European eel found to spawn across 2000 km wide region of the North Atlantic Ocean

APRIL 30, 2019 REPORT

by Bob Yirka , Phys.org

A team of researchers with members from Japan, Sweden, Denmark and Germany has found evidence showing that European eel spawn across a 2000 km wide region of the North Atlantic Ocean. In their paper published in the journal Biology Letters, the group describes their study of recently hatched eel larvae in the North Atlantic Ocean, and what they found.

Almost a hundred years ago, scientists discovered that European eels have a unique lifestyle—one that includes spawning in the Sargasso Sea, which is approximately 5000 to 7000 kilometers from where they live as juveniles and adults in European and North African rivers. But the extent of their spawning has never been pinned down. The researchers note also that the number of European eels has been dropping dramatically since the 1970s, and nobody knows why. The current population is believed to be approximately 5 percent of what it once was. In this new effort, the researchers used multiple ships to survey large parts of the North Atlantic Ocean from approximately 70°W to 50°W—to learn more about the spawning habits of the endangered eel.

The Sargasso Sea is actually an area entirely within the North Atlantic Ocean, just off the east coast of the United States—it is the only sea in the world that has no land boundaries. It became singled out as voyagers discovered it was bounded by four ocean currents that form a gyre. It was named for the Sargassum seaweed that grows in abundance there. Prior research has shown the area to be mostly free of geographical formations—its bottom is mostly flat. The area is known for its marine plants and for its deep blue hue.

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Eel patrol: Tracking down poachers with the wildlife police

21 April 2017

Fishing for the endangered European eel is allowed only under strict rules. Clare Wilson joins the environmental officers patrolling the banks of the UK’s River Severn

It’s a cold clear night and the River Severn is sparkling under a full moon. Tonight, I’m on eel patrol – out with staff from the UK’s Environment Agency on the watch for illegal fishing of the critically endangered European eel.

This mysterious creature with a mind-boggling life cycle has crashed in numbers by 95 per cent in the past three decades.

European eels spend most of their lives lurking in muddy rivers. At about 10 years old, they swim thousands of kilometres out to the ocean, until they reach the Sargasso Sea in the western Atlantic. There they spawn – and die.

Their tiny offspring then make the opposite journey. The Gulf Stream sweeps them to the mouths of European rivers and during the large spring tides the young elvers, about the size of an earthworm, come swarming up the waterways.

The Severn gets a large share because of its prime location facing the Atlantic Ocean and the huge funnel shape of its estuary. They once came in such numbers locals would catch them in pillow cases and hold elver-eating contests. They are supposed to be tipped into a hot frying pan still live and wriggling, in recipes such as elvers with eggs and bacon.

Now elver fishing is only allowed on a few rivers and under strict rules: the “elvermen” must use dip nets below a certain size. And, they can sell only to licensed dealers who must then send 60 per cent for restocking less favoured rivers, with the rest going to aquafarms and restaurants in Europe.

Then there’s the black market, in which elvers are illegally exported to meet demand in China and Japan. Last month, a batch of 600,000 live elvers was found at London Heathrow Airport in a container headed for Hong Kong. That batch probably came from France, but the illegal trade goes on in the UK too, says Chris Bainger at the Environment Agency.



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95% population decline in European eels spurs tracking research – more news

By attaching satellite and data storage tags to about 600 eels from different places in Europe the project scientists were hoping to map the route of the spawning eels.

Eels tagged to help scientists understand migration

January 2013. Nobody knows the underlying biological mechanisms of the European eel's migration. Thanks to an EU-funded research project called eeliad, now about to reach completion, biologists have revealed some of its secrets, including a better understanding of its biology and migration route.

All European eels living from Northern Africa to Iceland are believed to migrate thousands of kilometres to the Sargasso Sea (The Sargasso Sea lies in the middle of the North Atlantic) to spawn. Findings of newly-hatched eel larvae in the Sargasso Sea strongly support this theory. But no eggs or adult eels have ever been caught in the area.

600 eels tagged
By attaching satellite and data storage tags to about 600 eels from different places in Europe the project scientists were hoping to map the route of the spawning eels. "We could track the satellite tags as far away as the Azores. This suggests that the eels take a different route to the Sargasso Sea than previously thought. It seems as if they're saving energy by hitching a ride on the Azores Current," Kim Aarestrup tells youris.com. He is a senior scientist at the Technical University of Denmark (DTU), in Silkeborg and one of the leading researchers behind the satellite tagging.

"Very little is known of the oceanic part of the eel's life history," says Martin Castonguay, an eel expert and research scientist at The Maurice Lamontagne Institute in Mont-Joli, Canada, adding: "The most important thing the eeliad project provided is that it gave us the first observations of adult eel migrations in the open Atlantic Ocean for distances up to 1,300 km from the release point." Although he has not been a part of the project, Castonguay believes it has been "very successful".

Among other things the project scientists also tested the spawning ecology of the eels by using genetic research, combined with a fisheries biology technique for tracking fish movement called otolith microchemistryand modelling methods. The analyses were undertaken both on eel larvae collected in the Sargasso Sea and on glass eels collected from the coastline of Europe and North Africa. "Our genetic research showed that the eels living all across Europe mate randomly. This is very unusual for animals that are so widely distributed. It strongly indicates that the European eels are spawning in the Sargasso Sea and nowhere else," says Thomas Dammals, a research scientist at DTU who was involved with the genetic research in the project.

Continued:  http://www.wildlifeextra.com/go/news/eel-migration.html

Eel trade ban extended until end of 2011

THE European Commission decided on December 6 to extend the temporary import and export ban on European eels.


