Red algae growing in Cornwall’s Fal Estuary is genetically unique, new research shows.
Scientists said the findings support the need to protect the maerl bed which is “very much at risk” from factors including marine pollution.
The researchers, from the University of Exeter, looked at a maerl-forming red algal species: Phymatolithon calcareum, which spans the north-east Atlantic, from Norway to Portugal.
They found that algae from the Fal Estuary is “genetically distinct” from other algae sampled, including from the Manacles, which is a site just eight miles away.
Maerl beds play a similar role to tropical coral reefs with the researchers saying they are “vital habitats for a diverse array of marine species”.
The paper, published in the journal Evolutionary Applications, said the Fal Estuary site “harbours unique genetic diversity” which had likely developed over a long period of time.
Dr Tom Jenkins, of the University of Exeter, said: “It appears that the unique diversity in the Fal Estuary has likely been shaped over time by geographical isolation of this maerl bed and a lack of genetic exchange with other P. calcareum populations.”
The paper said the findings “provide further evidence to support the current conservation management objectives of this SAC [Special Area of Conservation] to maintain the maerl bed in a favourable condition”.
Dr Jamie Stevens, of the University of Exeter described the Fal Estuary as a busy waterway heavily used by commercial and naval shipping accessing Falmouth port.
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He said: “Consequently, the genetically unique Fal maerl bed is very much at risk from marine pollution and the threat of sedimentation from dredging which is undertaken periodically to maintain navigable access to the port.
“There are several large maerl beds around the coast of south and south-west England, and the genetic differences we identified show that these need to be managed on a site-by-site basis, as separate and distinct populations.”