Clyde - Gestión del río

River Management

The Clyde is a great example of a 'recovering river'. It is a river where salmon were once extinct due to pollution and man-made structural changes. It now boasts a recovering salmon population but much work is still to be done to ensure the future of the 'Mighty Clyde'.

The Clyde River Foundation seeks to improve fish populations and their habitats and to increase engagement of local communities with their rivers. We aim to achieve this via a combination of long-term monitoring, a sustained investment in education and through community-driven initiatives such as the Clyde Riverfly Monitoring Partnership. By caring for the Clyde we can maximise the health of our rivers for everyone.

The Clyde catchment

The River Clyde, at 170 km, is the third longest river in Scotland. The catchment has a surface area of 3,200 km2 (of which 26.3 km2 is freshwater lochs and reservoirs), and a total river length of 4,244 km. We work across the catchment in eight Council areas (East Dunbartonshire, East Renfrewshire, Glasgow City, Inverclyde, North Lanarkshire, Renfrewshire, South Lanarkshire and West Dunbartonshire) and these are home to 33.8% of Scotland’s human population.

Clyde catchment facts

• Home to 1.79 million people (33.8% of Scotland’s human population)
• 4,224 km of rivers
• 26.3 km2 of freshwater lochs and reservoirs
• 33 species of freshwater fish
• 67% of water bodies at “less than good status” under the European Water Framework Directive
• No District Salmon Fishery Board (DSFB) so no statutory body overseeing fish and fisheries issues
• Where are the Upper and Lower Clyde catchments?
• For fishery management purposes, the Clyde River Foundation partitions the Clyde system into the Upper and Lower sub-catchments.
• The upstream limit of access to migratory fish in the River Clyde is Stonebyres Falls near Lanark. This is therefore an appropriate partition between what we consider to be the Upper and Lower Clyde sub-catchments.

Fishing regulations

The River Clyde, at 170 km, is the third longest river in Scotland. The catchment has a surface area of 3,200 km²  (of which 26.3 km²  is freshwater lochs and reservoirs), and a total river length of 4,244 km.

The Clyde River Foundation work across the catchment in eight Council areas (East Dunbartonshire, East Renfrewshire, Glasgow City, Inverclyde, North Lanarkshire, Renfrewshire, South Lanarkshire and West Dunbartonshire) and these are home to 33.8% of Scotland’s human population.

 

 

 

The Clyde River Foundation team has a combined 27 years experience working across the catchment. Our core work and vision is described in the River Clyde Fishery Management Plan. All of their staff participate in an extensive scientific programme, collecting and reporting environmental data to inform the objectives of the Plan. Each team member is involved in the delivery of their education projects and has enhanced disclosure through the Science Connects STEM Ambassador programme.

Biosecurity

This is a parasite which infects the skin, gills and fins of salmon, trout and some other types of fish in fresh water. It is less than half a millimetre in size, so small that it is barely visible to the naked eye. Despite this, it can cause serious damage in some strains of Atlantic salmon.

Why should I worry?

The effects of the disease are so serious that salmon stocks have now been lost completely from many Norwegian rivers, with the particular races of salmon in the affected rivers being lost forever. Gyrodactylus salaris does not occur in UK rivers but experiments carried out in Norway have shown that our salmon, like those of Norway, are killed by the parasite. It is therefore essential that the parasite is not introduced into UK waters.

Can it be eradicated?

To eliminate Gyrodactylus salaris from affected rivers, all types of fish capable of harbouring the parasite must be removed, so restoration of salmon stocks in affected Norwegian rivers has involved poisoning whole catchments. Such remedial work is destructive, difficult, very expensive and likely to take many years. It may also not be successful.

Where does it come from?

Gyrodactylus salaris occurs naturally in the Baltic rivers of Finland and Russia (possibly also eastern Sweden). The native fish of these rivers, including Baltic salmon, are tolerant of the parasite and normally the infection causes them no harm. However, Atlantic salmon in areas where the parasite does not naturally occur have little or no tolerance of it. Some years ago, Gyrodactylus salaris was accidentally transferred for the first time to some rivers of the west coast of Sweden, to Norway and more recently to some rivers in northern Finland and northern Russia.

Is it a notifiable disease?

Gyrodactylus salaris is a listed notifiable disease and legislation is in place to prevent the transfer of live salmon and trout (the main hosts for the parasite) to British waters. This has now been supplemented by EU legislation that recognises the special status of the UK as being proven free of the parasite.

 

What can I do?

This parasite is very hardy and may be inadvertently introduced by fishermen. It is capable of surviving for several days in damp conditions such as plastic bags, wet angling equipment (e.g. bags, waders, landing nets, lines) and the wet surface of dead fish (e.g. bait fish). The parasite can also survive on other fish species including the eel.

Care needs to be taken at all times to ensure that movement of these other species takes place strictly in accordance with statutory fish health requirements. As the parasite has a direct life cycle and reproduces very rapidly, it is possible that even a single specimen imported by accident to a previously unaffected river would be capable of starting an epidemic in a very short time.

Prior to arrival in the UK, anglers travelling from areas which are not designated as free of Gyrodactylus salaris, and in particular from those areas known to be infected, such as Scandinavia, should take the following precautions to ensure that their equipment is not contaminated.

