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- Genetic diversity of a marine foundation species,Laminaria hyperborea(Gunnerus) Foslie, along the coast of IrelandPublication . Schoenrock, Kathryn M.; O'Connor, Aisha M.; Mauger, Stephane; Valero, Myriam; MACHADO, JOÃO NEIVA; Serrao, Ester; Krueger-Hadfield, Stacy A.Worldwide, kelp populations are stressed by warming, increased storms and other anthropogenic disturbances. Marine population distributions are projected to retreat poleward with climate change if they cannot adapt to changing conditions, which would potentially lead to a regime shift in subtidal habitats. In Northern Europe,Laminaria hyperboreais a subtidal ecosystem engineer whose distribution has shifted over millennia, leaving predicted areas of high genetic diversity from the last glacial maximum (LGM) near its southern distribution limit in the Iberian Peninsula. In Ireland,L. hyperboreastructures communities by supporting diverse faunal assemblages and producing large quantities of organic carbon throughout the year. We investigated the genetic diversity of eight populations, ranging from the southern coast to the north-west of Ireland, using nine microsatellite loci. Diversity was found to be highest in Lough Hyne, a Special Area of Conservation (SAC), near the predicted climate refugium. We found evidence of isolation by distance, with high connectivity between populations that were geographically close, probably driven by short range dispersal ofL. hyperboreapropagules. Genetic diversity (measured as expected heterozygosity and allelic richness) was highest at Lough Hyne, and decreased northwards, as predicted from past range shifts. Expected heterozygosity was highest at Lough Hyne (0.706) and decreased northward, with the lowest value at Bridges of Ross (0.283). Based on these patterns, further fine-scale investigation into population diversity, dispersal and potential resilience in Irish kelp forests are necessary as warming and non-native species are observed more and more frequently.
- Rediscovery of Althenia (Potamogetonaceae) in Portugal, 168 years after the last collectionPublication . Frade, Duarte; NEIVA MACHADO, JOÃO PEDRO; Anne Davison; Pearson, Gareth Anthony; Serrao, Ester A.Althenia (Potamogetonaceae) is a small genus of aquatic angiosperms from saline environments that includes the most recently evolved seagrass, Althenia marina. One or two species occur in Europe, both rare and considered Data Deficient at the regional level. We report the first records of Althenia in Portugal since 1853: two populations in the Algarve and a third in central Portugal. As in previous studies, all Portuguese populations include plants with and without visible nerves in the leaf sheaths, a character used to distinguish between A. orientalis and A. filiformis. We tentatively recognize a single Althenia species in Eurasia, pending further studies. We recommend further searches of suitable habitat, as Althenia species are small and easily overlooked, as well as monitoring and safeguarding of known populations through in situ and ex situ conservation.