Habitat Preferences of Larval Lamprey. Application of an European Directive Aimed to Conservation

Conservation and management of threatened lamprey populations requires the ability to evaluate and predict patterns in larval habitat preferences at several spatial scales. In this study we describe the methodological approach used to determine the distribution of the European lampreys Lampetra fluviatilis and L. planeri in Portugal and, at the same time, identify variables chosen for habitat selection at three distinct geographic scales: regionally, river basin and micro-habitat. About 400 sampling stations were selected to detect the occurrence of Lampetra sp. ammocoetes in Portuguese rivers. Its presence was confirmed in eight distinct independent watersheds: Douro, Esmoriz, Vouga, Mondego, Lis, S. Pedro (a small stream draining to the Atlantic Ocean), Tagus and Sado. Lampetra fluviatilis is thought to be present only in River Tagus. The presence of Lampetra was strongly related with some abiotic predictors (e.g. altitude, lithology, water availability and temperature). A probability of occurrence model was built with the data gathered to be used as a baseline tool to prioritize rivers in terms of their level of importance for the conservation of these species. One of the promising applications of this type of information is the possibility of providing good background information for the selection of watersheds or river stretches as Special Areas for Conservation (SACs) to Lampetra species under the European Union Habitat Directive (Natura 2000), which is the most important legislation regarding the protection of wildlife across Europe.