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Salmon in UK southern chalk streams genetically unique

 BEDFORD TIMES


Jan. 21, 2018


Salmon in UK southern chalk streams genetically unique


Salmon from the chalk streams of southern England are genetically unique, researchers have discovered. The fish are classified as Atlantic salmon but research by the University of Exeter and the Game and Wildlife Conservation Trust shows their genes are distinct from others of the species. The researchers studied five chalk streams in Hampshire and Dorset – habitats they said were under “massive pressure” from human activity.


Classifying chalk-stream salmon as a separate sub-species could make it easier to protect them.


 “Our study provides evidence of the genetic distinctiveness of chalk-stream Atlantic salmon in southern England,” said Jamie Stevens, of the University of Exeter.


“They are as different from their non-chalk cousins as the salmon of the Baltic are, and people have suggested the Baltic fish should be classified as a sub-species. “While we found distinct differences between chalk and non-chalk salmon, we found little genetic differentiation within chalk-stream populations.” Chalk streams – which originate in chalk hills and are generally wide and shallow with clear water – are fed by underground aquifers and have steadier flow rates and more stable temperatures than most other rivers and are less acidic.


The fish are classified as Atlantic salmon but research by the University of Exeter and the Game and Wildlife Conservation Trust shows their genes are distinct from others of the species. The researchers studied five chalk streams in Hampshire and Dorset – habitats they said were under “massive pressure” from human activity.


The researchers studied five chalk streams in Hampshire and Dorset habitats they said were under "massive pressure" from human activity.


Classifying chalk-stream salmon as a separate sub-species could make it easier to protect them.


"Our study provides evidence of the genetic distinctiveness of chalk-stream Atlantic salmon in southern England," said Jamie Stevens, of the University of Exeter.


"They are as different from their non-chalk cousins as the salmon of the Baltic are, and people have suggested the Baltic fish should be classified as a subspecies.


"While we found distinct differences between chalk and non-chalk salmon, we found little genetic differentiation within chalk-stream populations."


Chalk streams - which originate in chalk hills and are generally wide and shallow with clear water -are fed by underground aquifers and have steadier flow rates and more stable temperatures than most other rivers and are less acidic.


https://www.bedfordtoday.co.uk/news/national/salmon-in-southern-chalk-streams-genetically-unique-1-8357489