A local fisherman with a recent 30lb salmon caught in the River Wye.

Salmon stocks rapidly diminished due to a number of factors including pollution, habitat degradation and overgrazing of livestock.

The top of the river is at fairly high altitude and full of forestry and as acid rain fell, it made its way into the river, wiping out growing areas and salmon habitat in the tributaries.

Over the years a number of pollution incidents have occurred including the accidental discharge of 20 tons of sugar at Hereford in1994.

The following year the River Elan (an Upper Wye tributary) and the Upper Wye itself both received an inadvertent chemical release which killed tens of thousands of juvenile fish.

A healthy river would normally have a pH balance of around 6.5; the Wye during its worst period fell as low as 4, at which point fish reproduction can be affected. Vinegar has a pH balance of between 2.4 - 3.4.

Flood defence schemes on the Lugg - a major Wye tributary were also a contributing factor as fish passes were not initially included, preventing fish from migrating.

Habitat degradation caused by overgrazing of sheep was another contributing factor as the increased livestock (caused the river to become wider and shallow rather than narrow and deep which is preferable to the salmon and brown trout.

A 15lb salmon being returned at Upper Bigsweir on 3 March - The Wye and Usk Foundation

The historic practice of coppicing also ceased many decades ago which meant trees such as alder began shading large areas of the river banks, killing off the ranunculus weed which provided habitat for insects and their larvae - a vital food source for the fish.

In 1997 work began to improve the river and the results are now being seen. Despite the lack of rainfall, the River Wye is enjoying the best start to the salmon season for at least 20 years and after less than four weeks fishing, 95 fish have been caught and safely returned.

A decade ago the total salmon catch for March and April was just three.

Four fish have been over 30lbs and 27 more than 20lbs, evidence that the monster 'portmanteau' salmon, for which the Wye was famous last century, are returning.

Other positive evidence is that a much higher than average number of 'kelts' (salmon which have spawned) returning to the sea, have been caught, indicating good levels of spawning fish from last year.

Dr Stephen Marsh-Smith, Director of The Wye and Usk Foundation, explained: "The success has been very much the result of partnership working."

Adding a note of caution, Dr. Marsh-Smith says: "In spite of this excellent start, we are now seriously short of rain and salmon catches are increasingly confined to beats below Monmouth that benefit with fish coming in on the tides."

Watch salmon on BBC Wildlife Finder.

BBC Wales News: 'Timeless Wye' is voted public's favourite river.

BBC Wales News: Climate change danger to salmon in River Wye.

Previously, it had only been found as far north as Southern Biscay in the Atlantic, with the odd one seen more northerly off the coast of France, but never before in Welsh waters.

Dr Mandy McMath, Senior Marine Ecologist for the Countryside Council for Wales (CCW) said, "Some species, if recorded routinely, could reveal important information on climate change and seasonal migrations. The sighting of more southerly species in Welsh waters indicates a possible rise in sea temperatures."

Paul Kay, co-author of 'Marine Fishes of Wales' would love any fishermen, rockpoolers, divers and people interested in identifying fish to report any unusual sightings to www.fishrecording.info

"There are gaps in our information about endangered species so all information will help us build up a better picture of fish species in Welsh waters."

Related links:

www.ccw.gov.uk

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Pipe fish. Photo: Paul Kay

It is thought to be shore or black-striped pipefish (Syngnathus abaster) which has previously only been seen as far north as the Southern Biscay in the Atlantic.

Dr Mandy McMath, Senior Marine Ecologist for the Countryside Council for Wales (CCW) said: "Some species, if recorded routinely, could reveal important information on climate change and seasonal migrations. The sighting of more southerly species in Welsh waters indicates a possible rise in sea temperatures."

Paul Kay, co-author of the Marine Fishes of Wales said: "It would be great if rock poolers, divers, anglers, fishermen or just anyone interested in identifying fish would go to fishrecording.info to report any unusual sightings. There are gaps in our information about endangered species so all information will help us build up a better picture of fish species in Welsh waters."

Mandy McMath, CCW marine specialist said: "Some species, if recorded routinely, could reveal important information on climate change and seasonal migrations.

"We are also keen to hear from people who see unusual and endangered species, species where information gaps exist such as information on migratory species at sea; and species encountered by commercial fishermen and anglers."

Paul Kay of Marine Wildlife is also interested in hearing from people who know of local place names that refer to fish or Welsh colloquial names for fish species.

"For example, Porth Ysgaden in Pen Llyn, Gwynedd, translates as Herring Port. Although no herring are found here now, they must have been an important resource in the area in the past."

If you've any information to share, get in touch with Paul via the marine wildlife website.

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Countryside Council for Wales

Marine Conservation Society

Welsh Federation of Fishermen's Associations

"The sea-dwelling parasite attacks fish, burrows into it, and then devours its tongue. After eating the tongue, the parasite proceeds to live inside the fish's mouth".

Visit treehugger.com for more on this story.

Fishermen found the parasite living inside the mouth of a weaver fish in Jersey. Weavers are common throughout the UK and can be found close to the shore in Wales during the summer months.