All fishing equipment should be thoroughly cleaned and then treated to kill any parasites by either:

• Drying at a minimum temperature of 20°C for at least two days, or
• Heating for at least one hour at a temperature above 60°C, or
• Deep freezing for at least one day, or
• Immersion in a solution suitable for killing Gyrodactylus salaris for a minimum of ten minutes. Chemical solutions which have been used successfully include Virkon* (1%), Wescodyne* (1%), sodium chloride (3%), sodium hydroxide (0.2%).

* these chemicals are available from agricultural chemical suppliers. The use of trade names is for illustrative purposes only and does not signify endorsement of any particular product.

REMEMBER IT ONLY TAKES ONE INFECTED FISH TO START AN EPIDEMIC

Catch and release

This page is to give advice on best practice to increase the chances of the fish surviving

Playing the fish

If you are 'playing' a salmon you can significantly help its chances of survival by applying the information below. It is worth bearing in mind that less than 7% of smolts return as spawning adults, therefore, it is vitally important that the angler who is planning to return his catch is able to tackle this with success and confidence.

Ensure your rod is strong enough to subdue a fish quickly 1 minute per pound weight is a reasonable suggestion for time for landing a fish. To avoid exhausting the fish it is prudent to use 15-20lb leader material where possible. Salmon are not renowned for being cautious about leader visibility. When playing the fish it is the anglers aim to move the salmon out of the fast current into quieter water and have the angler positioned slightly below the fish.

By being below the fish you are able to ensure the salmon is battling the current as well as the anglers tackle whereas if the angler is upstream of the fish the angler is fighting the current and the fish. The fight time is therefore lengthened, perhaps un-necessarily. Make sure you pick a safe place to bring the fish to land. Once the fish is subdued bring it quickly to the bank for hand or net capture.

Landing the fish

Research has shown that exposing a salmon to air for even a short period, for example to take a photograph, can significantly reduce its chances of survival. Keep the salmon in the water at all times. Do not at any time lift a salmon up by the tail as this can damage the tendons in the tail of the fish. Later in the season as the salmon nears spawning time, lifting a salmon by the tail can cause the egg sacs in females and milt sacs in males to rupture into the body cavity which can kill the fish in extreme cases thereafter. At all times support its belly whilst handling the fish in the water.

Use a large Gye-type landing net with knotless mesh which reduces damage to the fish's scales. It is wise to avoid beaching the fish as this again can remove protective mucous and scales from the fish which can lead to fungal infection. The salmon that is being returned cannot be gaffed or tailed by mechanical tailer, as both implements cause considerable damage to the fish and were used historically when fish were being killed by the angler, in the days before the catch and release initiatives, that are currently in place through out many river systems in the UK.

Always handle the salmon with wet hands, or put on soft cotton gloves which need to be wet, when removing the hook from the fish's mouth or body if accidentally foul hooked. This prevents removing the fishes mucous which is the fish's first line of defence against disease and parasites.

It is very important that the fish is kept in the water after being captured and the fish should be supported from beneath, with the hook gently removed either by hand or by means of long-nosed forceps or hook releasing tool. If a hook is deeply embedded and cannot be removed, the leader should be cut close to the hook, as fish released with the hook attached will generally survive, and try not to squeeze the fish too hard, and never hold it by the gills at all times.

Reviving and releasing the fish

After removing the hook, or cutting the leader and leaving the hook or fly in the fish, then we should ensure that the salmon will be supported in the water, facing into the current to allow oxygen uptake by the fish's gills, and given sufficient time to the fish for it to recover. Hold the fish gently until it is capable of swimming away strongly, you will know it is time when you feel it starting to pulse and kick softly. If you release the fish and it turns 'belly up' then quickly capture the fish and support it again for a while facing into the current to allow more oxygen to be absorbed. When the fish is being fought there is lactic acid produced in the muscle tissue which creates oxygen debt and the muscles cannot function adequately Indefinitely.

Avoid weighing the fish if at all possible and if you have to then weigh the net with the fish enclosed in it, a Maclean net is suitable for this. A tape measure or a marked off wading stick can also be used to take the approximate length while keeping the fish in the water.

Alternatively, to accurately measure a big fish capture, an angler can run a length of monofilament or fluorocarbon from a spool, measuring from the fork of the tail to the nose of the fish and tie a knot. Continue to run the mono round the girth of the fish and tie another knot. By cutting the mono just above the second knot the angler has a length that he/she can measure against a tape measure later. Ally Gowans has a calculator for predicting the size of fish which is available on the internet here.

I am sure anglers will find this advice most helpful. Perhaps one day beats may supply this information to visiting anglers on small laminated leaflets with beat conditions. Survival rate is greater at water temperatures below 20°C so be aware of the necessity to quickly subdue and return the fish during the summer months.

Survival chances of released Salmon

There has been research carried out by a number of fishery trusts that has shown that the survival rate of salmon caught and released may be close to 100% when we apply the above guidelines and practice.

Spawning success and viability of eggs may be unaffected in salmon caught and released in late autumn using the above guidelines, and they can recover within twenty four to forty eight hours of being captured and are able to spawn successfully.