Fermoy weir

(Smolt)

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Hi Jack,
What's the purpose of the weir? Was it originally used for industry? Why is it being replaced?
 

Marcus c

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I think in a way the two main weirs on the blackwater are still used for industry_ie industrial use as a way of generating money_ 1. Without fermoy weir, the rowing club, that attracts a lot of tourists, wouldn't survive, as the water would be too low for rowing.2 The 2 weirs keep the majority of fish downriver until the really constant high water comes around September _most of the world famous beats are downriver. It is a bit of a grey area, as a lot of income for the area is generated and the fish do get to the beds eventually. Weirs are obstacles to fish at the end of the day.Just my own thoughts and l'm open to correction
 

JACK POWER

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I think in a way the two main weirs on the blackwater are still used for industry_ie industrial use as a way of generating money_ 1. Without fermoy weir, the rowing club, that attracts a lot of tourists, wouldn't survive, as the water would be too low for rowing.2 The 2 weirs keep the majority of fish downriver until the really constant high water comes around September _most of the world famous beats are downriver. It is a bit of a grey area, as a lot of income for the area is generated and the fish do get to the beds eventually. Weirs are obstacles to fish at the end of the day.Just my own thoughts and l'm open to correction

Sorry Smolt, just saw your post now. That's about it, or at least that was about it. Weir first built a million years ago to drive a mill in Fermoy town but whole character of the town is defined by the water held above it where the rowing club operates. Marcus is right but things have changed so much - as in declined - on the Blackwater that some anglers have started lobbying for mandatory catch and release and a curtailed season - at both ends. Commercial angling interests will probably oppose this and we'll have to wait and see how things pan out. For what it's worth I don't think commercially promoted angling is sustainable on the river now. To say that about a once magnificent river is indeed heart breaking - and very challenging for those commercial interests. This year, one famous fishery had only 19 fish to the end of March. In a book on a shelf behind me there are details of an opening day there in the early 1960s when more than 50 springers were caught - and killed - in just one day. All so depressing.
 

seeking

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Indeed very depressing. Those lobbying or the CCR will doubtless be disappointed given CCR is neither required nor does it help restore anything in rivers like this where your massive human and cattle (etc. which has all burgeoned under CAP but in reality EU membership - I note you may not have THIS POST on the Brexit thread...) population increases over recent decades have stuffed-up the rivers further. They were stuffed-up when the weirs went in because such changes to the natural hydrology just reduce the carrying capacity of the river for salmon.

We know salmon can be sustainably cropped as sustainable tasty treats at >50% of the run, so long as the river remains in good nick. 50 springers in a day! Crikey think how great that would be again, but sadly impossible given the non-joined up thinking of soundbiters nowadays.

The good old days were good because they predated the worst impacts of anthropogenic degradation of the rivers that many of your generation propagated, supported and encouraged (incidentally often whilst thinking the EU was a good thing, CAP was wonderful, it was all at sea, or chappers,and CCR would save them and your water quality was never so good!)

More than depressing, it's lunicidal…

:D:):D:):D:):D:)



PS - Dams - destroy them all, otherwise accept reduced runs of salmon over the years, especially as pollution inevitably increases.
 

(Smolt)

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Thanks for the reply's Marcus and Jack. Makes you wonder as the weir has been there since day dot by the sound of it.
Just reading seeking's reply, the argument stating it is all at sea is just as valid as saying its all inland? It is easy to see changes and impacts in our landscape which are as plane as the nose on your face. Here's a thought, there are rivers in Ireland in rural areas with very minimal if any changes to its course and again minimal if any agricultural impact (one has its headwaters in a national park), but these rivers are also declining in returning numbers of salmonids. Why is that? Inland issues need to be addressed but it is now proven (scientifically, where is a graph when I need one) that smolt mortality at sea is increasing and todays salmon do not feed as efficiently as its predecessors have done (comparing scale samples show this).
We have a river in our area which is being used in a sea trout tagging scheme called COMPASS. The ratio of salmon and sea trout smolts in the river is nearly 50/50 approx, but the returning fish are no where near this ratio. This river is rated as a good if not prime sea trout fishery but again, salmon numbers are poor and only going one way.
 

