Is the Eel climbing back up the Slippery Slope?

Last changed: 12 December 2014

Fifty years ago, it was noted that the eel stock was in decline. Fifteen years ago, scientists advised to give the stock immediate protection. Five years ago, the European Union adopted an eel protection plan, which was implemented all across Europe. Now it is time to reflect on what has been done in these five years, what happened after, what has been achieved – and what still needs to be done. Only a few months ago, a large group of scientists at an international eel symposium in Quebec discussed the world-wide situation; see Quebec Declaration 2014. Here, we reflect on the status in Europe, and in Sweden in particular.

Figure 1. The trend in eel landings from the fisheries in Sweden over the past fifty years.
In 2012, the West Coast fishery was closed. Data for inland waters before 1985 are probably incomplete.

In the 1960s, it was reported that eel catches were in decline (Figure 1), and remedial action was taken: fisheries were modernized, young eel were imported and restocked, research was expanded, etcetera. In those years, the developing eel aquaculture in mainland Europe maintained market supply, by growing wild-caught young eels to marketable size in indoor facilities. Now looking back, we can only conclude that all these actions have not been very effective: the stock continued to decline. To make the situation even worse, since 1980 we observed that the number of young eels, recruiting from the sea to our coasts and into the rivers across Europe, rapidly diminished (Figure 2).  Those young eels are most abundant in the Bay of Biscay, but they also occur in the Mediterranean and the North Sea, the

Figure 2. The trend in the numbers of young eels, recruiting to the continent, per year. For North Sea and Atlantic, glass eel is shown. Youngest recruits in Sweden always relates to small yellow eel. Note the logarithmic scale of the vertical axis – on a normal scale, the recent upturn shows as a minor ripple on the bottom.


North Sea, the Skagerrak and the Kattegat. By the time these youngsters arrive from the sea into our rivers, they are already a bit older and larger, from half a year on the Swedish West Coast to several years more in the Baltic. Hence, one would expect the youngsters in Sweden to follow the North Sea trend a few years later – to start their decline a few years after 1980. But we observe the opposite: the Baltic youngsters started to decline long before that happened to the Biscay and North Sea glass eel, more or less in parallel to the trend in our catches. Why? We do not know, but it occurred.

Why has the eel stock declined?

It has taken a long time to recognise what was happening to the eel stock and we still do not know what is the cause: anthropogenic factors or natural variation (ocean climate, global warming?). But even without understanding the problem, the bad state of the stock is enough reason to take protective action, to curtail excessive impacts. Fisheries, water regulating dams blocking rivers, hydropower killing the eel on its way back to the sea and pollution affecting the reproduction – all these factors have their impacts, and all should be addressed.

An eel trapped below a hydropower station. Photo: Watts Brothers.


The European eel - one population

Since the eel in Europe constitutes just one single stock, it would not help very much if individual countries would take protective action. All countries in the European Union share the responsibility for this natural resource. One fish for us all, so all must protect this one shared stock. From Italy and Spain in the south, to Sweden and Finland in the north; from Ireland and Portugal in the west, to Greece and the Baltic States in the east – even the non-EU countries in the Mediterranean should be involved. It requires a huge international approach - in sharp contrast to the local scale in rivers and lakes, where individual fishers practice their profession, and where hydropower generation is having its impacts.

The European protection plan, adopted in 2007, essentially combines that huge international approach with locally adapted action in each country: targets were set for all countries in common, while each country developed its own practical approach in a national Eel Management Plan. That same year, EU decided on an export ban. Since 2009, the trade in eel in or out of the EU is no longer permitted. This ban has stopped the export of thousands of millions of young eels to eastern Asia, where they were grown in aquaculture.

Sweden implemented its Eel Management Plan since 2009. That plan comprises four measures: fishing restrictions, restocking of young eel, reducing hydropower impacts and intensified control. But Sweden is just one of the many countries involved – only if all of them do the right thing, can we expect our shared stock to recover. For some countries in Europe, the plans are quite comparable to ours, but others took quite a different approach. There is no one-size-fits-all solution - but even by different means, countries can achieve the same level of protection.

To the left: A glass eel and a newly pigmented elver. Photo: unknown. To the right: Release of imported young eel,
called: restocking. Photo: Sustainable Eel Group.


What has been done in Sweden?

All in all, the targets of the Eel Management Plan have just been met and mortality is at a level that is considered to be sustainable. The fishery on the West Coast was reduced, and in spring 2012 even completely closed, while the restocking continues there. In inland waters, restocking has increased (to the level that had been applied about ten years ago) and the fishery has been restricted (the recreational fishery on eel was already closed in 2007). To compensate for the impact of hydropower, eel is trapped above hydropower stations and transported to the sea, where they are released. In combination, the restocking, the fishery and the Trap-&-Transport have not achieved the agreed protection level for the inland stock. However, without the restocking, there would hardly be an inland stock; without the fishery, there would be no trapping for transporting; and without the hydropower, there would be no financial basis – a real catch-22 situation. Additionally, the hydropower industry has financed extra restocking on the west coast. Finally, the moderate impact of the east coast fishery has been restricted a bit further – but this fishery targets predominantly the eel passing our coast on their way from other Baltic countries towards the Atlantic Ocean, and coordination with those other Baltic countries has as yet not been achieved. 

In the other countries, results are quite variable; some have achieved major protection, while others have taken only little action or have not reported anything they have done (Figure 3). We do not spell out details for all those other countries here, but note that – for the whole of all reporting countries – the protection level is still below what was agreed in the European eel protection plan.

Figure 3. Status of the eel stock across its distribution area. For all countries/areas, the 2011 indicators are shown, as reported in 2012. The Swedish West Coast fishery, however, was closed in 2012 (for 2012, the red bubble would have been plotted in orange). For France, the national total is shown (big, transparent red), as well as the different areas (no indices reported). The size of each bubble is proportional to the importance of each area. Bubbles in green have a healthy stock; the red ones are insufficiently protecting a depleted stock; and the orange ones are adequately protecting a still depleted stock.
For countries/areas where no information is available, a  is shown. See the original report (WGEEL 2013, p. 36) for further details.


Believe it or not, but only two years after the implementation of the Eel Regulation, the trends in the young eel recruitment is showing a major upturn! For a couple of years in a row now, immigrating numbers have increased (Figure 2), and the stock on our West Coast shows a remarkably rapid recovery too. After thirty years of decline, the tide seems to have turned. Whether or not that is due to the protection plans is hard to tell. It could as well just be an unrelated change in ocean conditions, or only a temporary hick-up. After all, the achievements all over Europe have by far not reached the minimal protection yet. But whatever the cause, the current upward trends do give hope for the future.

It has been suggested that this upturn in recruitment indicates that fishing restrictions across Europe can be lifted. The actual numbers, however, are still only 5-10% of the good old days, and protection levels in many countries are still far below a sustainable level. As hopeful as this upturn might be, it gives the more reason to protect them well.  And the more reason to reach the agreed level of protection in all areas and countries where it has not been achieved yet.

Willem Dekker, Håkan Wickström and Jan Andersson, SLU, Department of Aquatic Resources.

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