las comunidades de peces del río guadiamar y el accidente minero ...

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La composición de especies de peces del Guadiamar tributaries (Fernández-Delgado et al, 2010), that of the Guadiamar reached the maximum value (17 species, Fig. 2; Table 2). Figure 2. Guadalquivir Drainage location (grey) in the southern Spanish region of Andalusia. Northern tributaries are identified with roman numbers and the names of their watersheds are detailed in the Table 2. Guadiamar River basin is highlighted in dark. Table 2. Northern Guadalquivir River tributaries, size of drainage basin (Km 2 ) and species composition. Área (Km 2 ) Native species Exoticspeciess Richness Guadalimar (I) 5241 7 5 12 Rumblar (II) 712 5 3 8 Jándula (III) 2570 5 4 9 Yeguas (IV) 2570 5 4 9 Guadalmellato (V) 1288 5 2 7 Guadiato (VI) 1491 6 3 9 Bembezar (VII) 1993 7 2 9 Retortillo (VIII) 358 6 3 9 Rivera de Hueznar (IX) 683 6 3 9 Viar (X) 1784 7 2 9 Rivera de Huelva (XI) 1979 10 7 17 Guadiamar (XII) 1325 10 7 17 These northern Guadalquivir tributaries shared similar drainage area and environmental conditions (climate, geology, geomorphology, hydrology and vegetation). However, both the Guadiamar River and Rivera de Huelva River mouths 29
Las comunidades de peces del río Guadiamar y el accidente minero de Aznalcóllar were located downstream from the first large dam in the Guadalquivir River main stem, which allowed the entrance of migratory species (A. Anguilla, A. boyeri, M. cephalus and L. ramada) from the estuary but interrupted it for the rest of upstream northern tributaries. Moreover, another reason for which there is an increase in species with respect to the other upstream northern tributaries was the accumulation of exotic individuals in the lower section of large Iberian drainages. This distribution is because of most exotic fish species introduced in the Iberian Peninsula are related to reservoirs (Elvira, 1995; Clavero, 2004; Clavero and Hermoso, 2011; Ribeiro and Leunda, 2012) and are asymmetrically spread, mostly downstream from reservoirs, where flow is continuous, rather than upstream, where introduced fish are not adapted to unstable stream conditions (Bernardo et al., 2003; Vinyoles et al., 2007; Ribeiro et al., 2008). Generally, the fish assemblage in Mediterranean rivers show a dominance of just a few essential and more tolerant species widely distributed accompanied by others of reduced distribution, associated to particular habitats, and of limited expansion potential (Encina et al., 2006). According to the frequency of occurrence in catches throughout the samplings in the Guadiamar basin, L. sclateri (FO = 61.5%) and S. alburnoides (FO = 50.5%) were the dominant fish species (Table 3). The first is a generalist species (Encina and Granado-Lorencio, 1997) widely adapted to the unfavorable conditions (Herrera and Fernández-Delgado, 1992; Torralva et al. 1997; Doadrio et al., 2011). This makes the southern Iberian barbel the most ubiquitous and abundant species in southern Iberian river courses (Oliva-Paterna et al., 2003a; Fernández-Delgado et al., 2010). On the contrary, S. alburnoides avoids watercourses where anthropic pollution and sediment accumulation have a strong influence (Fernández-Delgado et al., 2010). Nevertheless, the successful reproductive strategy of this species (Fernández-Delgado and Herrera, 1994; Carmona et al., 1997) promotes its large populations and widespread distribution throughout watercourses where the degree of degradation is acceptable for the species (Fernández-Delgado et al., 2010). However, focusing on the sampling sites within the affected area, frequency of occurrence changed considerably for most species. Among the dominant native species, L. sclateri maintained dominance, while S. alburnoides was almost absent. Regarding the exotics, Lepomis gibossus and Cyprinus carpio significantly increased their frequencies of occurrence to 71.4% and 64.3%, respectively, and the rest of exotic fish increased from 15.6 to 39.3% in this stretch. On the other hand, both native and exotic fish larvae caught in this affected area (Table 1) support local reproductive activity, and 30
Page 1 and 2: DEPARTAMENTO DE ZOOLOGÍA UNIVERSID
Page 4 and 5: DEPARTAMENTO DE ZOOLOGÍA UNIVERSID
Page 6 and 7: TITULO DE LA TESIS: LAS COMUNIDADES
Page 8: A mi Madre,
Page 11 and 12: A mis antiguos compañeros del Grup
Page 13 and 14: Material and Methods 39 Results 45
Page 15 and 16: ABSTRACT This PhD Thesis analyzes t
Page 17 and 18: Las comunidades de peces del río G
Page 25 and 26: ÁREA DE ESTUDIO Cuenca del río Gu
Page 27 and 28: Área de estudio Figura 1. Cuenca d
Page 29 and 30: Área de estudio farallón del Alja
Page 31 and 32: Área de estudio Principales impact
Page 34: PARTE I: Ictiofauna de la cuenca de
Page 41: Las comunidades de peces del río G
Page 48 and 49: II.1- Habitat quality affects the c
Page 50 and 51: Condición somática de L. sclateri
Page 54 and 55: Table 1. Mean habitat variable valu
Page 66 and 67: II.2- Habitat-fish community relati
Page 68 and 69: Relaciones peces/hábitat en el Gua
Page 76 and 77: Figure 2. Tributary network of the
Page 86: PARTE III: Evolución de la comunid
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Las comunidades de peces del río G
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Table 1. List of the fish species c
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Appendix 1. Environmental variables
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