With the CONNECTFISH project, IHCantabria will evaluate the impact of dams on Iberian fish fauna in a multidisciplinary way

Research staff of the Environmental Hydraulics Institute of the Universidad de Cantabria (IHCantabria) contributes to the optimization of decision making in the management and conservation of Spanish fish communities, through the prioritization of the location of future dams or the demolition of existing ones, based on the development of efficient and easy-to-apply tools, at different geographical scales and from different perspectives. This contribution is offered through the CONNECTFISH project.

The title of this project is “Analysis of the ecological connectivity of dams in relation to the conservation status of Iberian fishes: a multidisciplinary approach” (CONNECTFISH). Its development is scheduled between July 2023 and December 2025, under the leadership of David Galicia Paredes, professor at the University of Navarra, and with the participation of the following researchers from the Continental Ecosystem Group of IHCantabria: José Barquín Ortiz, Francisco Peñas Silva, Amaia Angulo Rodeles, Alexia González and María Cristina Morán Luis.

The partners of this project are the Institute of Biodiversity and Environment (BIOMA) of the University of Navarra and IHCantabria. Its development is financed by the Ministry for Ecological Transition and the Demographic Challenge, the Biodiversity Foundation, the Spanish Recovery, Transformation and Resilience Plan and the Next Generation Funds.

CONNECTFISH is a project that aims to assess the impacts of dams on the Iberian fish fauna in a multidisciplinary way. It proposes to analyze the biological and social aspects related to the ecosystem services provided by rivers, as well as the social perception of them. For the development of this project, it is necessary to evaluate the conservation status and environmental requirements of Iberian fish, to analyze the impact on the populations of these species of the construction or elimination of dams and to evaluate the social perception that river users have of dams and river restoration. “The result of this analysis will allow us to have a tool for decision making in the prioritization and location of future dams, or the demolition of existing ones,” explains Amaia Angulo Rodeles, one of the IHCantabria researchers involved in this project.

One of the greatest impacts on freshwater biodiversity is the construction of dams, which fragment and modify river ecosystems. The effects of river fragmentation are evident in migratory fish, whose populations may decline or be eliminated from large river systems due to obstacles such as dams. Although this impact is most visible for migratory species, sedentary fish – or fish that migrate within the river (potamodromes) – are also affected by the presence of barriers. This was the problem that motivated the development of the CONNECTFISH project.

In order to meet the objectives of this project, it has been divided into two distinct blocks. The first will focus on the large-scale study of the populations of all Spanish fish species in relation to connectivity. The second block will analyze, at the regional level -in three Cantabrian basins of Navarre, the Basque Country and Cantabria-, the impact of barriers on Atlantic salmon and brown trout populations. The focus on a small study area, with two well-studied species and high data availability, will allow a further step in assessing the impact of barriers and the potential effect of river connectivity restoration, in a more quantitative way. Subsequently, the social perception of river users about dams and river restoration will be analyzed.

With the development of this project, several results are expected to be obtained, such as the following: a spatial distribution models of native fish species (about which will be published on the project website); a new highly customizable tool, which allows adding different variables according to data availability and the objective to be achieved by the analysis; meta-population models of trout and salmon in three Cantabrian basins, to assess the impact of barriers on these populations; a new database that will allow analyzing, from a social and cultural point of view, what is the social perception about dams, the impacts and the ecosystem services they offer. All results will be published on the project website, in international scientific journals and at scientific events. Different products will be offered, from the informative, technical and scientific aspects.