Review of a Talk on the Ayrshire Rivers Trust

by Peter Minting


The Ayrshire Rivers trust was started in 2002 with the purpose of monitoring river quality, undertaking fish surveys, providing education on matters relating to river conservation as well as a range of other tasks.


River quality:
The Rivers trust supports the work of the Scottish Environment Protection Agency (SEPA) with regard to the quality of the rivers in Ayrshire. By sampling and monitoring the level of invertebrates living in the river a clear indication can be gained as to river pollution. The stone fly requires very clean fast running water so if found in good numbers it indicate low levels of pollution and a river in good order. 
 
Pollution can occur from many sources.  For example, farm output in the form of slurry (animal waste) or nutrients both cause damage to the water by creating high nitrogen levels which encourage the growth of algae and bacteria and harm the fish population.  Pesticides used without care can pollute long stretches of river. 
 
Sewage outflow after a storm will also damage a river.  Sewage treatment plants are designed to treat a maximum volume of effluent so heavy rainfall that causes the volume of sewage to exceed the design limit will inevitably result in excess untreated sewage bypassing the treatment works and running directly into the river. 
 
Surprisingly, litter on its own, whilst unsightly, does not necessarily cause pollution.  In fact eels are particularly keen on nesting in shopping trolleys!
 
It is relatively rare nowadays for a factory to pollute a river.  A factory wishing to discharge waste into a river or into the sea must seek consent and this should prevent the water from attaining toxic levels.  However, industrial activity can cause environmental impact on rivers in many ways.  For example, coal mining can cause pollution indirectly by reducing the natural water flow from small tributaries resulting in the main river having reduced flow.  Road building, such as the construction of the M77, can also restrict the natural flow water in the surrounding countryside.  Also rain water running off the newly laid asphalt will carry quite toxic chemicals that must be carefully filtered and monitored before being allowed to flow into the local river system.  Wind farms can cause problems during the construction phase with the use of concrete and additional road construction.
 
Results of rivers monitoring in 2005:
More biodiversity has been recorded during the last year which would suggest a slight improvement in river quality.  Some local pollution has been recorded.  The river Ayr has shown good water quality in the upper reaches but this reduces to C-class (not suitable for salmon - not meeting EU standards).  On average the river Ayr is mainly B-class. Coalmine pollution occurred in the River Girvan when a mine overflowed.  The river went red with rust and many fish were killed.  A reed bed filter has been introduced to reduce such pollution in the future.
 
Fish surveys:
Fishing and angling are a major interest regarding water quality. The District Salmon Fishery Boards (DSFBs) and SEPA look at all species of fish and perform regular surveys to monitor fish numbers.  One method used is called electro fishing in which an electric current is passed into the water which attracts the fish toward you allowing them to be netted.  This is particularly useful for counting juvenile salmon (salmonids).  When fish are netted, the rings on their scales are like tree rings in that they show the growth in each season.  At about two to three years old the salmon becomes a smolt and heads for the sea.  One matter for concern is that the salmon are returning from the sea earlier than normal resulting in smaller, weaker adult fish.  This may indicate a problem with seawater.
 
Unfortunately, it is difficult to equate the records of salmon in the rivers today with past records.  Early records included netting salmon, a practice that is only undertaken nowadays on the Solway Firth.  As a result, there is really no long-term data on which to base salmon numbers.  Rod caught data also has difficulties as there are often catch limits per rod which distorts the results and local Angling societies import fish to increase fish stocks. Peter then gave us a detailed description of the distribution of fish in our Ayrshire rivers.
 
Ayrshire Fish:
Naturally occurring species:
Atlantic salmon-
Wild Atlantic salmon migrate to the waters around Iceland and Greenland whereas trout stay within a few miles of the River entrance.  Escaped farmed salmon are distinguishable by their fat body and damage to fins due to lack of exercise and very close proximity to other fish. 
Trout-
Brown trout can turn into sea trout, but not all do.  Females are twice as likely to become sea trout, perhaps due to there being better food sources in the sea that are needed by the females to create their eggs. Sea trout returning to our local rivers has now become quite rare.
 
Arctic Char-
Arctic Char are exclusive to Loch Doon, which is why Loch Doon is now a site of special scientific interest (SSSI).  A major problem experienced with Loch Doon is that it is based on granite which has no PH buffering capacity for acid rain.  As a result the PH of this loch is currently 4.5 or less and salmon need 5.5 or more to successfully breed and trout 4.5 or more.  The breeding requirements of the Arctic char are unknown but the population levels are steadily dropping.  The acidity of the water is likely to be a major factor and efforts are being made to try and correct the problem.  One method being used is to line the forest paths with crushed scallop shells which dissolve in the rain feeding alkaline water into the rivers flowing into the loch.  Of course, this would require tens of thousands of tonnes of scallop shells to achieve the desired effect.  In addition alongside the paths are habitats of exotic orchids that require acid soil!
 
Lampreys-
Lampreys are migratory, so are easily blocked by river dams, etc., and these fish are recognised as a threatened species.
 
Introduced species:
(introduced on purpose or by accident)
Grayling were introduced by accident and are are quite well distributed on the river Ayr. 
 
Rainbow trout were introduced by accident.
 
Pike and Perch introduced on purpose and occur in slow and still waters such as lochs.
 
Stoneloach, Gudgeon and Minnows were introduced on purpose for live baiting.
 
Estuary species:
Grey Mullet, Flounders (flowing up to 3 km inland) and Sparling.
 
Other work of the Trust:
Future studies and research discussed by Peter include the analysis of fish genetics in which DNA taken from locally caught fish is compared with data on a World database.  The fish tagging is a very expensive form of research but can reveal important information on the movements of fish in our rivers and the Trust is hoping to use this technique to survey Ayrshire rivers.  Fish are netted and fitted with an electronic tag that can be monitored by devices in the riverbank giving detailed information on the day-to-day movements of individual fish and helping to identify specific problems with the river.
 
The activities of the Ayrshire Rivers Trust include a range of projects on river restoration. The monitoring of fish movements over obstacles such as weirs allows the Trust to identify obstructions that are preventing easy access by fish to other sections of the river. Designing and undertaking bankside reconstruction where problems have been identified such as insufficient banksides (leaving fish unprotected), landslips where the bankside has collapsed into the river and over shading (where, for example, the river edge is too close to a conifer planting) cutting out light and life from that section of river.  Fish do not like sections of river that are artificially straight and lack places to hide and rest from the river current such as behind boulders and irregularities in the bank.
An important part of the trust's work is in the area of education and involves presentations at schools, clubs and societies (such as our own).  A very successful activity has been "salmon in the classroom" in which Ayrshire schools have taken responsibility for hatching about 100 salmon eggs (supplied by local hatcheries) and released them into their local river.
 
Membership of the Ayrshire Rivers Trust:
Peter pointed out that they are always grateful for new members of the trust: with the cost of 10 for adult membership and 5 for Junior members.  Members receive regular information about news and events and can get involved in the voluntary activities associated with the Ayrshire Rivers Trust. Their website can be found at www.ayrshireriverstrust.org or you can contact them by phone on 01292 525142.
 
Many thanks to Peter for introducing us to the important work being undertaken by the Ayrshire Rivers Trust. We wish them every success for their future activities.
 

 

 

 

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