Illustrated talk by Mike Jenkins, Environment Agency Wales Biodiversity team
About twenty members and friends were fascinated by Mike Jenkins’ talk on Welsh freshwater fish. He started by saying that there is a total of 37 species of freshwater fish in Britain (including non‐natives) but only 23 in Carmarthenshire of which 14 are native. British fish distribution has resulted by their colonisation of rivers and water bodies following the retreat of the ice sheets at the end of the last glaciation when Britain was still joined to mainland Europe and when the Thames formed the lower reaches of the Rhine. This provided a connection which enabled fish to travel from areas of the continent which had remained ice‐free. Arctic char Salvelinus alpinus and Coregonus (including the Vendace and Gwyniad) are species which only thrive in cold waters and were among the first species to colonise following the retreat of the ice. They are now confined to just a few upland lakes, for instance in Snowdonia and the Lake District. The Environment Agency consider them to be at risk of extinction due to the current warming of the climate and are undertaking a project of translocation to establish new populations in lakes at higher altitude, where water will remain colder in years to come. In the Lake District they have used Llamas to take fish to higher altitudes and, in more inaccessible places, helicopters.
Fish live in different habitats which are provided by different rivers or in different sections of the same river. For instance, many of Carmarthenshire’s rivers are spate rivers such as the Amman and Cothi, which provide riffles, pools and runs as well as bed‐rock or shingle‐lined channels. The meandering middle reaches of the Tywi and Teifi offer still or slow‐flowing pools and back‐waters whilst also providing depositional shingle shoals, shallow riffles and fast‐flowing runs. On the coastal levels, rivers such as the Afon Goch at Bynea and Afon Dafen have sluggish flows with marginal reed fringes and can be compared with the similar but much larger rivers which drain the East Anglian Fens.
Mike then described the life cycle of the Atlantic salmon Salmo salar and a microscope image of a scale showing the growth lines, very fine and narrow in the first and second year in freshwater followed by much wider lines indicating the much more rapid growth rate during succeeding sea‐water years and culminating with first, second and third spawning marks. He then went on to describe other salmonids which occur in Carmarthenshire including the Brown trout Salmo trutta and the introduced Rainbow trout Oncorhyncus gairdneri and showed a picture detailing the differences between the salmon and sea‐ trout, the migratory form of Salmo trutta.
Species from other families were then described: Minnow Phoxinus phoxinus. Gudgeon Gobio gobio, Stone loach Noemacheilus barbatulus and 3‐spined stickleback Gasterosteus aculeatus. In common with the Salmon, the Eel Anguilla anguilla is another migratory species which spawns in the Sargasso Sea and goes through various stages including the elver, thousands of which were a frequent sight in the past, wriggling across damp grass between water‐courses. Now the Eel is a relatively uncommon species.
The protected Allis shad Alosa alosa and Twaite shad Alosa fallax, also known colloquially as Alewives and Mayfish, occur in Carmarthenshire’s estuaries and spawn in the lower reaches of the Tywi. The Bullhead or Miller’s thumb Cotus gobio is common in Wales but has declined in other parts of Britain and as a result has been included on the list of UK Biodiversity Action Plan Priority Species.
Mike next mentioned the lampreys: Brook lamprey Lampetra planeri, River lamprey Lampetra fluviatilis and Sea lamprey Petromyzon marinus. River Lamprey and Sea Lamprey are species which are parasitic on other fish and attach themselves with their mouth‐parts that are adapted as suckers. He showed close‐ups of these, of salmon with lampreys attached and the resulting damage after they had been removed. Lamprey was once considered a great delicacy and a surfeit of lamprey pie was the cause of Henry I’s death! An old recipe on how to make a lamprey pie, taken from the book by Hannah Woolley (1622‐1675) printed at the White Lion in Duck‐Lane, near West‐Smithfield, London in 1672, entitled: “The Queen‐like Closet or Rich Cabinet Scored with all manner of Rare Receipts for Preserving, Candying and Cookery” instructs the cook to:
“Take your Lamprey and gut him, and take away the black string in the back, wash him very well, and dry him, and season him with Nutmeg, Pepper and Salt, then lay him into your Pie in pieces with Butter in the bottom, and some Shelots and Bay Leaves and more Butter, so close it and bake it, and fill it up with melted Butter, and keep it cold, and serve it in with some Mustard and Sugar”.
Sturgeon Acipenser sturio, another fish associated with royalty, has occasionally been caught in the Tywi and Mike showed the famous photograph of the specimen “Caught by Mr Allen on the Tywi at Whitemill in 1933 weighing 388lbs”.
Non Native Welsh Fish are Grayling Thymallus thymallus, Pike Esox lucius, Perch Perca fluviatilis, Rudd Scardinius erythropthalmus, Tench Tinca tinca, Carp Cyprinus carpio, Bream Abramis brama, Roach Rutilus rutilus and Crucian carp Carassius carassius and there have been requests to introduce Wels Siluris glanis, a type of catfish. Chub Leuciscus cephalus and Barbel Barbus barbus, although common and widespread in England are not found in West Wales, they are present on the Usk and Wye. Finally, Mike mentioned the latest addition to the Carmarthenshire fish fauna, the Topmouth gudgeon Pseudorasbora parva, which has recently been found in Ashpits Pond, Pwll, probably brought‐in with fish‐stocks introduced by fishermen.
The talk prompted considerable discussion over tea, following which, Mike was thanked profusely for taking the time to prepare and deliver his most entertaining presentation.