Eels Close to Extinction!!

[tony jolley]

I just did a quick search through my data and found a couple of things of intreast.

 

One is below and a couple of links to look at,

 

Narrow Sargasso Sea

When eels reach their spawning grounds, they tend to choose a mate from their home region.

22 February 2001

JOHN WHITFIELD

 

Ever been to a party and clung doggedly to the one person there you already knew? Eels are like that. They converge on the Sargasso Sea from all over Europe and North Africa -- but rather than mingle, they tend to breed with other eels from their home region, researchers have discovered1.

 

Since the 1920s, it has been thought that European eels (Anguilla anguilla) from across the continent had a mating free-for-all, or 'panmixia', says Thierry Wirth, one of the new report's co-authors. And this idea was supported by data from proteins and DNA that showed no strong differences between populations from different areas.

 

But Wirth, along with Louis Bernatchez, his colleague at the Université Laval in Quebec, subjected these slippery customers to a more sensitive genetic analysis. They homed in on stretches of DNA known as 'microsatellites', where short sequences two to four letters long are repeated many times over (for example, …ACTACTACT…).

 

The length of microsatellites varies very widely between individuals, as the cell's machinery often loses count when copying and aligning such monotonous sequence. This makes them ideal for genetic fingerprinting.

 

Microsatellites from 611 eels migrating out of rivers that flow into the Mediterranean, Atlantic, Baltic and North Sea pinpointed where the eel had come from. What's more, the size of the genetic difference between two mating eels reflected the geographic distance between their homes.

 

Wirth and Bernatchez suggest that the most likely explanation for the genetic similarity between mating eels is down to timing. Eels from different areas arrive in the Sargasso Sea at different times and breed with whoever happens to be around and willing -- most probably eels from the same region.

 

"This result is not that surprising, but it is very important," says Simon Archer, a biologist at the University of Surrey in Guildford, UK, who has studied eel population genetics. "Many researchers have suspected that perhaps multiple breeding groups or grounds exist within or in addition to the Sargasso Sea." Archer says it's possible that Mediterranean eels, for example, may be breeding in their home sea, as large numbers have never been seen migrating through the Straits of Gibraltar.

 

Mating with locals might keep genes that are adapted to living in, or navigating to, a certain place together. One possibility, says Wirth, is that different eel populations have genetic clocks set to trigger migration or reproduction at different times.

 

The eel's life cycle takes it from sea water to fresh water and back again. Born in the Sargasso Sea -- an area of the Atlantic between the West Indies and the Azores, bounded by ocean currents rather than land -- the fry ride the Gulf Stream back across the Atlantic, and spend up to two years in coastal waters. They then metamorphose into elvers and swim upriver, where they spend the next 10-15 years before migrating back to the Sargasso to spawn and die.

 

The discovery of genetic isolation has added to eels' mystery, as it suggests that youngsters can find their way back to their parents' home, even though they have never been there.

 

 

http://europa.eu.int/comm/fisheries/news_c...inf03_40_en.htm

 

http://www.fishbiology.net/stw.html

 

http://www.iol.co.za/index.php?click_id=31...40B261&set_id=1

 

http://www.stw.nl/projecten/L/lbi4199.html

[My-insane_M8]

so far i've been unable to access the news story you posted? However, i'm aware of this problem will the eel population, and agree it needs to be addressed. However, sadly i think its all far too late. Eel's travel via our network of streams and rivers before they reach a lake, and that's the problem, every winter & spring time we see on the news peolple being flooded out of their homes, due to rivers bursting their banks. they say its golbal warming? yeah my arse, i call it bad construction, they block or try to divert these small stream's and they either do it badly, or not at all. So until this is sorted, things will get worse. When will they learn, you won't beat mother nature. Mum knows best!

I hope all that makes sence? Please take into account i am insane!

Dale.

[trent.barbeler]

Dear Phil,

 

Crikey. You know some stuff.

 

What I'd like to know please, is what type of commercial fishing there is out in the Sargasso sea? Especially like to know what type of commercial fishing undertaken in the Sargasso at the same time European Eels spawn there. By-catches. By-catch to what specific species?

 

When "do" European eels spawn in the Sargasso sea by the way?

 

Personally Phil, I thought and think, that £1000 per annum is way way over the top for data based information. Almost everything these people provide is available for free elsewhere anyway.

 

Dear Tony,

 

Good posts. Keep up the good work.

 

Regards,

 

Lee.

[Peter Waller]

Dear Insane, good to see a tad of sanity out there in cyberspace.

[tony jolley]

My-insane_M8:

so far i've been unable to access the news story you posted? However, i'm aware of this problem will the eel population, and agree it needs to be addressed. However, sadly i think its all far too late. Eel's travel via our network of streams and rivers before they reach a lake, and that's the problem, every winter & spring time we see on the news peolple being flooded out of their homes, due to rivers bursting their banks. they say its golbal warming? yeah my arse, i call it bad construction, they block or try to divert these small stream's and they either do it badly, or not at all. So until this is sorted, things will get worse. When will they learn, you won't beat mother nature. Mum knows best!

