Conservation Genetics

, Volume 8, Issue 6, pp 1377–1391

Feed-backs between genetic structure and perturbation-driven decline in seagrass (Posidonia oceanica) meadows

  • Elena Diaz-Almela
  • Sophie Arnaud-Haond
  • Mirjam S. Vliet
  • Elvira Álvarez
  • Núria Marbà
  • Carlos M. Duarte
  • Ester A. Serrão
Research Article

DOI: 10.1007/s10592-007-9288-0

Cite this article as:
Diaz-Almela, E., Arnaud-Haond, S., Vliet, M.S. et al. Conserv Genet (2007) 8: 1377. doi:10.1007/s10592-007-9288-0
  • 181 Downloads

Abstract

We explored the relationships between perturbation-driven population decline and genetic/genotypic structure in the clonal seagrass Posidonia oceanica, subject to intensive meadow regression around four Mediterranean fish-farms, using seven specific microsatellites. Two meadows were randomly sampled (40 shoots) within 1,600 m2 at each site: the “impacted” station, 5–200 m from fish cages, and the “control” station, around 1,000 m downstream further away (considered a proxy of the pre-impact genetic structure at the site). Clonal richness (R), Simpson genotypic diversity (D*) and clonal sub-range (CR) were highly variable among sites. Nevertheless, the maximum distance at which clonal dispersal was detected, indicated by CR, was higher at impacted stations than at the respective control station (paired t-test: P < 0.05, N = 4). The mean number of alleles (Â) and the presence of rare alleles (Âr) decreased at impacted stations (paired t-test: P < 0.05, and P < 0.02, respectively, N = 4). At a given perturbation level (quantified by the organic and nutrient loads), shoot mortality at the impacted stations significantly decreased with CR at control stations (R= 0.86, P < 0.05). Seagrass mortality also increased with  (R= 0.81, P < 0.10), R (R= 0.96, P < 0.05) and D* (R= 0.99, P < 0.01) at the control stations, probably because of the negative correlation between those parameters and CR. Therefore, the effects of clonal size structure on meadow resistance could play an important role on meadow survival. Large genotypes of P. oceanica meadows thus seem to resist better to fish farm-derived impacts than little ones. Clonal integration, foraging advantage or other size-related fitness traits could account for this effect.

Keywords

Clonal sub-range Genetic diversity Population decline Genotypic diversity Fish-farm impacts 

Copyright information

© Springer Science+Business Media, Inc. 2007

Authors and Affiliations

  • Elena Diaz-Almela
    • 1
  • Sophie Arnaud-Haond
    • 2
  • Mirjam S. Vliet
    • 2
  • Elvira Álvarez
    • 3
  • Núria Marbà
    • 1
  • Carlos M. Duarte
    • 1
  • Ester A. Serrão
    • 2
  1. 1.Laboratorio de Ecología Litoral, Grupo de Oceanografía Interdisciplinar (G.O.I), IMEDEA (CSIC-UIB)EsporlesSpain
  2. 2.CCMAR, CIMAR – Laboratório Associado, F.C.M.A. – Univ. AlgarveFaroPortugal
  3. 3.Dirección General de Pescas, Comunidad de las Islas BalearesPalma de MallorcaSpain

Personalised recommendations