small aquacultural pondwith waterfall in austria

agriculture alpestris aquacultural aquaculture aquafarming aquatic austria austrian beam behavior biodiversity boulder breeding brook brown clear conservation countryside culture diversity dynamics ecological ecology ecosystem environment farm farming fish fisheries fishery fishing fishpond freshwater habitat harvesting health hill industry landscape life local maintenance management mountain native natural observations pond ponds population practices production productivity projects rainbow rearing recreational research resource resources rural salmonid salvenius scenery small spawning species stocking strategies stream summer sun sunrise sustainability sustainable trout underwater waterfall wildlife