I hope all that makes sence? Please take into account i am insane!

Dale.

I thought I`d post the complete article for anyone who couldn`t read it all.

See below.

http://news.independent.co.uk/world/enviro...sp?story=468580

 

 

Eels face extinction as numbers drop by 99 per cent in 20 years

 

 

Fishing ban proposed as populations across Europe suffer dramatic decline in stocks

 

By Severin Carrell

 

30 November 2003

 

 

Tough new powers to save the eel from a catastrophic slump in numbers are to be introduced after experts warned that the European eel is facing extinction. Biologists warned last month that European eel populations could be as low as one per cent of the size they were 20 years ago. It is one of the most severe and puzzling slumps in any fish species seen by conservationists.

 

To halt that decline, ministers are planning to introduce tough measures, which will include new powers to ban eel fishing, outlaw unlicensed fishing and set tight rules stopping the use of unsuitable nets on the country's rivers.

 

The initiative, which is expected to get official approval within weeks, follows alarming evidence from marine conservationists that native populations across Europe are in crisis.

 

Over the past 10 years, the number caught across Europe has slumped by two-thirds - from about 30,000 tons to 10,000 tons. Around the Severn Estuary - Britain's largest eel fishery - the rate of decline is even steeper, falling from about 50 tons in the 1980s to just 10 tons last year.

 

The International Convention on the Exploitation of the Sea (Ices) repeated warnings that numbers have fallen so low that its population is now "outside safe biological limits".

 

Experts are at a loss to explain what has gone wrong, but they suspect the decline can be blamed on over-fishing, changes in ocean circulation, water pollution, the construction of dams, power stations and weirs on rivers, and even a vicious parasite carried by Asian eels, which damages its buoyancy sacs.

 

The scale of the crisis has lead the European Commission to call for an urgent programme of emergency action across the continent. In its latest report, the commission warned that if the crisis worsens, it could ask for an outright ban on all eel fishing to allow stocks to recover.

 

The European eel has been caught in a dangerous paradox, its report said. As their numbers have slumped, their sale price has leapt upwards, making them even more valuable for commercial fishermen and poachers. Young eel, known as glass eels or elvers, are caught by the ton for eel farms, but they are also used to restock rivers and lakes such as Lough Neagh in Northern Ireland, where populations have slumped.

 

But the price for elvers is now so high that experts at the Environment Agency, respon- sible for protecting English rivers and estuaries, fear they cannot afford to buy enough elvers to restock depleted areas. In 1998, the price of elvers reached £250 per kilo.

 

"Due to the high price of eels, there are strong economic incentives to continue fishing down to the last few recruits," the commission said.

 

The crisis is worsened because adult eels live for up to 15 years before going back to sea to mate and spawn, so eel populations can take several decades to rebuild. "This means that the eel stock is in an extremely high-risk situation," it added.

 

Miran Aprahamiam, an eel expert with the Environment Agency, said: "This is a long- term project. They've such a long life, we aren't going to see the real benefits for 10, 15 or 20 years. This isn't going to be short-term."

 

The commission is urging EU member states to introduce even tougher proposals than those planned by the Department of the Environment, Food and Rural Affairs. They include limits on catch sizes, bans on catching elvers, seasonal or regional bans on fisheries and licensing of all eel fishing.

 

But, in a measure that alarms anglers, it also wants an emergency ban on fishing for silver eels - the adult eels that produce new young at sea. "The present situation is sufficiently disquieting that exploitation of eels should be reduced to the lowest possible level while a recovery plan is being formulated," the report warned.

 

However, Clive Dennison, general secretary of the Eel Study Group, said this was unfair. Large-scale illegal fisheries, using so-called "fyke" nets, were a major factor in the decline, he insisted. Mr Dennison welcomed the Government crackdown, but said ministers also needed to make possessing unlicensed nets a criminal offence. "We need to give the Environment Agency the power to restrict the pressure on eel fisheries," he said.

['eelfisher']

Dear Phil

 

Just to let you know that I will be coming back with a small post regarding what the real picture was with my taking your quote and commenting on it on this thread....I have just been too busy sorting other stuff out but should find time tomorrow.

 

Yours With Respect.....

Steve.

 

PS....Thanks for the chat tonight Anthony...always good to talk.....and I shall also second the thoughts above...very good posts on here by you as usual, including posting the full article so others can read it through.....nice thinking.

[Chief Trottinfloats]

Mr Hacketts words;;

 

"P.s. and if you really live where you indicate in another thread, you'll know about the Greenland Cod."

 

Which Greenland area Mr Hackett?

