Bass v Salmon& Sea Trout ?

[Julian Fox]

Wurzel

 

We'll be waiting for your follow up report no doubt containing your detailed rebuffing of the science with interest then.......

[dartangler]

Hi All,

Thanks to those that responded - some interesting comments! Been too busy fishing to reply earlier - Conservation Politics can take second place! Last nocturnal sortie to Totnes Weir in difficult conditions - swirling mist and dropping temperatures- did result in success. Landed one sea trout, but lost two with those rubber hooks again! Pleased to see my guest caught his first sea trout ( 4lb 13oz) for a few years. However the really interesting thing, other than the sight of a metre long lamprey on the Weir face and other than having to chase a seal out of the pool before we started to fish, was that all rods on the night that I spoke to had just caught at least one bass - largest reported 1lb 8oz.

Having fished the Dart for 25 years or more this really is an unusually high number of bass and early stage of the season for this to occur!

I did not really expect any answer to the bass v sea trout/salmon debate and my personal dilemma as a game fisherman Chairman, formerly Secretary of the local Dart Angling Association together with being a Member of Devon Sea Fisheries Committee, a recreational sea angler and shortly to be a commercial fisherman, as part owner of a soon to be launched 9.95M Cheetah Cat that will be rod and line fishing for bass for part of the year, continues!

To answer just a few of your comments:-

Colin W - thanks for correcting the date to 1990. Unfortunately this adds to the dilemma as the recorded declines did not really get a mention until the 90's with the rate of decline escalating from around 1995 onwards. We have no real management information systems on the Dart and the only real record is based on the recorded rod and net catches. These were around 5000 for salmon in 1900. Had declined to around 2000 in the early 80s and had fallen to around 500 by 2000, despite increasingly progressive voluntary and mandatory catch restrictions introduced incrementally through the 90's. We finally managed to negotiate a partial 10 net buy-out in 2004 and work with the remaining 3 nets towards future sustainability?

Wurzel- you old rogue - the Dart is fly only for sea trout and how did you manage to get onto our private fishery at Totnes Weir? Please send any fine money to me! The Bacon factory is long closed, but the leat is still open, even if the EA could not tell me what the abstraction licence conditions were, when I asked them a couple of weeks ago as part of ongoing debate into their "Restoring Sustainable Abstraction" programme! Worryingly the Weir face is now almost dry, and it is only May! We know what research into salmon migration states - if they are prevented from entering the river by factors such as man made barriers or low flow - up to 50% may return to sea and are unlikely to return to spawn!

I disagee with you and personally believe that the bass nursery areas here in the South West have done a great deal to restore the bass stocks. The Dart appears full of bass. I fished Salcombe Estuary for giltheads the other day and was plagued by bass to 40cm.

Ryford Andy I take your point about other issues and will be continuing my ongoing fight against over abstraction, habitat degradation and pollution, particularly endocrine disruption from STW discharges - that from Buckfast STW on the Dart containing OP and SP waste from the commercial effluent from a mill scouring sheep fleeces. Submissions I made in to the Minister in 1995 on this subject and about the combined impact of STW components remain unresolved to this date. I also take the point about monofilament netting, whilst recognising the good work that the SFC has already done by using the S&FF Act to limit fixed engine nets along much of the Devon coastline. However please do not lose sight of the fact that increased bass numbers in the estuary may just be another factor in salmonid decline.

Leon I am disappointed by your comment "Maybe we shouldn't be worrying too much about the smolts" . Whilst I note you relate this to the research based projection on bass stocks, the declines in salmonids are already here and also require actions now!

I personally do not know what the impact on salmonids by the introduction of bass nursery areas has been. Nor can I speculate too much on what will happen if bass stocks and or size limits are increased. However I do believe, given the fact that the Dart and other SW Rivers arise in the Dartmoor SAC, where salmon and their routes to the protected SAC area have protected status, that proper consideration should be given to this potential problem. If necessary the precautionary principle should apply until we know for certain!

I have therefore written to Ben Bradshaw on the subject. Perhaps he and his "luminaries" in DEFRA and CEFAS might be able to shed some light on the subject?

I know that this may have an impact on the BASS Management Strategy, currently it does not figure in the document. However it should in my opinion form part of any RIA, if legislation is to be introduced on the back of that document.

Best Regards,

David

 

PS Hot off the press- after a phone call I have just received whilst typing this - from a fellow DAA Member if anyone could tell me the approx weight of a well conditioned 38" sea trout released last night along with others estimated at 10 and 9lb I would be obliged! Did my pal catch the one I lost - Lucky b..... !!!? I shall be returning tonight even more " green" than usual.

[steve pitts]

Hi David

An interesting thread and one to set the cat amongst the pigeons for sure.

 

I'll start by saying that I am a member of BASS, so accept that I may not appear impartial, but I am trying to look at this objectively as it is a very valid point that you make and although I don't fish for salmon or sea trout, I have a high regard for these species - they need all the help they can get!

