- Marine macroalgae are rarely considered from the point of view of conservation and the assessment of their conservation status is often limited by a lack of appropriate data. The red algae Grateloupia lanceola is a common inhabitant of Atlantic rocky shores along West Africa that also occurs in a small number of enclaves in the north-west Iberian Peninsula (NWIP).
- NWIP populations are notoriously separated from the main range of the species, and were proposed as candidates for inclusion in the regional list of species of conservation concern.
- In an attempt to provide further information to assess the status of these populations, amplified fragment length polymorphism (AFLP) and mitochondrial cytochrome oxidase subunit 2 and subunit 3 gene (cox2-3) sequences were used to investigate their genetic structure in the Iberian Peninsula. In contrast with the absence of variation in the cox2-3 region, AFLP revealed significant genetic differentiation and a clear isolation by distance pattern for samples separated by 100 s to 1000 km along Iberian shores.
- Together with assignment/exclusion tests, these results suggest that G. lanceola has geographically restricted dispersal, and indicate that NWIP sites are probably demographically isolated from other conspecifics. Therefore, it would be a mistake, from a conservation perspective, to assume that these populations may be subsidized by arrivals from distant populations located within the main range of the species.
- On a regional scale, most NWIP sites cluster into a single genetic unit with low genetic variation. Altogether, these results support the listing of NWIP populations of G. lanceola as vulnerable.
Copyright © 2011 John Wiley & Sons, Ltd.