Rivers in search of the European eel. Distribution and threats of the Critically Endangered Anguilla anguilla (Linnaeus, 1758) in Sicily: the province of Ragusa as a case study

Duchi A.

Published date: January 2021
Volume: 45
Number: 1
Pagination: 031-037
doi: https://doi.org/10.26028/cybium/2021-451-003
Notes:

How to cite: Duchi, A. (2021). Rivers in search of the European eel. Distribution and threats of the Critically Endangered Anguilla anguilla (Linnaeus, 1758) in Sicily: the province of Ragusa as a case study. Cybium, 45(1): 31-37. https://doi.org/10.26028/CYBIUM/2021-451-003

Abstract

The European eel is listed as Critically Endangered (IUCN). Unfortunately, there are still data gaps to be filled, particularly in its southern range of distribution. An accurate and more complete risk assessment is extremely important, since threats and their relative importance can differ in various territories. In Sicily, eel was historically present and it was the principal caught species in the inland hydrosystem. However, there has been no updated assessment of its presence and threats. The objective of this study is to fill in the information gap, while focusing on the South-Eastern Ragusa province, the area with the most available data. The species was found in six river basins out of seven, but only in less than half of the watercourses and sampled sites. In some rivers, it was found at the river mouth only. More than two-thirds of the river network has shown to be devoid of eels. Various threats were found: unpassable barriers, extreme drought, channelization and poaching. Pollution, albeit present, seems to be least dangerous, excluding very heavy organic pollution or chemical spills. However, there are no data regarding the bioaccumulation of contaminants. Moreover, angling seems to have low impact in the area. A conservation and management plan for the species in Sicily is urgently needed and should primarily include: improving of the river continuity, restoration of the aquatic environments and of their watersheds, and sustainable use of water resources. It is also essential to implement anti-poaching activities. Finally, the sources of pollution must be eliminated. As has occurred in other countries, the European eel can become an umbrella species, whose restoration would prove to be positive for the entire Sicilian hydrosystem.

Keywords: Anguilla - Channelization - Conservation - Drought - Poaching - Pollution - Restoration - Sicily
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