Research themes

Using experimental, field and modelling approaches, our research spans a wide range of themes primarily focused on understanding and mitigating the impacts of human activity of aquatic environments.  

Passage at river infrastructure

The development of effective fish passage and screening strategies are essential for mitigating impacts of water resource infrastructures. Structures such as: 

• weirs
• culverts
• pumping stations 

We are also developing more environmentally friendly means of generating energy, for example hydropower, and marine or coastal renewable energy technology.  

We employ various techniques, ranging from still water tank and open channel flume trials in the lab to field-based telemetry studies. This ensures fish and other aquatic organism passage issues are explored across as range of spatial and temporal scales. Examples include:  

• development and testing of low-cost fish passage solutions, for example Cylindrical Bristle Clusters, eel and lamprey tiles for gauging and other sloped weirs
• quantifying the efficacy of physical wedge-wire and horizontal or vertical bar screens for diverting juvenile coarse fish from water intakes
• use of acoustic and PIT telemetry to assess the impact of tide gates and novel modifications to them on the migration of European eel (Anguilla anguilla) and sea trout (Salmo trutta)

Sustainable hydropower

As the largest global generator of renewable electricity, hydropower helps reduce dependence on fossil fuels and meet renewable energy targets. However, hydropower can still have significant environmental impact and is considered one of the biggest threats to freshwater biodiversity. Developments disrupt natural flow and sediment regimes, fragment habitat for aquatic organisms and injure or kill fish that enter turbines.

In collaboration with domestic and international partners, our research has included:  

• assessment of fish injury and delay to migration at low-head hydropower turbines, for example Archimedes Screws
• use state-of-the-art pressure chambers to quantify the impact of barotrauma associated with fish passage through turbines and spillways
• development of more sustainable hydropower operation and planning practices in parts of the Global South   

Fish behaviour

A large amount of ICER research aims to understand aspects of fish behaviour. This is to either improve fundamental understanding or to help address applied problems. Fundamental topics have investigated the behavioural ecology of brown trout in stable groundwater-fed rivers. Investigation has also taken place in to the role of biotic, or collective behaviour and abiotic or hydrodynamics factors on fish response to static visual cues. 

Applied research has centred around understanding response to sensory pollutants such as anthropogenic noise and artificial light at night. Knowledge of fish behaviour is applied to mitigating impacts of river infrastructure. For example, by informing development of behavioural guidance or deterrent systems. Much of our fish behaviour research has strong links with other research themes, including:

• investigating the extent to which being part of a school influences fish response to acoustic stimuli, using the minnow (Phoxinus phoxinus) as a model species
• fish response to accelerating velocity gradients, a common hydrodynamic condition encountered by downstream moving fish at river infrastructure
• development of an agent-based model of the upstream movement behaviour of river lamprey (Lampetra fluvialilis), parameterised using fine-scale (2D) acoustic telemetry data  

River restoration

A large and increasing number of rivers undergo physical habitat restoration to mitigate the negative impacts of channel modification and changes in land-use. Monitoring ecological change following river restoration is of key importance in addressing questions relating to which techniques work, where, over what time scales and to understand the principle underlying mechanisms.

We also assess, test and develop tools that can be used to aid river restoration focused decision making.  

Our river restoration research has included:  

• measuring macroinvertebrate response to physical habitat restoration, including weir removal and gravel augmentation projects in chalk streams
• quantifying effects of low oxygen on the incubation of Atlantic salmon (Salmo salar) to determine levels of mortality and adaptability between populations
• validating coarse-resolution rapid assessment protocol estimates of fish passability at river barriers to inform catchment wide decisions on mitigation.  

Species (re-)introductions

The desire to “rewild” the countryside with native species extirpated by humans and the restoration of ecological function are two primary reasons behind species reintroductions. Conversely, the introduction of non-native species is one of the greatest threats to biodiversity and a priority for conservation.

Our research has assessed these topics within a freshwater context and has included:

• feasibility of reintroducing the burbot (Lota lota), an extirpated freshwater fish, to the British Isles
• assessing fish communities and migration at Eurasian beaver (Castor fiber) reintroduction sites in Scotland and England
• understanding the influence of anthropogenic barriers on the dispersal of the invasive American signal crayfish (Pacifastacus leniusculus)

Enhancing sustainable marine fisheries management 

We adopt an interdisciplinary system thinking approach to understand the challenges and potential solutions of enhancing sustainable management of marine fisheries. 

This enables us to visualise complex systems that comprise environmental, social and economic components. This facilitates the identification of synergies, trade-offs, unintended consequences and potential for conflict and impediments to progress. 

Research that focuses on systems dynamics has included the following projects that: 

• adopt innovative social science approaches to understand the response of fishing communities to policy changes and economic shocks
• mine existing historic data in conjunction with the use of remote vessel monitoring data to understand shifts in fishing activity over time
• use artificial intelligence and machine learning to quantify fishing in data poor context through the interrogation of satellite imagery and other remote sensing techniques