seeking

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Thanks for the reply's Marcus and Jack. Makes you wonder as the weir has been there since day dot by the sound of it.
Just reading seeking's reply, the argument stating it is all at sea is just as valid as saying its all inland? It is easy to see changes and impacts in our landscape which are as plane as the nose on your face. Here's a thought, there are rivers in Ireland in rural areas with very minimal if any changes to its course and again minimal if any agricultural impact (one has its headwaters in a national park), but these rivers are also declining in returning numbers of salmonids. Why is that? Inland issues need to be addressed but it is now proven (scientifically, where is a graph when I need one) that smolt mortality at sea is increasing and todays salmon do not feed as efficiently as its predecessors have done (comparing scale samples show this).
We have a river in our area which is being used in a sea trout tagging scheme called COMPASS. The ratio of salmon and sea trout smolts in the river is nearly 50/50 approx, but the returning fish are no where near this ratio. This river is rated as a good if not prime sea trout fishery but again, salmon numbers are poor and only going one way.

Good points :)

Sorry to pick upon these points but firstly it's not as valid to say at-sea mortality is significant compared to in-river. It's a fact that >>90% of all salmon egg-to-adult mortality occurs in the egg-to-smolt stage and <<10% post-smolt to adult spawner. Changes to the river situation therefore can have a more significant impact than anything changing at sea.

Secondly, the measuring of these relative impacts is easier to do on adults (because of errors estimating from small sub-sections of a large population) than in-river.


I am aware that the SCS such as Salmon Extinction Watch Ireland etc. are keen to ensure "all at sea" and anti-netting stays to the fore for various reasons (some good, some seemingly nefarious) and so they will tout that it is "proven" that marine mortality has collapsed, but clever folk such as yourself can surely agree that this is a hypothesis based on guesstimates and could be very, very wrong.

The data is mainly actually bunk. The mythical "1980s Bush 30% Survival Rate" widely touted appears to be tosh because the guesstimate is just that and a poorly constrained and unscientific series of surveys to the nets (which never took into account straying, errors, mis-assignment etc).

Anyway, we've been over this before many times in the last decade, so I won't go over the old ground but a number of threads by MCX Fisher etc. will add more information, and I will finish with a logical, empirical example to show how guesstimates of massive declining post smolt-to-spawner survival at sea are flawed*:


For 60+ years, Girnock Burn on the Dee has had a adult and smolt trap where they can log all fish in and out.

Max annual adult fish was ~120 early doors, min was averaging 20 quite recently. Quite a range, we all agree and the kind of thing that incurs All-at-sea-itis rage in the SCS.

But over the whole time period, the annual average of outmigrating smolts has stayed constant around 2,500. So carrying capacity for the burn is seemingly fixed and no amount of adding surplus spawners will help (indeed canny minds will note that sustainable cropping >>50% is possible!)

Not only that but we can also demonstrate why the "Bush 30%" guesstimate is, to use a favourite Irish phrase: "total bollix"

Because, if 30% of the Girnock fish returned, there'd have been ~ 750 adults clogging the trap (which has never happened)!!!

a range between 1-5% seems like a maximum for areas where there is proper empirical evidence, rather than black box models etc.) So roughly where we are. But the rivers degrade still further!!!

The issue for the Girnock fish, is they then have to enter the main river and out to sea through various barriers through the harbour etc. Recent studies (delayed because of the SCSs pre-occupation and a priori bias to "All At Sea") confirm that mortality of tagged smolts in the river is huge (probably the singly largest problem being the anthropogenically degraded river [i.e. harbour]) and at the recorded rate, all tagged smolts would be dead if the river were 40km longer!

Of course, the issues don't end there and the fish migrating to the sea are most vulnerable early doors close to shores (e.g. by the salmon farms your country seems to love more than clean rivers) and they will croak then too. Adults by contrast will be at far less risk, drop in the ocean and all that.

The above all explains why some catchments (N Esk vs S Esk, Findhorn vs Spey) do better (first quoted have far less anthropogenic impacts) and why more remote areas N Scotland do better than the Midland Valley etc. Even then of course there's the probability thingd will get worse over time as synchem use and airborne pollutant concentrations increases (difficult to see, measure and monitor), but overall, too many people in these emerald isles...

Regards :)

PS I spared you the graphs but they're on SFF and I can link if you want.


