Analysis of the eel management plan by the Swedish Institute for the Marine Environment identifies clear shortcomings. It is unlikely that Sweden will meet the target that has been set for silver eels capable of migrating back to the Sargasso Sea so that they can contribute to regeneration.
The recruitment of new annual cohorts of European eel has decreased over a long period, and today it represents only a few per cent of what it was 30 to 50 years ago. The eel is particularly sensitive to overfishing, as it becomes sexually mature at an advanced age, but there also other reasons for its decline. The International Council for the Exploration of the Sea (ICES) has long warned of the consequences of the ongoing population decline, and since 1998 the Council has recommended that an eel management plan should be adopted at the European level. Since 2007, the European Commission has also required all eel-fishing Member States to develop a plan to reduce eel mortality caused by human activity. In Sweden, the Swedish Board of Fisheries has been tasked by the Government with taking responsibility for a national eel management plan.
Many measures are listed under the plan: prohibition of recreational fishing for eel, special professional fishing licences for eel, modified fishing times, closure of yellow eel fishing on the west coast and increased stockings of juvenile eels. There is also a declaration of intent by the Swedish Board of Fisheries together with six power companies to reduce mortality due to eels being sucked into the turbines of hydropower plants.
The analysis of the Swedish eel management plan by the Swedish Institute for the Marine Environment identifies a number of shortcomings. Some of these are listed below:
• There is a clear conflict between conserving the eel as a species and preserving the eel fishery. The management is aimed at “mitigating” the adverse effects of eel fishery and other human activity instead of guaranteeing that the conservation target is met. By comparison, both Norway and Ireland have introduced a complete suspension of all eel fishery so that migration back to the Sargasso Sea will increase.
• The material on which the plan is based is deficient and lacks critical scrutiny. There is uncertainty in stock assessment which has not been taken into account. There is therefore a great risk of overestimating the size of the stock and continuing to over-exploit.
• The operationalisation of targets as requirements and measures is inadequate – the gains considered to be made from stockings, fishery regulation and reduced turbine mortality are based more on hope than on solid data. Implementation of the plan takes place or is intended to take place over a very long period of time. Even if the plan is eventually followed, it is unlikely that 2.6 million silver eels will be able to migrate, which is Sweden’s target.
This is due among other things to relatively extensive eel fishery still being permitted and uncertain results from the stocking of Swedish waters with French and British juvenile eels; the eel may be disoriented and it is doubtful whether it will find its way back to the Sargasso Sea to spawn.
Contact at the Swedish Institute for the Marine Environment: Henrik Svedäng, docent in marine biology at the University of Gothenburg. firstname.lastname@example.org +46 (0)31 7866 645, +46 (0)70 3536 804
Helena Aaberg | idw
A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
18.08.2017 | Life Sciences
18.08.2017 | Physics and Astronomy
18.08.2017 | Materials Sciences