GENETIC STRUCTURE IN POPULATIONS OF FUCUS VESICULOSUS (PHAEOPHYCEAE) OVER SPATIAL SCALES FROM 10 M TO 800 KM¹

Abstract

Recent studies showing consequences of species' genetic diversity on ecosystem performance raise the concern of how key ecosystem species are genetically structured. The bladder wrack Fucus vesiculosus L. is a dominant species of macroalga in the northern Atlantic, and it is particularly important as a habitat-forming species in the Baltic Sea. We examined the genetic structure of populations of F. vesiculosus with a hierarchical approach from a within-shore scale (10 m) to a between-seas scale (Baltic Sea-Skagerrak, 800 km). Analysis of five microsatellite loci showed that population differentiation was generally strong (average F ST = 12%), being significant at all spatial scales investigated (10 1 , 10 3 , 10 4-5 , 10 6 m). Genetic differentiation between seas (Baltic Sea and Skagerrak) was substantial. Nevertheless, the effects of isolation by distance were stronger within seas than between seas. Notably, Baltic summer-reproducing populations showed a strong within-sea, between-area (70 km) genetic structure, while Baltic autumnreproducing populations and Skagerrak summerreproducing populations revealed most genetic diversity between samples within areas (<1 km). Despite such differences in overall structure, Baltic populations of summer-and autumnreproducing morphs did not separate in a cluster analysis, indicating minor, if any, barriers to gene flow between them. Our results have important implications for management and conservation of F. vesiculosus, and we raise a number of concerns about how genetic variability should be preserved within this species.

Development and characterization of 35 single nucleotide polymorphism markers for the brown algaFucus vesiculosus

“…Some of the markers also showed levels of expected heterozygosity similar to those reported in microsatellitebased studies for the same species Perrin et al, 2007;Tatarenkov et al, 2007;Billard et al, 2010).…”

Connectivity among fragmented populations of a habitat-forming alga, Phyllospora comosa (Phaeophyceae, Fucales) on an urbanised coast

“…) on the east coast of Australia, as well as in macroalgae in other parts of the world (e.g. Tatarenkov et al 2007).…”

“…on the east coast of Australia, as well as in macroalgae in other parts of the world (e.g. Tatarenkov et al 2007).As with other fucoid algae (e.g. Kropf 1992, Coleman & Brawley 2005b), propagules of Phyllospora are likely to settle and attach quickly following release, particularly in relatively warm seawater temperatures on the east coast of NSW.…”

190 Years of Sargassum Taxonomy, Facing the Advent of DNA Phylogenies

“…Agardh, 1820;Montagne, 1845). Nowadays, the world has been more extensively explored and phycologists study the morphological and molecular variability of populations based on tens of specimens collected at various geographical levels (Tatarenkov et al, 2007;Zhao et al, 2007;Cheang et al, 2008), sequence genomes (Oudot-Le Secq et al, 2002Secq et al, , 2006, and attempt to identify species with genetic barcodes (Saunders, 2005;Robba et al, 2006;Chase et al, 2007).…”