The European eel quality database: towards a pan-European monitoring of eel quality

Abstract

The stocks of the European eel Anguilla anguilla are in decline and there is an increasing awareness that poor health status due to contaminants and/or diseases might be a key element in this decline and might be a hindrance to recovery. Many countries have started compiling data on the health status of eels in their water bodies. Objectives for these monitoring actions are diverse and there is a large amount of information collected by EU member countries. However, this information is widely scattered over Europe in agencies, institutes or universities. As there is a growing need to collect and report on data on the health status of the eel on international level, the Joint EIFAC/ICES Working Group on Eels initi- Eel Quality Database to collect recent data of contaminants and diseases over the distribution area of the eel. This paper describes the aim, the set up and future development of the database in order to give it greater publicity and to call on scientists or managers to submit data on eel health status. The database represents now the first comprehensive pan-European compilation of eel health data, including data from over 10,000 eels from approximately 1,200 sites over 14 countries. Preliminary work has indicated a number of shortcomings and future developments will be needed. Guaranteeing further development of the database, harmonisation of methods, quality assurance, and setting up harmonised eel monitoring strategies over Europe will be a great challenge and will need pan-European cooperative work.

Reproductive potential of silver European eels (Anguilla anguilla) migrating from Vistonis Lake (Northern Aegean Sea, Greece)

“…ICES 2006; Belpaire et al, 2011;Marohn et al, 2013;Amilhat et al, 2014). Consequently, researchers are investigating various components of this complex topic, but data from the eastern Mediterranean part of the species range is extremely limited.…”

“…Regional conservation actions can be prioritised by identifying areas of high spawner quality (Belpaire et al, 2011). Despite the possible negative effects of A. crassus, silver eels from Vistonis Lake in Greece could be important contributors to the spawning stock; the female dominated sex ratio, large body size and high fecundity are indicative of the reproductive potential of the lake's silver eels.…”

“…These include, for example, infection by the swimbladder nematode Anguillicola crassus, bioaccumulation of lipophilic contaminants, and insufficient energy reserves (see Belpaire et al, 2011). Hence, the investigation of 'spawner quality' (according to ICES (2006): "the capacity of silver eels to reach spawning areas and to produce viable offspring") has become an important research topic.…”

“…MacNamara & McCarthy, 2012;Marohn et al, 2013;Quadroni et al, 2013;Amilhat et al, 2014). The eastern Mediterranean (defined here as east of 20° E) is distinctly under-represented, even in 'pan-European' type studies (Jakob et al, 2009;Belpaire et al, 2011). Eel fisheries data is limited for this region (Dekker, 2003), andavail-, 2003), and avail-2003), and available biological data (from Greece, Former Yugoslav Republic of Macedonia, Turkey, Israel and Egypt) generally relates to the glass and yellow eel life-stages (see e.g.…”

Contamination, parasitism and condition of Anguilla anguilla in three Italian stocks

“…Besides a reduction in spawner abundance caused by overfishing and habitat loss, an additional driver of eel collapse could be a reduction in spawner quality due to infections by viruses and parasites and pollution by inorganic and organic chemicals (Belpaire et al 2011a). The exotic nematode Anguillicoloides crassus can cause swim bladder dysfunction and thus influence the migration of mature eels (Möller et al 1991;Sjoberg et al 2009).…”