Erasmo's presentation epitomised the value of creativity in presenting good science. Giant kelp is an iconic species of temperate coasts which are of huge importance to coastal ecology and responsible management. Through mitochondrial and microsatellite markers Erasmo has demonstrated that despite differences in holdfast morphology and blade corrugation, the four forms identified as separate species are really one species with a continuous and oceanographically plausible variation in haplotype frequency due to raft dispersal. His polished presentation on morphological characters, haplotype network, and biogeographic distribution convincingly demonstrated why marine scientists should reevaluate how we view Macrocystis pyrifera.
Benthic Science Student Prize for Thinking outside the square: Creativity in Science in recognition of a presentation which exemplifies good science inspired, conducted, or presented with exceptional creativity.
"Moving around the oceans: Global phylogeography and taxonomy of the giant kelp Macrocystis."
1, School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington, New Zealand
2, Faculdade de Ciencias do Mar e Ambiente, Universidade do Algarve , Campus de Gambelas, Faro, Portugal and
3Departamento de Ecología, Pontificia Universidad Católica de Chile, Santiago, Chile.
E-mail: erasmo.macaya@vuw.ac.nz
Buoyant macroalgae may persist at the sea surface for weeks or months after detachment, which may represent an important mechanism of long distance dispersal. Several studies report high abundance of floating algae in temperate oceans; however investigations addressing the genetic connectivity between algal populations along this area are lacking.
The brown alga Macrocystis represents a good model for dispersal as: it forms kelp rafts that may travel long distances (up to 900 km); and it has been reported that kelp rafts are capable of reproduction after detachment. Currently, four species of Macrocystis are recognized based on morphology (i.e. holdfast morphology and blade corrugation). Despite their ecological and economic importance, Macrocystis phylogeny and taxonomy remains unresolved.
We examined the phylogeography and taxonomy of Macrocystis collected in more than 80 sites around the world. Samples were analyzed using mitochondrial markers and microsatellites. Our results support previous suggestions that Macrocystis should be recognized as a mono-specific genus. Results also reveal shared haplotypes in several sites around the Southern Hemisphere and very low variability between samples, suggesting that kelp rafts may indeed represent an important mechanism for dispersal and connectivity.
