grayling fishing

twin_beacon

Zzippy wrote: »

Weirs have been on rivers for hundreds of years, and do not prevent elvers from migrating upstream. I'm guessing you've never watched elvers wriggling up moss-covered vertical surfaces to get past obstacles like weirs and waterfalls. The reason eels have declined so much is in the marine environment, we simply don't know why, but the numbers of glass eels and elvers entering our freshwater environment has crashed over the last 25 years, in spite of healthy runs of silver eels migrating to spawn for much of that period. Hard to know what we can do to boost eel stocks when we don't know why they aren't surviving at sea. Electro-fishing dace out of the Blackwater would be physically impossible BTW.

I thought it was some parasite that attacked the elvers that caused their loss in numbers, im not sure if that was ever confirmed though. The future does seem a bit brighter for the eel though, numbers returning have been increasing in the UK in the last few years. http://www.theguardian.com/environment/2014/jan/14/european-eels-record-third-year

im afraid the dace are there to stay, once a species has a few successful spawning seasons, its impossible remove them, you might get a lot of the adult fish, but you wont get the fry.

Zzippy

twin_beacon wrote: »

I thought it was some parasite that attacked the elvers that caused their loss in numbers, im not sure if that was ever confirmed though. The future does seem a bit brighter for the eel though, numbers returning have been increasing in the UK in the last few years. http://www.theguardian.com/environment/2014/jan/14/european-eels-record-third-year

im afraid the dace are there to stay, once a species has a few successful spawning seasons, its impossible remove them, you might get a lot of the adult fish, but you wont get the fry.

A swim bladder parasite called Anguillicola crassus was introduced from Japanese eels that were imported to Europe to be farmed. It's thought that adult silver eels infested with the parasite find it hard to regulate their depth as the swim bladder is compromised, and this is thought to impact on their ability to migrate at sea, where they swim deep during the day and shallow by night. If this is the cause, it would result in much fewer eels reaching the spawning grounds in the Sargasso Sea. This is only a theory, we don't know for sure, but it could well explain the crash in numbers.

Mr Bumble

http://news.mongabay.com/2014/0211-hance-european-eels-whales.html

Interesting read and shows how much there is to learn.

Zzippy

Mr Bumble wrote: »

http://news.mongabay.com/2014/0211-hance-european-eels-whales.html

Interesting read and shows how much there is to learn.

Scientists from IFI got similar results with tagged salmon kelts - several of them were eaten by whales too, with temps going up to 30 degrees for 24 hours then back down to ambient water temp.

SeaFields

Myself and the fishing buddy saw an eel the other week while having a chat on a small footbridge. Genuinely had been years since I saw one.