Impact assessment and remediation of anthropogenic interventions on fish populations (FISHGUARD)

The disruption of longitudinal river connectivity by man-made obstacles and the stocking of fish communities with non-indigenous species or genotypes threaten the fish fauna of Belgian rivers to various extends. Obstacles impede migrations between habitats that are vital for populations, and they may restrict the gene flow between populations, thereby reducing the effective size and genetic diversity of populations and increasing the risk of local extinction. Restocking programs often involve the introduction of non-indigenous genotypes in native populations. Moreover, although stocking programs lead to the temporal and superficial enrichment of local fish communities or gene pools, they generally result in a loss of biodiversity on a regional or international scale through the homogenisation of communities and the breakdown of genetic differentiation between populations. Thus, stocking programs cannot compensate for the loss of free migration by artificial obstructions. The impact of these changes on fish populations remains largely unknown, which complicates the priorisation of spots to preserve and spots to restore. Here, we present an integrated study on Belgian waters, both in Flanders and Wallonia, which analyses fish communities, gene flow and migration patterns in the field, as well as the swimming and leaping performances of fishes under controlled conditions.D/2007/1191/41FISHGUAR

Mobility of individual roach Rutilus rutilus (L.) in three weir-fragmented Belgian rivers

Adult roach Rutilus rutilus (L.) (N = 24; 19.9-36.1 cm FL) from three highly fragmented Belgian rivers were tagged with surgically implanted radio transmitters. Their seasonal movements were observed from March to August 2004 (circum reproduction period) in river stretches delimited by two physical barriers. In the three rivers, roach displayed similar patterns of movements which were mainly influenced by the date of observation (movements increased in late April-May) and water temperature (travel distances were more important when water temperature ranged between 10 degrees C and 14 degrees C). Roach sometimes cleared physical obstacles. The mean distances travelled in each river were relatively short (max. 2.5 km) and mainly influenced by the length of the study reach, which was delimited by physical barriers

A 4-years eel research proposal submitted to the Belgian research Programme "Science for a sustainable development

The European eel (Anguilla anguilla (L).) is a widespread species in decline and current fisheries are considered outside sustainable limits. The European Commission has proposed that the primary instrument for management of European eel should be the development by Member States of "Eel Management Plans" including putting in place monitoring actions for the EU Data Collection Regulation. A research project proposal has been submitted to the Belgian Research programme “Science for a Sustainable Development”. Partners involved are institutes and universities in Flanders and Wallonia. The project is entitled “Progressive extinction of the eel: biological basis for a national recovery plan” and has the acronym ”EELBASE”. The objective is setting the scientific base for the development of the national Eel Management Plans by developing an eel database (EELBASE), designing a Belgian eel restocking programme and collecting new data about the key factors affecting the eel stocks throughout Belgium. Field studies in selected basins will focus on ecological aspects including habitat evaluation of yellow eel, silver eel escapement and impact of turbines and pumps. Another objective is to evaluate interactions between the different environmental and physiological parameters by means of an extensive assessment of physiological traits of eels of polluted and unpolluted sites. For this, several aspects of health and condition of local pre-silver and silver eel populations will be studied (a series of physiological parameters, quality of gametes, parasitological and viral agents, …).Keywords: European eel, Anguilla anguilla, management, stocks, migration, physiolog

Impact assessment and remediation of anthropogenic interventions on fish populations - (FISHGUARD)

The disruption of longitudinal river connectivity by man-made obstacles and the stocking of fish communities with non-indigenous species or genotypes threaten the fish fauna of Belgian rivers to various extents. Obstacles impede migrations between habitats that are vital for populations, and they may restrict the gene flow between populations, thereby reducing the effective size and genetic diversity of populations and increasing the risk of local extinction. Restocking programs often involve the introduction of non-indigenous genotypes in native populations. Moreover, although stocking programs lead to the temporal and superficial enrichment of local fish communities or gene pools, they generally result in a loss of biodiversity on a regional or international scale through the homogenisation of communities and the breakdown of genetic differentiation between populations. Thus, stocking programs cannot compensate for the loss of free migration by artificial obstructions. The impact of these changes on fish populations remains largely unknown, which complicates the priorisation of spots to preserve and spots to restore. Here, we present an integrated study on Belgian waters, both in Flanders and Wallonia, which analyses fish communities, gene flow and migration patterns in the field, as well as the swimming and leaping performances of fishes under controlled conditions.Global change, Ecosystems and Biodiversit