Invasion of artificial ponds in Doñana Natural Park, southwest Spain, by an exotic estuarine copepod

1. During a study of five artificial brackish ponds situated in Doñana Natural Park and the Guadalquivir delta between July 2001 and June 2002, a total of six copepod species (two calanoids, three cyclopoids and one harpacticoid) were recorded. All of them are typical of brackish or estuarine habitats. 2. The estuarine calanoid copepod Acartia tonsa (originally from North America) was present in all the ponds studied. This exotic species has been found previously in European estuaries, but has not previously been recorded from artificial wetlands. 3. Both the relative and absolute abundance of the species varied significantly among months and ponds. A. tonsa was most abundant during autumn and spring, while Calanipeda aquae-dulcis was most abundant in summer. This seasonal pattern of the copepod community composition was different from that reported in studies from other European estuaries or wetlands. 4. The invasion by and dominance of A. tonsa in the area of Doñana Natural Park has important implications for the conservation of the diverse native zooplankton fauna in the natural marshes of the adjacent Doñana National Park, which includes endemic species. Copyright # 2005 John Wiley & Sons, Ltd.