Common otter (Lutra lutra)
Source: H Ausloos, WWF
Otters live in fresh, brackish, and even salt water habitats of rivers, streams, lakes, canals, open marshes and coasts. In mountain areas they have been observed up to 2800 m. Otters are carnivores, feeding mainly on fish, amphibians and crustaceans, but also, to a lesser extent, on waterfowl, mammals and reptiles. They are mostly active at night which makes them difficult to study. Over the last three decades, their populations have declined dramatically in many Western and Central European countries. In the past otters were killed for their fur and also for perceived damage to fisheries. Current threats include habitat destruction by drainage of wetlands, river regulation, clearance of vegetation cover from river banks, and dam building. In poor habitats, disturbance by recreational activities may be detrimental, but the most important factor is water pollution. Research results suggest that contamination of fish prey by bioaccumulating organochlorine pollutants both pesticides and polychlorinated biphenyls (PCBs) was the major cause of decline (Mason and O'Sullivan, 1992). Because of their sensitivity to environmental stresses, otters can be considered as biological indicators for the quality of a wetland habitat, otter presence indicating good environmental conditions. Hence, the disappearance of the otter in many European regions reflects quite precisely the scale of environmental damage to which many wetlands have been exposed during the last decades. Today, there are many attempts to reintroduce the otter an undertaking that can be successful only if the quality of the habitat has been improved accordingly.
Map 9.12 - Distribution of the common otter (Lutra lutra)
Source: Council of Europe, 1992a
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