If you've ever stepped on one, then you'll know how much pain they can cause!

More on this story from BBC News

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Unknown to me it had just made the journey all the way from the Sargasso Sea (south of Bermuda) and now it was in my hand, measuring only eight centimetres or so.

Eels are one of the truly great animal mysteries. No-one has ever witnessed or found them spawning. It's puzzled people for many years: Aristotle thought they came from rotting seaweed and even Sigmund Freud kept one to try to find out the answer.

It has been deduced that they spawn in the Sargasso Sea and make their way across the Atlantic as tiny creatures using the oceans currents such as the gulf stream.

They then travel up rivers, climbing weirs and other obstacles to make it to into the river system, an incredible effort for such a small fish.

They will spend most of their lives in fresh water and grow in size until it comes to the time when as an adult eels (now a pretty hefty creature) start heading downstream (and across land even) and head out into the ocean to start the journey back to the Sargasso Sea.

This will be one final journey to spawn and start the cycle again.

All epic stuff, and in an age of technological advances where people communicate each others' locations using a raft of devices, it's amazing to think that we still don't really know where the eel goes on its journey.

So why am I talking about them now? Well autumn is the time when the adults start their journey and start moving out from the rivers out to sea. It's dependent on rainfall and the stages of the lunar cycle but across the country they are starting their long and final swim.

On a more sober note over the last 20 years there has been a 90% reduction in the population abundance in Europe and this is serious news for our slivery tourists.

There are a number of factors involved: netting, fishing and barriers to migration, not to mention possible disruption from climate change to the currents that bring them across the Atlantic as young.

It is also sad to think not everyone likes eels. Another recollection I have was the attitude from a minority of anglers who took a dim view of eels and persecuted them for tangling their lines up. It's a practice I hope has stopped.

Like many things in wildlife they are inspirational and I'd like them to not go the same way as salmon and disappear from some of our rivers. Best of luck Eels - have a good trip.

And here's a sneak piece of information for you: we hopefully should be meeting some conger eels in this year's Autumnwatch, these huge sea creatures can reach up to three metres long - watch this space!

Wales was particularly affected with the River Wye bursting its banks and the Monnow rising hugely (see the picture) not to mention the flooding in the valleys.

As I mentioned a few weeks back, rivers are extraordinary things when they're in flood and usually wildlife and animals have ways to deal with it.

However it's not always ok. I remember stories from last year's floods of people finding fish in flooded car parks, not to mention the pollution caused by toxins and other harmful materials that large amounts of rainfall brings.

But interestingly the large amounts of water have both good and bad implications. I spoke to Anna Gutherie from the Wildlife Trust about what the possible effects may be.

She said that invertebrates could be at risk with many insects and spiders having been washed away by the flash floodwaters. This would potentially mean that area would bea poorer feeding ground for birds afterwards.

On the other hand, the waters would have meant that many plant species will have been dispersed as seeds or twigs in the flood waters and may have colonised new areas. So it seems it may go both ways as long as the natural balance can be restored.

However, Julian Branscombe from the Gwent Wildlife Trust made an interesting point on how the measures needed to combat flooding could potentially have harmful affects on wildlife and habitats.

He said that the rebuilding and engineering work now needed to lessen the chances of future landslips could threaten native habitats and species. Natural features like spring-lines, old meadows and healthy slopes may be destroyed.

As Julian explained, it all serves to highlight the surprising and insidious ways that the environment can be affected by changes to our climate. At first it may seem that wildlife is simply affected by flooding, then by the measures needed to combat it. But in fact the root cause to all of this may be human-influenced climate change.

Food for thought indeed...

Here's my pick from this week's wildlife web

• One for the spider lovers out there!
• An interesting site that allows you to view Flickrpictures in time and place
• Pictures of the recent flooding

Looking at the rivers it's amazing to think that all the life in them doesn't get washed away in the brown soup marching downstream, but the fish and other creatures are able to somehow find eddies and spots to shelter as it passes.

In fact one species which welcomes the high water is the migrating salmon.

The high water is a green light for them to swim up river from the sea and lower reaches as it gives them enough water to pass waterfalls and other obstacles in their way.

On the Wye, which is one of the longest rivers in the UK, they have reached as far as Builth Wells and make this journey in impressive time if the conditions are right.

Although fish aren't exactly the most charismatic of creatures I still think they are pretty amazing considering the epic nature of their return journey to the place of their birth.

Coal rivers

I went down Big Pit this weekend and it reminded me how the wildlife in the coal mining valleys has bounced back since the time of the coal industry.

In the valley where I live (where Pochin Colliery was situated), we have otters, ravens, peregrines, trout, dippers and kingfishers; the list goes on, and this is only really a few decades after the colliery closed.

In fact, I was talking to a local this week about how he used to fish in the river. He would "time it" for the periods when the river wasn't black because of colliery lorries driving through it!

When this happened he would simply reel in, have a cup of tea and wait till it cleared before starting to fish again.

I hope the weather gets better; fingers crossed but it has made for a few rainbows as you can see from this week's picture.