| Summary: | Natural swimming pools are artificially created ponds, where the ecological processes occurring in the natural water bodies are recreated. These ponds constitute recreational spaces of low environmental impact, because no chemical products for water purification are used. Clarifying and purifying of the water is achieved through biological filters and plants growing in the system. Since no conventional chemicals are added to water, these ponds are rapidly colonized by a wide range of organisms such as plankton, macro-invertebrates and some vertebrates. Therefore, natural swimming ponds promote biodiversity maintenance and increase the aesthetic value of the surrounding landscape meaning. In this work are presented the results of faunal surveys performed in several natural swimming pools across Portugal. The zooplankters more frequently found were: the copepods A. robustus and C.numidiacus; the cladocerans Ceripdaphnia pulchella, Daphnia longispina/pulex, Simocephalus vetulus, Alona sp. Chidorus sphaericus and the rotifer Keratella cochlearis. The most emblematic macro-invertebrates found, were the dragonflies Anax imperator, Coenagrion scitulum, Crocothemis erythraea, Diplacodes levebvrei, Erythromma lindenii, Gomphus pulchellus, Ischnura graellsi, Libellula quadrimaculata, Orthetrum cancellatum Orthetrum chrysostigma and Orthetrum coerulescen. Amphibians such as, the newts Lissotriton boscai, Triturus marmoratus and Triturus pygmaeus; the salamander Pleurodeles waltl, the tree frog Hyla meridionalis; the frog Rana perezii; the toads, Pelobates cultripes and Bufo spinosus use natural swimming pools for reproduction. The most common reptiles were the viperine water snake (Natrix maura) and the terrapins (Mauremys leprosa) were frequently found. Concerning birds, squacco heron (Ardeola ralloides), grey heron (Ardea cinerea) and kingfisher (Alcedo atthis) were the commonest species found in the pools surroundings. The presence of otter (Lutra lutra) was also detected. Some of the mentioned species are considered to ...
|
|---|