* based on memory - the actual data is quoted by me on other SFF threads
 

(Smolt)

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I think you are right in that we can't just say its all at sea and throw our hands up in the air, as anglers we should be focusing on the issues we can address which are in the vessels of our rivers systems. But the tagging on our local river is a clear indicator that salmon smolt just don't return to the degree that sea trout smolt do, whether this is actually the case and always has been is unknown. But salmon smolt are up against it, whether it is in freshwater, brackish or saltwater.
If it wasn't for the water framework directive I think our waterways would be in a far worse state. Consecutive Irish governments sway to the farming lobby and if the EU wasn't waving a stick there would be little incentive to clean up.

P.S just as an adage there are no salmon farms in the bay which collects the water from our rivers and indeed I think the nearest farm is off the Antrim coast and none to the south of us. Possibly a reason why our sea trout fishing is still (relatively) decent but difficult to add that reason to salmon smolt mortality, unless our smolts travel south first and circumnavigate the south and west coast then intercepting farms.
No river on the east coast of the country is open to harvest and it is interesting to note that the east coast of Ireland has some big towns an cities and high populations. Food for thought.
 
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GeeBee

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The fermoy weir I understand keeping, the town wants to keep it, but the IFI were ordered to remove the clondulane weir in 2013 but have done nothing about it.

I emailed the IFI in Macroom but never got any replies.

Thats the one that should come down, it stacks up the salmon in low water and makesthem easy to catch.
 

meyre

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About that weir , which should have been slighted in 2012, you'd best have a word with Stoker Cavendish who owns it. It seems he was concerned that its removal would damage the fishing alongside the castle.
 

Marcus c

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When you own a fishery and a large number of your regular customers reside in the house of Lords_let's just say local government bodies may feel a bit "shy" about "asking" for their weir to be removed
 

Slaneybs

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When you own a fishery and a large number of your regular customers reside in the house of Lords_let's just say local government bodies may feel a bit "shy" about "asking" for their weir to be removed


We left the jurisdiction of the House of Lords almost a hundred years ago so unlikely to overly influence IFI or Cork / Waterford county councils!
The reverse was probably true why did the powers that be focus on removing this weir and not the one in Fermoy which was just as bad?
There are some worthwhile arguments for keeping the weir. The environmental impact of releasing 150 years’ worth of ***** and pollution from Fermoy trapped in the dead water above, the loss of an area of sanctuary above the weir and the risk of flooding and land loss - there is a fair chance that the altered flow would eat a large hole in fields below given the orientation of the weir.
Those who fish it swear that the fish just skim up the weir even in lowish water given its sloped face. In an ideal world there would be no weirs on the river – there should be a solution to fish passage that doesn’t simply destroy one of the most attractive fisheries in the country just because it belongs to a very wealthy aristocrat.

I have only fished there once for a day ( a blank freezing day several years ago) so I have no axe to grind on behalf of the Duke – it is lovely piece of water.
 

Marcus c

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Everybody has done their best to help with salmon conservation _some anglers have had their waters closed indefinitely, the netsmen that worked in the estuaries forfeited their livelihoods, all anglers are now under scrutiny with tags +logbooks, one of the main fisheries in cork is under brown tag legislation in January _l could rant on_The one thing that defies logic is that artificial barriers to salmon migration remain mysteriously untouched _can somebody explain why?? And yes _ l agree _the stretch below a weir is a lovely piece of water
 
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It’s a strange situation where IFI are seeking to remove weirs in some rivers and actively installing new ones when constructing fish counters in others.
 

nore fly

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The weir in Thomas town on the river nore collapsed a few years ago ...it was a big barrier and was a temperature barrier ...worth having a look at it if you are in doubt about weir removals ...the river has returned to its natural state ...and it has increased the amount of spawning gravels by approximately 2km which were silted up over the years above the weir ..its worth looking at to see how a river can return to it's natural state in a very short time ...
 
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KerrySalmon

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Yes an excellent example of weir removal. River returns to natural state very quickly with minimal damage downstream. Increases productivity for salmonids while reducing predation pressure. It is interesting to see smolt migration being impacted in low water causing delay at these obstacles. Unfortunately weirs are being used to support other leisure industries while rivers suffer and salmon decline. The most recent water quality issues are really hitting home primarily caused by farming and development which does not have adequate infrastructure to deal with waste water. If all the treatment systems were upgraded then salmonids would benefit substantially. As regards farming it is now a runaway industry with little awareness of water quality and little prospect of government intervention except through well meaning but substantially ineffective environmental schemes.
 
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