THE EFFECTS OF HUMAN PRESSURES ON SEA TROUT POPULATION

Abstract

Sea trout is a species that plays a significant ecological, social, and economic role in most freshwater bodies across Northern and Western European countries, from the White Sea to the Mediterranean Sea. The decline in sea trout stocks over the past 30 years, largely due to human pressures, has raised concerns about our limited knowledge of this species’ complex and variable life cycle. Research findings and official statistics indicate that sea trout populations are in poor condition in many regions. In this study, the threats posed by human activities to the sea trout population were examined and qualified through data collection from the WGTRUTTA group experts. Additionally, based on official statistics, the population status of sea trout over the past twenty years in various European regions were assessed. This research results indicate that the overall population status of sea trout is vulnerable in most areas and requires serious attention, especially in the UK region (England, Wales, Scotland, and Northern Ireland) and Ireland. Habitat degradation —in spawning and nursery areas— in almost all studied countries poses a significant threat to the sea trout's poor population status and is recognized as the most widespread influential human factor in this study. The presence of dams, reservoirs, hydropower plants, and any other barriers in the migration route of sea trout upstream and downstream is identified as the second major and widespread threat in many of the studied countries. Climate change, recreational and commercial fisheries, and sea lice in areas where salmon aquaculture farming occurs, respectively, are other significant human factors affecting sea trout stocks, contributing to their decline in the examined countries.