PROSPER 101105250 - MSCA Post Doc European Fellowship 2022 - (Phenotypic diversity and resilience to environmental change in freshwater fish)
Lead Research Organisation:
Bournemouth University
Department Name: Faculty of Science and Technology
Abstract
Europe's rivers are highly fragmented by human constructed barriers that block the movement of fish, with this fragmentation driving substantial declines in freshwater fish diversity and abundance. The EU Biodiversity Strategy aims to remove riverine barriers wherever possible so that 25000 km more river will be free-flowing in Europe by 2030. However, barrier removal is only occasionally feasible and so engineered fish passes provide alternative re-connection tools. The passes provide an easier route for fish to use to bypass the barrier. Although these fish passes are frequently on rivers with a diverse fish assemblage, they tend to be constructed to primarily facilitate the passage of diadromous fishes, especially anadromous salmonid fishes, despite most fish species being impacted by the fragmentation. This inter-specific selectivity of fish passes is potentially compounded by their intra-specific selectivity, where only specific phenotype groupings are able to use the pass successfully. Thus, while fish passes are used frequently to provide river reconnection in Europe, the extent to which they impose new selection pressures on fish communities - and the associated consequences - remain high uncertain.
Our project overcomes this high uncertainty in fish passage selectivity by bringing together an outstanding European researcher with potential to develop into a global science leader with a research group with strong competencies in fish tracking technologies and fish behaviour assessment. Together, we generate new knowledge on the performance of fish populations and communities using fish passes on the lower River Severn in western Britain through application of the latest biotelemetry methods. We use these data to then build novel agent based models that predict the ecological consequences of barriers and fish passes. These results provide river managers with the knowledge to better resolve river fragmentation that works for all species.
Our project overcomes this high uncertainty in fish passage selectivity by bringing together an outstanding European researcher with potential to develop into a global science leader with a research group with strong competencies in fish tracking technologies and fish behaviour assessment. Together, we generate new knowledge on the performance of fish populations and communities using fish passes on the lower River Severn in western Britain through application of the latest biotelemetry methods. We use these data to then build novel agent based models that predict the ecological consequences of barriers and fish passes. These results provide river managers with the knowledge to better resolve river fragmentation that works for all species.
Organisations
People |
ORCID iD |
| Robert Britton (Principal Investigator) |
Publications
Blonska D
(2024)
Passage efficiency through fishways of species of the family Cyprinidae and their management implications for fragmented rivers.
in Scientific reports
Blonska D
(2025)
Restoration of river connectivity enables long-distance spawning migrations in a potamodromous fish.
in Journal of environmental management
| Description | Although the award is still active, the results to date have revealed two main outcomes relating to (1) River fish behaviours and phenotypic variability; and (2) The use of fish passes by non-salmonid river fishes and this this is affected by differences in the behaviour of individuals. These can be summarised as: 1. River fish behaviours and phenotypic variability: - Using acoustic telemetry, the results have revealed high variability in the behaviour of non-salmonid river fish, with some individuals that are highly active with substantial home ranges, whereas others have much smaller home ranges - Stable isotope analysis (ratios of 12C:13C and 14N:15N) revealed that individuals that move more have diets based on natural prey items, whereas those that move across smaller areas have diets more strongly associated with baits introduced into the river by recreational anglers. - Scale cortisol concentrations (as a biomarker of activity and chronic stress) are higher in individual fish are that move greater distances - Stable isotope data and scale cortisol data can be used as proxy measures within investigations of phenotypic variability in river fish populations. 2. The use of fish passes by non-salmonid river fishes and this this is affected by differences in the behaviour of individuals - The results to date have revealed that the extent of river connectivity (and, accordingly, river fragmentation) has a strong influence on the home range sizes of all individual fish, irrespective of their phenotypic traits. - Where rivers have multiple barriers (e.g. weirs) that do have not been subject fish passage mitigation or remediation then home range sizes remain limited - Where fish passage mitigation and remediation structures have been installed on barriers, some individuals almost immediately use these to pass the previously impassable barrier; where these structures are installed on multiple and sequential barriers, these individuals can move freely across large river distances (total maximum distance of river covered by an individual when fragmented: <15km; total maximum distance of river covered by an individual when the river is reconnected using passage structures on previously impassable structures: >100km) - Although fish pass structures on weirs enable free movement of fish across much larger spatial areas, artificial selection pressures remain, with passage selection for active phenotypes with low angler bait dietary contributions and relatively high scale cortisol levels. Work is continuing on the award to predict the implications of these ecological/ engineering interactions for lowland rivers and their fish populations |
| Exploitation Route | The results outlined above can be used in decision-making relating to river management, specifically in relation to managing highly modified and fragmented rivers. |
| Sectors | Construction Energy Leisure Activities including Sports Recreation and Tourism Other |
| Description | Stakeholder workshops |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Professional Practitioners |
| Results and Impact | Results dissemination within wider workshops for discussing the outcomes of river reconnection on the River Severn and future research and monitoring plans, with discussions relating to applied ecology and river management outcomes. |
| Year(s) Of Engagement Activity | 2024,2025 |