Performance of fish lift recently built at the Touvedo Dam on the Lima River, Portugal

From March 1998 to February 1999, upstream fish passage was continuously monitored by video tape analysis at the fish lift Touvedo Dam on the Lima River, northern Portugal. A total of 1194 individuals from seven species were transferred by the lift. Cyprinids were the dominant group collected, with Iberian nase Chondrostoma polylepis (Steindachner) (31.8%) being the most abundant species, followed by Iberian barbel Barbus bocagei (Steindachner) (21.1%), Iberian dace Leuciscus carolitertii (Doadrio) (19.2%) and Iberian red roach Rutilus arcasii (Steindachner) (7.1%). Brown trout Salmo trutta fario (L.) and European eel Anguilla anguilla (L.) accounted for 10.8%, whereas Atlantic salmon Salmo salar (L.) was rarely observed. Most cyprinid seasonal movements were observed in the spring and were associated with reproduction. The timing of the run varied and its beginning appeared to be mainly dependent on water temperature. Roach, dace and nase used the fish lift intensively from mid-April until the end of summer. Barbel use of the lift intensified in mid-May in association with warmer water. Salmonids migrated in June–July and autumn. Significant differences were not found in hourly activity, except for nase and barbel, in June and July, respectively. Fish passage was not related to river discharge. The relative effectiveness of the fish lift is discussed in relation to the various species.