Freshwater Mussel Ecology: A Multifactor Approach to Distribution and Abundance (Freshwater Ecology Series)

217 Pages·2008·3.93 MB·English

by  David Lowell Strayer

freshwater mussel ecology
freshwater ecology series
Editor-in-Chief
F.Richard Hauer,Flathead Lake Biological Station,
University of Montana
Editorial Board
Emily S. Bernhardt, Department of Biology, Duke University
Stuart E. Bunn, Australian Rivers Institute, Griffith University, Australia
Clifford N. Dahm, Department of Biology, University of New Mexico
Kurt D. Fausch, Department of Fishery and Wildlife Biology,
Colorado State University
Anne E. Hershey, Biology Department, University of North Carolina, Greensboro
Peter R. Leavitt, Department of Biology, University of Regina, Canada
Mary E. Power, Department of Integrative Biology,
University of California, Berkeley
R. Jan Stevenson, Department of Zoology, Michigan State University
University of California Press Editor
Charles R. Crumly
http://www.ucpress.edu/books/pages/11082.html
FRESHWATER
MUSSEL ECOLOGY
A Multifactor Approach
to Distribution and Abundance
David L. Strayer
UNIVERSITY OF CALIFORNIA PRESS Berkeley Los Angeles London
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For more information, visit www.ucpress.edu.
Freshwater Ecology Series, volume 1
University of California Press
Berkeley and Los Angeles, California
University of California Press, Ltd.
London, England
©2008 by
The Regents of the University of California
Library of Congress Cataloging-in-Publication Data
Strayer, David Lowell, 1955–.
Freshwater mussel ecology : a multifactor approach
to distribution and abundance / David L. Strayer.
p. cm. — (Freshwater ecology series; v. 1)
Includes bibliographical references and index.
ISBN 978-0-520-25526-5 (cloth)
1. Freshwater mussels—Ecology. I. Title.
QL430.6.S8785 2008
594'.4176—dc22 2007043799
Manufactured in the United States of America
16 15 14 13 12 11 10 09 08
10 9 8 7 6 5 4 3 2 1
The paper used in this publication meets the
minimum requirements of ANSI/NISO
Z39.48-1992 (R 1997) (Permanence of Paper).(cid:2)(cid:2)
Cover illustration: A collection of pearly mussel
shells. Photo by Dr. Chris Barnhart.
contents
Preface vii
part one. the laboratory
1. The Model as Monster 3
2. The Case of Pearly Mussels 9
part two. the monster’s parts
3. Dispersal 25
4. Habitat 43
5. Hosts 65
6. Food 87
7. Enemies 105
8. Implications for Conservation 113
part three. making the monster walk
9. Three Models for Mussel Ecology 121
10. Is a Comprehensive Model Possible? 143
Literature Cited 157
Index 199

preface
I wrote this little book to try to solve a specific problem and at least shed
some light on, if not solve, a very general problem in ecology. The spe-
cific problem is understanding how ecological factors determine the dis-
tribution and abundance of pearly mussels (Unionoidea). Pearly mussels
are widespread and common in fresh waters around the world, and are of
special interest because of their conservation problems: human activities
have driven dozens of species into extinction and hundreds more into
danger of extinction. Furthermore, as dominant suspension-feeders and
shell-builders, pearly mussels play important roles in ecosystem function-
ing. Historically, pearly mussels have supported important fisheries for
pearls, mother-of-pearl, and meat, but many of these fisheries have been
destroyed by overharvest, habitat destruction, and pollution. Understand-
ing how ecological factors control pearly mussel populations would help
us to conserve or restore imperiled populations, understand the function-
ing of freshwater ecosystems, and manage mussel fisheries. At present, we
have many fragments of useful knowledge about pearly mussel ecology,
but we do not have a catalog of the pieces of information that will even-
tually be needed to produce an adequate theory of pearly mussel distri-
bution and abundance, nor do we have a plan for putting all of these pieces
together. There is good evidence to suspect that an adequate theory will
have to include multiple ecological factors, and I do not think that mussel
vii
ecologists have realized just how difficult the problem of integrating mul-
tiple factors into a single theory is likely to be.
The general problem that I will address here is that of integrating mul-
tiple factors into a single working theory. This problem is pervasive in
ecology, although it has not been widely recognized as a problem by ecol-
ogists. Although it could be argued that most important ecological vari-
ables are under the simultaneous control of multiple factors, most of
contemporary ecology still is concerned with the influence of a single fac-
tor (or occasionally two factors). As I will show below, and as is apparent
from cases such as the controversy over top-down “versus” bottom-upcon-
trol of plankton populations, integrating multiple controlling factors into
a satisfactory working theory is not a trivial problem. I believe that ecolo-
gists eventually will have to confront this general problem.
The goal of this book, therefore, is to try to develop a satisfactory,
multiple-factor theory to explain the distribution and abundance of pearly
mussels (or more fundamentally to assess whether it is even feasible to de-
velop such a theory at all), and to explore the general problem of multi-
factor theories. After presenting some basic information on the biology and
conservation situation of pearly mussels, I will consider in detail the var-
ious factors that might be included in a theory to understand the distri-
bution and abundance of pearly mussels, highlighting information gaps.
Finally, I will discuss various ways in which these pieces might be drawn
together into a theory, and make suggestions about approaches that might
be fruitful. I admit that my attempts at integration are not entirely suc-
cessful, but I think that they are partly successful, and may inspire others
to finish the job.
I wrote most of this book while a visitor in the Laboratoire d’Écologie
des Hydrosystèmes Fluviaux at the Université de Lyon 1. I am most grateful
to Janine Gibert, Bernhard Statzner, and their colleagues at the University
of Lyon for providing a pleasant and quiet place in which to think and
work, and for their personal kindness (merci beaucoup!). The Cary Institute
of Ecosystem Studies likewise has provided an atmosphere that encour-
ages reflection and synthesis. I thank Bernhard Statzner, Hugh Possingham,
Winsor Lowe, and my colleagues at the Cary Institute of Ecosystem Studies
for helpful discussions, and Kevin Cummings, Tom Watters, Art Bogan,
and Christine Mayer for maintaining the freshwater mollusk bibliogra-
phy and mussel/host database, which saved me a lotof work. Kaustav Roy
viii preface
generously shared his intruiging analysis of the relationship between mus-
sel body size and conservation status (Fig. 6), and Tom Watters and Martin
Huehner kindly supplied reports of their mussel surveys for Fig. 11. Lynn
Sticker helped check the references while at the same time attending to
a leaky roof. I thank the efficient and friendly people at the University of
California Press and Michael Bass Associates for their help in turning a
pile of loose pages into a book. I particularly appreciate Chuck Crumly’s
early enthusiasm and advice, and Scott Norton’s advice on chapter orga-
nization and headings. Finally, I appreciate the support of the Hudson
River Foundation, the National Science Foundation, the Nature Con-
servancy, the New York Natural Heritage Program, and the United States
Fish and Wildlife Service for funding my past work on mussel ecology.
preface ix