Tesis doctoral de Lluís Benejam Vidal
The aim of this thesis is to contribute to the use of freshwater fish as ecological indicators in the mediterranean basin. In the first article we found that although most biological indices were correlated, fish reflected different ecological aspects due to their particular features. In the second article the stream flow regimes of six mediterranean basins were studied. A decrease of streamflow and aquifer levels was detected, despite no observed decrease of rainfall precipitation. Of the thirty metrics tested to detect sites impacted by water abstraction, we detected four significant fish metrics. Furthermore, the role of biotic indices when the river is artificially dry is discussed. In the third article we found that species composition in the pelagic zone varied significantly during the drawdown with higher proportion of bleak (a. Alburnus) during the days of worst water quality, confirming that bleak is more tolerant than roach (r. Rutilus) to poor water quality. The weight#length relationship of roach and bleak also varied significantly during the drawdown with close relationship between water quality and fish condition. In the fourth article the condition and fecundity of freshwater fishes were assessed in a highly polluted reservoir (flix reservoir). We have shown significant increases of delt anomalies and ectoparasite prevalences and decreases in condition and fecundity of several freshwater fish at the impacted area. The responses to the pollutants were species-specific and common carp was the species that showed more markedly the effects.
Datos académicos de la tesis doctoral «Fish as ecological indicators in mediterranean freshwater ecosystems«
- Título de la tesis: Fish as ecological indicators in mediterranean freshwater ecosystems
- Autor: Lluís Benejam Vidal
- Universidad: Girona
- Fecha de lectura de la tesis: 22/12/2008
Dirección y tribunal
- Director de la tesis
- Emili García Berthou
- Tribunal
- Presidente del tribunal: narcis Prat fornells
- adolfo De sostoa fernandez (vocal)
- sovan Lek (vocal)
- lluís Zamora hernández (vocal)