 

I think that your data from 1900 to 1980's is quite telling

We have no real management information systems on the Dart and the only real record is based on the recorded rod and net catches. These were around 5000 for salmon in 1900. Had declined to around 2000 in the early 80s and had fallen to around 500 by 2000, despite increasingly progressive voluntary and mandatory catch restrictions introduced incrementally through the 90's.

 

The catches had declined by 60% without the bass nursery areas or the current influx of small bass into the Dart.

 

That is a huge drop by any standard (bearing in mind the methods used and two World wars when fishing was less intensive) and unless the catches dropped steeply over a short period, could indicate that a gradual decline occured over this 80 year period.

 

20 years on and in 2000 the catch was only 500 - a further drop of 75%, despite C&R being encouraged and practiced.

 

Of course, most salmon and sea trout runs are nowhere near as prolific as they once were. Catches to rod and line and netting are down on catches in the 50s to 70s in almost every salmon river in England, Wales and Scotland.

 

I would doubt that many bass frequent Scottish estuaries (some are experiencing bass on the West coast Scotland), so if bass are not present in 'threatening' numbers, some other cause has to be considered.

 

Some improvements in salmonid returns have been recorded where netting licences have been bought out and the recoveries have been seen in a reletively short time frame.

This could be a coincidence of course, as salmonid runs can be cyclical - good and bad years.

Maybe the nets have been bought out just before a good succession of runs has occured.

The only benefit then would be that the fish would reach further up the river system (rather than being caught inshore or in the estuaries) and I would guess that a larger number would reach the reds - assuming that there aren't man-made obstructions that they couldn't negotiate and that the reds were in suitable condition (hadn't been extracted for gravel or water abstration reduced the flow etc.)

 

Steve G's assumption that there must be sufficient adults successfully spawing is a valid point.

Just how many smolts it would take to ensure a viable spawning season is not something that I would care to speculate over, but there must, I would have thought, need to be a certain critical mass to offer any chance of a consistant number of returning adults. The odds of each smolt returning must be huge, bearing in mind the numbers that must succum to disease, predators and capture before they return.

 

Which I guess brings us back to predation of salmonids by bass.

I would imagine that bass would eat smolts and small salmonids if they get the chance, so any bass hanging around in the Dart would certainly get the chance to eat sea-bound smolts, below the weir.

There are lots of small bass around, compared to say 10 years ago, so maybe bass pose a bigger threat than they did in the 90's, but I go back to my first point - that salmonids were well and truly knackered, compared to the 1900's or even 1980 before the introduction of bass nursery areas and some of the bigger bass year-classes like 2002.

 

Bass may be taking smolts and thereby in some way hindering the recovery of salmon and sea trout abundance, but where no other possible causes can be attributed to a delay in increased numbers - until we can rule out netting, water and gravel abstraction, made-made obstructions, diseases and other predators (seals, sea birds, otters, pike etc.) I can't see that we can blame bass as the sole culprit.

 

Cheers

Steve

[dartangler]

Hi Steve, Thanks for a well considered response! I have been a very active campaigner for salmon and sea trout conservation for many years and certainly would not solely blame bass predation on smolts for the current state of salmonid stocks! As I well recognise there are many problems affecting salmonid fisheries and this of course preceded the nursery area status on my local River Dart. Incidentally independent research conducted by the Westcountry Rivers Trust on the Dart compared with some other SW Rivers showed that for some as yet unaccountable reason the rate of decline here, based on EA juvenile surveys, was higher than on the other rivers - additional endocrine disruption factor? Until I spoke to Paul Knight at S&TA recently I had not given the bass subject a passing thought. However now the issue has been raised it does pose some difficult questions! Just how much predation by bass within estuaries does actually occur? What impact have the bass nursery areas had since their introduction? What would be the consequences of a size increase? We have always had some good sized bass in the estuary anyway! As nobody really fishes for them within the estuary nowadays we have no real knowledge of just how much the stock has increased - nor do we know how the size differentation has altered. Our anecdotal experience based on the inadvertant ctaches whilst sea trout fishing, together with some limited information from shore anglers, is that there does appear an increase in both numbers and size. If correct, then presumably this may impact on the predation rate on smolts. As our salmonid stocks are endangered then it is important to consider all the various elements that may be compounding the problems. Is bass one of these?

I fully realise this is a difficult subject for BASS for whom I have a great deal of respect, albeit there are areas of the Bass Management Plan with which I do not fully concur. I personally would like to see all species of fish flourishing and with it the sport of angling in all its guises. I would also like the commercial sector to thrive as well! I also firmly believe that all sectors have to work together to solve the many problems we all face.

However this subject will not go away and has to be addressed. It certainly puts me in a dilemma and I have no answers personally! I await a response from the Minister, but am not holding my breath. I am happy to communicate with BASS at any stage. It is many years since I last fished with John Leballeur!

