Genetic structure of eelgrass Zostera marina meadows in an embayment with restricted water flow

Marine Ecology Progress Series
By: , and 

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Abstract

Genetic structure of the seagrass Zostera marina in a coastal lagoon with restricted water flow, and with heterogeneous water residence times and oceanographic characteristics, was assessed using 8 polymorphic microsatellite loci. Analyses of genetic differentiation (θ) and Bayesian clustering suggested that the Z. marina population in San Quintin Bay (SQB) is genetically substructured, with at least 4 genetically different groups: (1) West Head, (2) Mouth, (3) East Arm, and (4) East Head. The greatest θ value was observed between the most distant sites (θ = 0.095). The lowest values were found among sites closest to the mouth of the coastal lagoon (θ = 0.000 to 0.009). The maximum likelihood approach showed that the sites at the mouth have a mixed pattern of gene flow without a unidirectional pattern. In contrast, there was a clear pattern of asymmetrical gene flow from the mouth towards the West Head. These results suggested that the restriction of water flow at the heads, current pattern, and the distance between sites can reduce genetic flow and promote genetic differences within Z. marina meadows in small water embayments such as SQB. Though the population is genetically substructured and a 14% decline in cover has been detected, this study did not show evidence of a recent genetic bottleneck. In contrast, mouth sites have experienced a recent expansion in their population size, and also perhaps a recent influx of rare alleles from genetically distinct immigrants

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Genetic structure of eelgrass Zostera marina meadows in an embayment with restricted water flow
Series title Marine Ecology Progress Series
DOI 10.3354/meps309107
Volume 309
Year Published 2006
Language English
Publisher Inter-Research
Contributing office(s) Alaska Science Center
Description 10 p.
First page 107
Last page 116
Online Only (Y/N) N
Additional Online Files (Y/N) N