Chapter 2
Seagrass Evolution, Ecology and Conservation:
A Genetic Perspective
Michelle Waycott*
School of Tropical Biology, James Cook University, Townsville, Qld 4811, Australia
Gabriele Procaccini
Stazione Zoologica ‘A. Dohrn’, Laboratorio di Ecologia del Benthos,
Punta S. Pietro, 80077 Ischia (Napoli), Italy
Donald H. Les
Department of Ecology and Evolutionary Biology, The University of Connecticut,
75 North Eagleville Road, U-43, Storrs, CT 06269-3043, USA
Thorsten B. H. Reusch
Max-Planck-Institut f ¨
ur Limnologie, August-Thienemann-Street 2, 24306 Pl ¨
on, Germany
I. Introduction
The study and characterization of natural systems
involves the evaluation of their diversity and the
identification and definition of processes and fluxes
operating at different temporal and spatial scales.
Ecological studies in general are limited by their
ability to infer these different scales of process.
The use of genetic analysis to provide insight into
scales of process in ecology has increased as the basic tools to undertake such studies have improved
and become more widely available. A large number
of genetic based approaches are available today but
most commonly utilized are DNA markers to assess
the relationships among individuals at hierarchical
levels ranging from fine scale population processes
to the phylogenetic relationships of species, genera,
and higher taxa. To date, most studies of seagrass
genetic diversity have been aimed toward the comprehension of ecological and evolutionary processes
and, as such, this is the main subject of this chapter.
∗ Author for correspondence, email:michelle.waycott@jcu.edu.au
However, we also provide insight into how seagrass
genetic diversity can be assessed and utilized for
biodiversity conservation, although the use of this
approach has been very limited to date (Waycott,
2000a). As genetic diversity data provide insight into
such an array of evolutionary and ecological processes it represents valuable information for conservation management strategies (e.g. Ehrlich and
Wilson, 1991; Faith, 1994; Moritz and Faith, 1998).
The widespread use of genetic data in conservation
(e.g. Frankel and Soule, 1981; Frankel et al., 1995;
Holsinger et al., 1999; Frankham et al., 2002) has
allowed dramatic improvement in our ability to interpret patterns of genetic diversity in this context.
Seagrasses represent difficult ecological subjects
in marine ecosystems. The biology of seagrasses is
constrained by the environment they inhabit leading to convergence in morphologies. For example the majority of seagrass species possess flexible strap-like leaves (den Hartog, 1970), although
they do not represent a single evolutionary lineage (Les et al., 1997). This leaf form allows the
plants to thrive in their fluidic, tide- and wave-driven
25–50.
A. W. D. Larkum et al. (eds.), Seagrasses: Biology, Ecology and Conservation, pp.
c
2006 Springer. Printed in the Netherlands.
Seagrass Evolution, Ecology and Conservation:
A Genetic Perspective
Michelle Waycott*
School of Tropical Biology, James Cook University, Townsville, Qld 4811, Australia
Gabriele Procaccini
Stazione Zoologica ‘A. Dohrn’, Laboratorio di Ecologia del Benthos,
Punta S. Pietro, 80077 Ischia (Napoli), Italy
Donald H. Les
Department of Ecology and Evolutionary Biology, The University of Connecticut,
75 North Eagleville Road, U-43, Storrs, CT 06269-3043, USA
Thorsten B. H. Reusch
Max-Planck-Institut f ¨
ur Limnologie, August-Thienemann-Street 2, 24306 Pl ¨
on, Germany
I. Introduction
The study and characterization of natural systems
involves the evaluation of their diversity and the
identification and definition of processes and fluxes
operating at different temporal and spatial scales.
Ecological studies in general are limited by their
ability to infer these different scales of process.
The use of genetic analysis to provide insight into
scales of process in ecology has increased as the basic tools to undertake such studies have improved
and become more widely available. A large number
of genetic based approaches are available today but
most commonly utilized are DNA markers to assess
the relationships among individuals at hierarchical
levels ranging from fine scale population processes
to the phylogenetic relationships of species, genera,
and higher taxa. To date, most studies of seagrass
genetic diversity have been aimed toward the comprehension of ecological and evolutionary processes
and, as such, this is the main subject of this chapter.
∗ Author for correspondence, email:michelle.waycott@jcu.edu.au
However, we also provide insight into how seagrass
genetic diversity can be assessed and utilized for
biodiversity conservation, although the use of this
approach has been very limited to date (Waycott,
2000a). As genetic diversity data provide insight into
such an array of evolutionary and ecological processes it represents valuable information for conservation management strategies (e.g. Ehrlich and
Wilson, 1991; Faith, 1994; Moritz and Faith, 1998).
The widespread use of genetic data in conservation
(e.g. Frankel and Soule, 1981; Frankel et al., 1995;
Holsinger et al., 1999; Frankham et al., 2002) has
allowed dramatic improvement in our ability to interpret patterns of genetic diversity in this context.
Seagrasses represent difficult ecological subjects
in marine ecosystems. The biology of seagrasses is
constrained by the environment they inhabit leading to convergence in morphologies. For example the majority of seagrass species possess flexible strap-like leaves (den Hartog, 1970), although
they do not represent a single evolutionary lineage (Les et al., 1997). This leaf form allows the
plants to thrive in their fluidic, tide- and wave-driven
25–50.
A. W. D. Larkum et al. (eds.), Seagrasses: Biology, Ecology and Conservation, pp.
c
2006 Springer. Printed in the Netherlands.