae, which are an important component of many freshwater ecosystems. We furthermore demonstrate that small and natural habitat remnants can have high species turnover and can be very resistant to the invasion of species from neighboring reservoirs. Lastly, the study shows how NGS barcodes can be used to integrate specimen- and species-rich invertebrate taxa in biodiversity and conservation research

Supplemental Material - Transparency in Non-Technical Project Summaries to Promote the Three Rs in Respiratory Disease Research

Supplemental Material for Transparency in Non-Technical Project Summaries to Promote the Three Rs in Respiratory Disease Research by Martina Bonassera, Esther Clews and Kelly BéruBé in Alternatives to Laboratory Animals</p

Juvenile salmonid populations in a temperate river system track synoptic trends in climate

Widespread declines among Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) over recent decades have been linked to pollution, exploitation and catchment modification, but climate change is increasingly implicated. We used long-term, geographically extensive data from the Welsh River Wye, formerly a major salmon river, to examine whether climatically mediated effects on juveniles (>0+) might contribute to population change. Populations of Atlantic salmon and brown trout fell across the Wye catchment, respectively, by 50% and 67% between 1985 and 2004, but could not be explained by pollution because water quality improved during this time. Stream temperatures, estimated from calibrations against weekly air temperature at eight sites, increased by 0.5–0.7 °C in summer and 0.7–1.0 °C in winter, with larger tributaries warming more than shaded headwaters. Rates of winter warming were slightly greater after accounting for the effect of the North Atlantic Oscillation (1.1–1.4 °C). However, warming through time was smaller than measured variations among tributaries, and alone was insufficient to explain variations in salmonid density. Instead, population variations were best explained in multilevel mixed models by a synoptic variate representing a trend towards hotter, drier summers, implying interactions between climate warming, varying discharge and fluctuations in both brown trout and salmon. Taken alongside recent data showing effects of warming on survival at sea, these data suggest that Atlantic salmon might be jeopardized by future climatic effects in both their marine and freshwater stages. Effects on nondiadromous brown trout also imply climatically mediated processes in freshwaters or their catchments. Climate projections for the United Kingdom suggest that altered summer flow and increasing summer temperatures could exacerbate losses further in these species, and we advocate management actions that combine reduced abstraction with enhanced riparian shading

Tropical Marine and Brackish Ecosystems

Climate change and non-infectious fish disordersUnited Kingdo