FishBase 2016: Willem Dekker
Channel: Fishbase Sweden
Date: 2016-12-13

Willem Dekker, Swedish University of Agricultural Sciences (SLU), Sweden, gave a lecture on "OUR EEL STOCK, IS IT SLOWLY DRYING UP?"

Abstract: The eel constitutes the most wide-spread single fish stock in Europe, providing employment to around 10,000 fishers - more than any other fish stock does. The eel is bridging habitats as divergent as the open ocean, high seas and sheltered coasts, large lakes and small ponds, main rivers and smallest streams. Human impacts comprise fisheries, land reclamation, barriers to migration, hydropower killing passing migrants, pollution and many more. Since the mid-1800s, a gradual decline in abundance has been noted (ca. 5% per annum in recent decades). Remedial actions (artificial reproduction, restocking, technical development, etc.) have been pursued for over a century, but without major success. In 1980 (in our lifetime), a steep decline in the number of recruits commenced – their abundance diminishing consistently, by ca. 15% per annum.
Individual fishers and governments have long noticed the on-going decline, but on their own, none of them had any opportunity to reverse the global trend: protection and management of the eel requires a pan-European approach. In 2007, when just 1-10% of the recruits remained, the EU adopted a protection and recovery plan, obliging its Member States to develop national protection plans – a deliberate distribution of control. Recent post-evaluation (2015) now indicates that mitigation measures have been taken all over the continent, but that almost no country has reached the minimal protection needed for recovery. Analyses of the governance process indicates, that the current international scientific advice, which fails to relate to the ongoing protective actions, is a key factor in this impasse – aiming for a conservative, but unattainable data-driven assessment for the whole continent, it does not more than repeating the advice that the eel stock is in a terrible state. Thus, without international
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feedback, the national protection plans have relapsed to uncoordinated and insufficient action. To fulfil the objectives of the European protection-and-recovery plan, a re-focus of the scientific advice on an achievable system of distributed-control is urgently required, enabling feedback on the national protection plans.
The first management actions under the European protection plan were implemented in 2009 – first continent-wide effects, if any, were expected to last at least a year or two. In 2012, an unprecedented rise in the number of recruits was observed all over Europe, which repeated in 2013 and again in 2014, but not in 2015. Though it is too early to credit this surprising trend reversal to the protection plans, it does indicate that there is hope the eel stock can recover – but only if international feedback brings the national management plans to the minimal protection mark.