Variability in Population Traits of a Sentinel Iberian Fish in a Highly Modified Mediterranean-Type River

Abstract

Human pressures on water resources have been suggested as a driver of biological traits that induce changes in native fish populations. This study highlighted the interplay between environmental stress factors, mostly related to flow regulation, and the longitudinal river gradient in biological traits such as the growth, size structure and somatic condition of a sentinel fish, Luciobarbus sclateri. We found an increase in size-related metrics and somatic condition at population levels associated with downstream reaches, although fragmentation and habitat alteration, flow regime alteration and the abundance of non-native fish were also significantly involved in their variability. Age-related parameters and growth were only explained by flow regime alterations and the abundance of non-native fish species. The high plasticity observed in L. sclateri population traits suggests that this is a key factor in the species adaptability to resist in a strongly altered Mediterranean river basin. However, the interplay of multiple stressors plays an important role in fish population dynamics and could induce complex responses that may be essential for long-term monitoring in sentinel species.

The Gut Contents of the Squalius cii in a Permanently Interrupted River System, the Karamenderes River

“…The dams built on such unstable rivers cause an additional change in the flow regimes by reshaping habitats (Alexandre et al, 2013;Sánchez-Pérez et al, 2021). This also alters fish populations (Baumgartner, 2007;Branco et al, 2017;Sánchez-Pérez et al, 2021) and their natural feeding habits (Magoulick & Kobza, 2003). The results of the present study support these propositions by revealing that there was a variation in the feeding strategy of S. cii at the stations located in the upper and the lower sections of the dam on the Karamenderes River.…”

“…The features of the streams in the Mediterranean are generally unstable due to variable temperatures and flooding (Oliva-Paterna et al, 2003). The dams built on such unstable rivers cause an additional change in the flow regimes by reshaping habitats (Alexandre et al, 2013;Sánchez-Pérez et al, 2021). This also alters fish populations (Baumgartner, 2007;Branco et al, 2017;Sánchez-Pérez et al, 2021) and their natural feeding habits (Magoulick & Kobza, 2003).…”

Ecology and Conservation of Freshwater Fishes Biodiversity: We Need More Knowledge to Develop Conservation Strategies

“…Other studies highlight the interaction between ecological stress factors and biological traits and the use of sentinel species for the long-term monitoring of environmental status. This is the case with the study of Sánchez-Pérez et al [11], where they analyze biological traits such as the growth, size structure, and somatic condition of the Southern Iberian barbel (Luciobarbus sclateri (Günther, 1868)) in a stressed Mediterranean river.…”