Clear trends in the biotic traits of macroinvertebrates were evident over time, especially dispersal abilities, adult ability to exit the water, body shape and body size. These trends have been used to inform a conceptual model of the filters that act at different stages of stream development to limit colonization from the regional species pool of macroinvertebrates. 

Lake sediment cores from around Kangerlussuaq in West Greenland were sampled over a precipitation gradient to test whether nitrogen deposition has influenced recent limnological change.  Biological and chemical change inferred from algal pigments, diatom and stable isotopes was greatest after AD1950 in lakes receiving higher nitrogen deposition loads and located in non-vegetated catchments.    

Methane is a largely unknown carbon source in running waters, but recent stable isotope analysis has suggested some chalk-stream invertebrates such as cased caddis (Trichoptera) consume methane-derived carbon. As dominant primary consumers, the potential for trophic transfer of methane-derived carbon is considerable. We provide new, comprehensive evidence that methane-fuelled riverine food webs are far more widespread than previously thought.

Animals adapt their behaviour to changes in the environment and yet integration of behavioural ecology in conservation management is uncommon. Understanding behavioural responses to an environmental change and predicting resulting effects on population characteristics will assist in designing optimal management strategies. Here we use an individual-based model to investigate the impact of flow, weed-cutting and predator management on salmonid populations.

Nutrient uptake was quantified in 12 Svalbard rivers. Demand for NO₃^- and PO₄^- was low, but demand for NH₄⁺ was high and associated positively with water temperature, algal biomass and transient storage zone area. Uptake of NH₄⁺ increased when added with acetate, suggesting NH₄⁺ assimilation by microbial communities is mediated by labile DOC availability in these Arctic river systems.

Swimming and shoaling behaviour of parasite-infected guppies was investigated using an open channel flume. At an individual level, localised flow velocities and host size altered swimming behaviour, specifically refuge use and rate of movement. At the population level, both an increase in flow rate and parasite infection reduced shoaling behaviour.

The keystone macrophyte R. pseudofluitans is well-known as a biological engineer in chalk streams, often controlling community assemblage. Threatened by climate change and drought, little is known about the responses of this important macrophyte to low-flow conditions. Under experimental conditions, flow was found to be critically important in determining plant morphological trait and physiological stress responses.  

Sewer misconnections connect domestic appliances to surface water sewers, causing intermittent release of domestic sewage directly to rivers. There has been very little study of the ecological impacts of misconnection discharge to date, despite the potential threat it poses to surface water ecosystems. In this study, diatom communities have been used as ecological indicators to investigate the impact of misconnections.

We used a long-term dataset of invertebrates and river discharge data to explore functional diversity in floodplains.  A vector for transferring aquatic nutrients, invertebrates represent a key functional floodplain component. Interannual community responses to flood-driven disturbance indicate that climate change induced flow variability may have a significant impact on cross-ecotone exchanges.

Recent theoretical studies suggest dendritic networks alter dispersal and species interactions compared to more traditional linear or homogenous landscape views. We investigated landscape structure and community diversity influences on colonization patterns of six protist and a rotifer species using silicon tubing experiments, allowing for active dispersal. Our findings suggest landscape geometry, species traits, and species interactions significantly influence colonization patterns.

The Welland is one of 10 "Pilot Catchment" projects set up in 2011 to produce a rapid improvement in Ecological Status of rivers through partnership between the Environment Agency and non-statutory bodies. Managed by the Welland Rivers Trust, under the umbrella of the Welland Valley Partnership, will it achieve this? If so, can lessons learnt be transferred?

Stonefly predators are predicted to increase their range in alpine stream systems with climate change. Using streamside mesocosm channels, we found that stonefly predation reduced algal grazer abundance and increased trophic height. Community size structure was also positively skewed. These results suggest that predator range expansion in alpine streams will alter biotic interactions, ecosystem function and ultimately increase extinction risks.

The data were gathered monthly between 2006 to 2012 from sites on the Bleaklow Plateau, Peak District. Samples were collected from restoration and control (bare and vegetated) sites. Treatment of bare peat significantly affected DOC concentrations over time. There does not appear to be a simple relationship between bare site re-vegetation and DOC.

This talk presents a series of 70 hour experiments investigating rates of photo- and bio-degradation of organic carbon to CO₂ in surface-waters draining a peat-dominated upland-catchment in the North Pennines.  Findings suggest that up to 60% of DOC and 50% of the suspended-sediment is lost in the 70 hours.  These findings will help improve the accuracy of peatland carbon budgets.

Restoration of riparian tree cover is currently recognised as a potential climate change adaptation for stream ecosystems. Whilst the thermal consequences of such strategies are well quantified, effects on community-level trophic interactions, and how these may ultimately affect fish production, are poorly understood. This study investigated effects of restoration on macroinvertebrate trophic dynamics and Salmonid populations in upland streams.