Long-term monitoring of fish (abundance and distribution) in Doñana Wetlands 2004-2019

Abstract

The monitoring of the fish community in Doñana wetlands was initiated in 2004 as part of the Monitoring Program of Natural Resources and Processes. The aim was to obtain a temporal and continuous series of data in the abundance and distribution of fish species to analyze the evolution of their numbers and estimates biodiversity values. Data were recorded annually between 2004-2019 by more than 2 members of the monitoring team which performed samplings in different locations twice per year in winter-spring and summer seasons when the study sites are flooded. The fishes were sampled at the 139 stations classified according to their location (on either aeolian sands or marshland). Funnel traps were used as a sampling method. Between 5-9 funnel traps were randomly distributed (until 50 cm of depth) in each location, depending of the flooded area and depth. The traps were left for 24 hours and emptied the content into white sorting pans. Individuals were counted and identified until the maximun taxonomic level in the field and realease. During samplings, it was identified 15 families. The most abundances were Poecilidae and Cyprinidae.

Data recorded during the surveys included species identification, number of individuals, sex and life stage (pupa, larvae, inmature, mature) of the organisms when possible, as well as the time and georreferenced data of the observation. Between 2004-2007 data was registered in Excel file and since 2008 data was recorded in CyberTracker sequence). The protocol used has been supervised by researchers and the data have been validated by the members who performed the sampling.