 

A short story which may interest one as you so highly qualified in? Oceanic Studies?

 

Whilst a large fishing vessel was cutting through the ice around Greenland, the skipper noticed a mysterious object in the sea off towards the Northern horizon. Curious as to what the object could be, the skipper headed off in its direction for a closer look.

 

When the fishing boat got closer, the object appeared to pull up a net loaded with cod and quickly ascended up into the sky and over the horizon. Later that same week, another fishing vessel reported seeing something very similar. Upon steaming closer to the object in the water, the entire crew observed that the object appeared to be Santa Claus. Fishing!

 

After a hearty "ho ho ho", he pulled up his net, teeming with codfish and yelled, "Off to the North Pole".

 

Seems like with the cod shortage, Santa is trying to get on some of the action, although it seems like there is no record of Santa buying quota. Perhaps he is rolling the dice, fishing illegally, before preparing for his holiday duties!

 

I suppose we will find out if some receive cod under the tree.

 

We will talk some more I'm sure Mr Hackett. Must go as I have to brief a committee up on the hill about something,.. Fishy

 

Merry Christmas.

[Peter Waller]

The above is a tad deep for the lesser mortals who inhabit AnglersNet, but I think it could brighten up a cold, dull evening. Carry on folks, next episode please !!

[phil hackett]

Chief Trottinfloats:

Mr Hacketts words;;

 

"P.s. and if you really live where you indicate in another thread, you'll know about the Greenland Cod."

 

Which Greenland area Mr Hackett?

 

A short story which may interest one as you so highly qualified in? Oceanic Studies?

 

Whilst a large fishing vessel was cutting through the ice around Greenland, the skipper noticed a mysterious object in the sea off towards the Northern horizon. Curious as to what the object could be, the skipper headed off in its direction for a closer look.

 

When the fishing boat got closer, the object appeared to pull up a net loaded with cod and quickly ascended up into the sky and over the horizon. Later that same week, another fishing vessel reported seeing something very similar. Upon steaming closer to the object in the water, the entire crew observed that the object appeared to be Santa Claus. Fishing!

 

After a hearty "ho ho ho", he pulled up his net, teeming with codfish and yelled, "Off to the North Pole".

 

Seems like with the cod shortage, Santa is trying to get on some of the action, although it seems like there is no record of Santa buying quota. Perhaps he is rolling the dice, fishing illegally, before preparing for his holiday duties!

 

I suppose we will find out if some receive cod under the tree.

 

We will talk some more I'm sure Mr Hackett. Must go as I have to brief a committee up on the hill about something,.. Fishy

 

Merry Christmas.

Me thinks the Chief has been Flushed from his tepee and the wood into the Shires

[phil hackett]

quote:

---

Originally posted by trent.barbeler:

 

Personally Phil, I thought and think, that £1000 per annum is way way over the top for data based information. Almost everything these people provide is available for free elsewhere anyway.

 

 

Regards,

 

Lee. [/QB]

---

Lee whilst not wanting to defend the price BIDS charges as its outrageous, the service it provides when researching is second to none. By putting in key words regarding the topic you are researching, it will list every peer reviewed scientific paper ever written anywhere in the world, over the last 25 years on that subject matter. You also get the abstract of the paper and the journal it appeared.

 

This is important when you’re up against time constraints, as the abstract tells you what the papers about, what the author(s) found or didn’t, as the case may be and their conclusions in brief.

If what you find in the abstract is of use to you in your research, you can then quite easily go and find that paper in the journal(s) stated, in the British Library, and/or request it of them, at a price. The time BTW for BL getting a paper to you is about 3-6 weeks. You can also use the better City libraries but the journals they keep tend to be limited for cost reasons. University libraries are not generally open to the public, but are very useful if you can gain access to them. I’m fortunate that I can at times get access to the three in my area. However, that access is limited now, to friends pulling a few strings for me. To access BIDS you need a current student library card, which I haven’t had for some years. The growth of the internet has opened up newer avenues for researchers but there are two major problems with it. 1) There’s lots of rubbish and quasi-scientific papers kicking about on it.

2) Good scientific journals still don’t allow you access to them unless you pay an access fee per year. This can range from £50-200, and there’s no point in this if you just want access to read one paper. A very costly way of doing thing, when you consider there’s about 100-150 journals published worldwide in the biological and environmental field alone.

 

For the pedantic amongst you, by good scientific journals, I mean ones that will not publish papers that have not been scrutinised at ever stage of the process - conception, experimental design, research, methodology, results, discussion and conclusion(s) by review for flaws anywhere in it.

 

Yes Lee you are right that the information is out there somewhere, but how long would it take you to find it all without a service like BIDS? That I’m convinced is why they can charge the prices they do for their services. They have a unique fast tool for researchers, and they bloody know it. And boy will they make you pay for it, handsomely!