Chapter 8
Fluid Dynamics in Seagrass Ecology—from Molecules
to Ecosystems
Evamaria W. Koch*
Horn Point Laboratory, University of Maryland Center for Environmental Science,
P.O. Box 775, Cambridge, MD 21613, USA
Joseph D. Ackerman
Faculty of Environmental Sciences & Departments of Botany and Zoology,
University of Guelph, Guelph, ON, Canada N1G 2W1;
email: ackerman@uoguelph.ca
Jennifer Verduin
School of Biological Sciences & Biotechnology, Murdoch University, Murdoch WA 6150,
Australia; email: j.verduin@murdoch.edu.au
Michael van Keulen
School of Biological Sciences & Biotechnology, Murdoch University, Murdoch WA 6150,
Australia; email: keulen@mail.murdoch.edu.au
I. Introduction
Fluid dynamics is the study of the movement of fluids. Among other things, it addresses velocity, acceleration, and the forces exerted by or upon fluids in
motion (Daugherty et al., 1985; White, 1999; Kundu
and Cohen, 2002). Fluid dynamics affects every aspect of the existence of seagrasses from the smallest
to the largest scale: from the nutrients they obtain
to the sediment they colonize; from the pollination
of their flowers to the import/export of organic matter to adjacent systems; from the light that reaches
their leaves to the organisms that live in the seagrass habitats. Therefore, fluid dynamics is of major
importance in seagrass biology, ecology, and ecophysiology. Unfortunately, fluid dynamics is often
overlooked in seagrass systems (Koch, 2001). This
∗ Author for correspondence, email: koch@hpl.umces.edu
chapter provides a general background in fluid dynamics and then addresses increasingly larger scales
of fluid dynamic processes relevant to seagrass ecology and physiology: molecules (µm), leaves and
shoots (mm to cm), seagrass canopies (m), seagrass landscapes (100–1,000 m), and seagrasses as
part of the biosphere (>1,000 m). Although gases
are also fluids, this chapter is restricted to water
(i.e. compressed fluids), how it flows through seagrasses, the forces it exerts on the plants, and the
implications that this has for seagrass systems. Seagrasses are not only affected by water in motion,
they also affect the currents, waves and turbulence
of the water masses surrounding them. This capacity to alter their own environment is referred to as
“ecosystem engineering” (Jones et al., 1994, 1997;
Thomas et al., 2000). Readers are also encouraged
to consult a recent review by Okubo et al. (2002)
for a discussion on flow in terrestrial and aquatic
193–225.
A. W. D. Larkum et al. (eds.), Seagrasses: Biology, Ecology and Conservation, pp.
c
2006 Springer. Printed in the Netherlands.
Fluid Dynamics in Seagrass Ecology—from Molecules
to Ecosystems
Evamaria W. Koch*
Horn Point Laboratory, University of Maryland Center for Environmental Science,
P.O. Box 775, Cambridge, MD 21613, USA
Joseph D. Ackerman
Faculty of Environmental Sciences & Departments of Botany and Zoology,
University of Guelph, Guelph, ON, Canada N1G 2W1;
email: ackerman@uoguelph.ca
Jennifer Verduin
School of Biological Sciences & Biotechnology, Murdoch University, Murdoch WA 6150,
Australia; email: j.verduin@murdoch.edu.au
Michael van Keulen
School of Biological Sciences & Biotechnology, Murdoch University, Murdoch WA 6150,
Australia; email: keulen@mail.murdoch.edu.au
I. Introduction
Fluid dynamics is the study of the movement of fluids. Among other things, it addresses velocity, acceleration, and the forces exerted by or upon fluids in
motion (Daugherty et al., 1985; White, 1999; Kundu
and Cohen, 2002). Fluid dynamics affects every aspect of the existence of seagrasses from the smallest
to the largest scale: from the nutrients they obtain
to the sediment they colonize; from the pollination
of their flowers to the import/export of organic matter to adjacent systems; from the light that reaches
their leaves to the organisms that live in the seagrass habitats. Therefore, fluid dynamics is of major
importance in seagrass biology, ecology, and ecophysiology. Unfortunately, fluid dynamics is often
overlooked in seagrass systems (Koch, 2001). This
∗ Author for correspondence, email: koch@hpl.umces.edu
chapter provides a general background in fluid dynamics and then addresses increasingly larger scales
of fluid dynamic processes relevant to seagrass ecology and physiology: molecules (µm), leaves and
shoots (mm to cm), seagrass canopies (m), seagrass landscapes (100–1,000 m), and seagrasses as
part of the biosphere (>1,000 m). Although gases
are also fluids, this chapter is restricted to water
(i.e. compressed fluids), how it flows through seagrasses, the forces it exerts on the plants, and the
implications that this has for seagrass systems. Seagrasses are not only affected by water in motion,
they also affect the currents, waves and turbulence
of the water masses surrounding them. This capacity to alter their own environment is referred to as
“ecosystem engineering” (Jones et al., 1994, 1997;
Thomas et al., 2000). Readers are also encouraged
to consult a recent review by Okubo et al. (2002)
for a discussion on flow in terrestrial and aquatic
193–225.
A. W. D. Larkum et al. (eds.), Seagrasses: Biology, Ecology and Conservation, pp.
c
2006 Springer. Printed in the Netherlands.