Brown Trout (Salmo trutta) Abundance and Biomass in Mediterranean Rivers: Environmental, Genetic, and Management Drivers
Brown trout (Salmo trutta) populations at the southern edge of the species’ distribution are increasingly exposed to interacting climatic, biotic, genetic, and anthropogenic pressures. This study provides an integrative assessment of the drivers of variation in brown trout density, biomass, and size...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2026 |
| País: | España |
| Institución: | Institut de Recerca i Tecnologia Agroalimentàries (IRTA) |
| Repositorio: | IRTA Pubpro. Open Digital Archive |
| OAI Identifier: | oai:dnet:irtapubpro__::67d6ee0513f184147090585d33916e7d |
| Acceso en línea: | https://hdl.handle.net/20.500.12327/5243 https://doi.org/10.3390/fishes11040217 |
| Access Level: | acceso abierto |
| Palabra clave: | 574 |
| Sumario: | Brown trout (Salmo trutta) populations at the southern edge of the species’ distribution are increasingly exposed to interacting climatic, biotic, genetic, and anthropogenic pressures. This study provides an integrative assessment of the drivers of variation in brown trout density, biomass, and size structure across six Mediterranean river basins in Catalonia (NE Iberian Peninsula), based on long-term standardized electrofishing surveys (2016–2025; 88 sites). Generalized linear mixed models revealed that mean summer temperature, genetic introgression from hatchery-derived Atlantic lineages, and the density of introduced fish species were the most consistent negative predictors of total density, biomass, and juvenile abundance (<120 mm FL). Hydrological and nutrient variables showed comparatively weak or non-significant effects relative to thermal and biotic predictors. Fishing regulations significantly influenced the biomass and density of larger trout (>220 mm FL), with lower values in harvest-allowed sections, whereas total density was less responsive to regulation. These findings indicate that Mediterranean brown trout populations are primarily constrained by thermal conditions, genetic integrity, and biological invasions, with implications for conservation and fishery management under ongoing climate warming. |
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