The decline of eel Anguilla anguilla (L.) in a river catchment of northernSpain 1986-1997. Further evidence for a critical status of eel in Iberian waters

Large-scale surveys by the early 80ies showed that, except in a few coastal streams of northern Spain, the eel Anguilla anguilla (L.) was extinct in > 80 % of the Iberian rivers. A long-term (1986-1997) monitoring of eel abund ance in the River Esva, a small river catchment where the species was abund ant by the mid 80ies, showed a dramatic decline of eel numbers down to the verge of extinction. As inferred by a parallel decline in the commercial ca tches of elvers, no other cause than a reduced recruitment of elvers could be identified as responsible for the decline of the Esva eel. The status of the eel in the Iberian Peninsula is critical.