My best regards, David

[Jaffa]

Hi Steve,

 

 

Bass may be taking smolts and thereby in some way hindering the recovery of salmon and sea trout abundance, but where no other possible causes can be attributed to a delay in increased numbers - until we can rule out netting, water and gravel abstraction, made-made obstructions, diseases and other predators (seals, sea birds, otters, pike etc.) I can't see that we can blame bass as the sole culprit.

 

I guess you could add a few others to that list, like food availabilty for the adults on the sea grounds; and therefore plankton and oceanographic conditions, etc etc.

 

Im curious as to why so many environmental and angling groups seem to accept as "fact", the notion that sea lice from salmon farms MUST be the cause of declines in catches on West Scotland (or Canadian) systems, when so many scientists that know about salmon lice are far from certain thats whats going on.

 

 

 

 

Chris

[steve pitts]

Hi Steve,

I guess you could add a few others to that list, like food availabilty for the adults on the sea grounds; and therefore plankton and oceanographic conditions, etc etc.

 

Hi Chris

 

There are no two ways about it - salmonids are under pressure from many quarters.

We haven't even touched on the theories relating to fish-farm escapees polluting the wild-fish genetic pool or the possible negative effects of warmer / drier weather. What about the large numbers of smolts trapped in some power station intake screens? I have even seen a large sea trout eating smolts on the Dorset Frome. This was captured on video by the Institute of Freshwater Ecology (formerly the Freshwater Biological Association) in their fluvarium at East Stoke. They have conducted research into smolt numbers going down river and the subsequent returns. They also tagged smolts with data storage tags and dye markers. I could probably get some stats on % returns if you were interested. You might find some info here -

http://www.fba.org.uk/East%20Stoke%20Page.html

 

These possible influencing factors mostly post-date the 1900 to 1980 reduction that David refers to in the catches on the Dart (and to varying extents elsewhere), so although these combined probably have an effect on the capabilities of salmonids to recover ( if they were given the chance) the long-term errosion of the stock structure over three quarters of a century (either by environmental or man-made influences) may have driven our native salmon and sea trout past the point of recovery.

 

I note in the recent Fishing Focus quarterly publication that grants are being offered by Defra for anyone with a valid marine-based research project. Perhaps Plymouth Uni could be persuaded to look at the plight of the salmon in SW rivers? The money seems to be there and few applicants are queuing for it.

 

By the way - I'm sure that you would find most BASS members very sympathetic to the plight of salmonids in our British rivers. Most are not, as some would believe, single species specialists or obsessives - well, no more obsessive than salmon, sea trout, conger or cod anglers

 

The BMP was never intended to improve bass stocks to the detriment of other species and indeed it was hoped that their would be spin-off for angling by raising the importance of some other species of interest to anglers.

 

Cheers

Steve

Edited May 4, 2007 by steve pitts

[Jaffa]

These possible influencing factors mostly post-date the 1900 to 1980 reduction that David refers to in the catches on the Dart (and to varying extents elsewhere), so although these combined probably have an effect on the capabilities of salmonids to recover ( if they were given the chance) the long-term errosion of the stock structure over three quarters of a century (either by environmental or man-made influences) may have driven our native salmon and sea trout past the point of recovery.

 

Hi Steve,

 

10K years ago this Island was covered in Ice and very little could survive here i guess. From then till now we have an ever changing environment, that maybe suited the salmonids, but its changing and will continue to do so surely?

 

Are you suggesting there is a "right" number of salmon or bass we should have; a "right" environment we should live in?

 

Chris

[steve pitts]

Are you suggesting there is a "right" number of salmon or bass we should have; a "right" environment we should live in?

 

Getting a bit deep on environmental issues for me Chris - I'm just a simple bloke who assumes that salmon and bass co-existed in a balanced marine ecostystem, within living memory and for thousands of years before that.

 

Salmon have everthing against them don't they?

All of the detrimental factors that we have mentioned and many more besides.

 

I think though that environmental factors play a very big role in the survival of smolts and bass fry.

Bass fry are surviving better because of recent milder winters. This is feeding through into lots of small bass, which frequent estuaries until they are big enough to leave for the coastal and inshore zone.

 

Larger than 'normal' populations of small bass may have a negative effect on smolt survival, along with many other factors, but I can't see that the very recent successful bass year-classes are responsible for the demise of salmonids in our rivers during the past 100 years on their own.

 

Cheers

Steve

[wurzel]

Getting a bit deep on environmental issues for me Chris - I'm just a simple bloke who assumes that salmon and bass co-existed in a balanced marine ecostystem,

 

Cheers

Steve

 

How is it possible to get a balanced marine ecosystem?

I suppose you might in a green house but I doubt it happens naturally

[thedogs]

I thought it was the polluted water that did the damage to the salmon, that and overfishing!