The Committee on Trade in Wild Flora and Fauna, assisting the Commission in implementing the Convention on Trade in Endangered Species of Wild Fauna and Flora, CITES, concluded to extend the ban of export and import of European eels following the unanimous recommendation from its scientific advisory body, the Scientific Review Group.

This ban will stay in place until the Scientific Review Group reassesses the situation at the end of 2011. However, both the Chair of the Scientific Review Group and the representative of DG Mare pointed out that the eel stock is very unlikely to recover until then.

The meeting also discussed the option of upgrading the European eel on the CITES annexes, from annex B to annex A, which would give increased protection. No decision was taken, but it will continue to be discussed with both fisheries and CITES administrations during 2011.

The summary from the meeting can be found here.

http://www.fishnewseu.com/latest-news/world/4965-eel-trade-ban-extended-until-end-of-2011.html

Action to be taken to stop Sussex’s plummeting eel population

The Environment Agency is consulting on a series of measures designed to stop the decline of eels in Sussex, as populations in the region are plummeting and they are now at their lowest since records began.

The Environment Agency is consulting on a series of measures designed to stop the decline of eels in Sussex, as populations in the region are plummeting and they are now at their lowest since records began.

Once common in British waters, the long-term future the traditional sea-side delicacy is bleak as the numbers of eels entering European rivers has crashed by over 95 percent in recent decades.
The decline is thought to be caused by a number of factors including fishing and changes to the habitats adult eels depend on and to the rivers they use for migrating to and from the sea. Their survival may also be affected by changes in ocean currents and temperatures which may be linked to climate change

In an effort to stop the complete disappearance of eels in English waters the Environment Agency is considering introducing tighter restrictions on fishing for mature eels and young ones, known as elvers. The new proposals include:
• banning trawling for eel and elver
• introducing elver and adult eel close fishing seasons
• stopping the expansion of adult eel fisheries
• prohibiting net fishing at locations where elvers are particularly vulnerable;
• specifying what fishing equipment and methods can be used to catch elvers;

The proposals are part of a host of measures to reverse the eels decline. Locally, the Environment Agency works to make migration through rivers and wetlands easier by installing fish passes, they have also been going on patrols to stop poachers and improving availability of good quality habitat for eels.

Fisheries Technical Specialist for Environment Agency, Charles Bacchus, said: “Given the critical state of our eel stocks we want as many anglers, net fishers and others with an interest in eel fishing and conservation to share their views with us.

“Young eels used to hatch at sea and swim up English rivers in huge shoals so dense they could turn the riverside margins black. However, if eel population numbers don’t improve soon we could reach a critical point of no return, and could face the end of this species in our waters and possibly extinction.”

Anyone can take part in this consultation which runs for 12 weeks, closing on 7 September 2009.Details of these proposals are available from the consultation section at www.environment-agency.gov.uk

• Eels have a long-range lifecycle. They spawn in the ocean and their transparent larvae drift on ocean currents until they reach the continental shelf. As they approach the coast, they grow and take on a darker colour. Now called elvers, they enter estuaries and migrate upstream to grown and mature in rivers, lakes, ponds and wetlands as yellow eels. They can remain in freshwater for over 20 (and up to 40) years, before migrating downstream, taking on a silver appearance, to the sea. The mature adults are thought to migrate back to the mid-Atlantic to spawn. Truly one of nature’s great migrants.

• Eel are important to the diet of several other rare and protected species, such as otters and bittern.

• Eels are listed as endangered by the Convention on International Trade in Endangered Species.

http://www.environment-agency.gov.uk/news/109390.aspx?lang=_e

Norway helps endangered eel wriggle from fish nets

Oslo, Norway – Norwegian fisheries regulators in a landmark decision have banned all fishing of the critically endangered European eel starting in 2010 and cut 2009 catch quotas by 80 percent.

The Norwegian Ministry of Fisheries also has announced that all recreational fishing of European eels would stop on July 1st, as stock of the eels hit historically low levels and continue to decline.

The decision represents a major conservation decision that is a model for proper fisheries management, according to WWF-Norway.“The Minister of Fisheries is making an important, and the only right choice, and is showing international leadership in fisheries management,” said Rasmus Hansson, WWF-Norway CEO.

“Norway’s Fisheries Minister, Helga Pedersen, has used every occasion to point out that Norway is the best in the world on fisheries management, and by making bold moves like this they have probably earned the title.”

The European eel is listed as critically endangered in Norway and on the IUCN Redlist. Stocks are at historically low levels with spawning levels at between one and five percent from their 1970 level, with only the Atlantic area seeing higher levels. In the Baltic Sea, including Kattegat and Skagerrak, indices show a sharp decline in young yellow eel stocks since 1950.

As early as 1999, The International Council for the Exploration of the Seas (ICES) stated that the eel stock was outside safe biological limits, and that the fishery was unsustainable. Yet, fishing has been ongoing for decades, despite scientific advice. “A total fishing ban is the strongest measure the fisheries management can use, and when a species is critically endangered one must use the strongest and most efficient measures. This protection should have been implemented many years ago, and we are hoping that the long-overdue protection is not too late,” Hansson said.

A successful rebuilding strategy for the eel, both in Norway and the EU, will have a substantial impact on eel numbers in Norwegian waters. Consequently, Norway has a great responsibility in influencing both the management and the research that is being undertaken in Europe. In Europe, fishing for eel continues, despite the very severe and depleted state of the stock.

“WWF urges Ms Pedersen to fight for the EU taking similar bold measures in their fisheries management, and WWF will fight to stop the eel fishery in the EU,” Hansson said.

http://www.panda.org/wwf_news/news/?168882/Norway-helps-endangered-eel-wriggle-from-fish-nets