Fundamental of Aquatic Ecology, Second Edition

271 Pages·1991·4.47 MB·English

FUNDAMENTALS OF
AQUATIC ECOLOGY
Fundamental of Aquatic Ecology, Second Edition
Edited by R. S. K. Barnes and K. H. Mann
© 1991 Blackwell Science Ltd. ISBN: 978-0-632-02983-9

Contents
Contributors,vi 8 Reproduction, LifeHistoriesandDispersal,
145
Preface,vii R.S.K. BARNES
Part1: Introduction 9 Speciation andBiogeography, 172
J.H.R. GEE
Organismsand Ecosystems,3
K.H. MANN
10 SpecialistAquaticFeedingMechanisms,186
J.H.R. GEE
Part2: AquaticEcosystems
2 EcologyofWaterColumns,29
Part4:HabitatTypesPeculiarto
I. VALIELA
AquaticSystems
3 EcologyofCoastalEcosystems,57
11 Reefs,213
I. VALIELA
R.N. HUGHES
4 EcologyofDeep-waterZones,77
12 Streamsand Rivers: One-way FlowSystems,
B.T. HARGRAVE
230
5 Lakesand OceansasFunctionalWholes, 91 M.J. WINTERBOURN & C.R. TOWNSEND
D.W. SCHINDLER
Part5: HumanEffects
6 AquaticEcosystemsandGlobalEcology, 108
D.W. SCHINDLER 13 ImpactsofMan'sActivitieson
AquaticSystems,245
Part3:AquaticIndividualsand Communities B.T. HARGRAVE
7 CommunityOrganization inMarineand
FreshwaterEnvironments,125 Index,265
C.R. TOWNSEND
V
Contributors
R.S.K. BARNESDepartmentofZoology. University D.W. SCHINDLERDepartmentsofZoologyand
ofCambridge,Cambridge, UK Botauy, UniversityofAlberta,Edmonton, Alberta,
Canada
J.H.R. GEEDepartmentofZoology, University
CollegeofWales, Aberystwyth,UK C.R, TOWNSEN0 DepartmentofZoology.
UuiversityofOtago, Dlmediu.NewZealand
B.T. HARGRAVEDepartmentofFIsheriesand
Oceans,BedfordlustituteofOceanography,Dartmouth, I. VALIELABostou UuiversityMariueProgram,
NovaScotia,Canada MarmeBIOlogicalLaboratory,WoodsHole,
Massachusetts, USA
R.N. HUGHESSchoolofBiologicalSetences,
UniversityCollegeofNorth Wales, Bangor, UK M,J. WINTERBOURN DepartmentofZoology,
UmversltyofCauterbury,ChrIStchurch,NewZealaud
K.H. MANN DepartmentofFisheriesandOceans,
BedfordlmtituteofOceanography,Dartmouth,Nova
Scotia,Canada
VI
Preface
In origin, this book is the second edition of our cerned with continental waters. If a chapter was
earlier Fundamentals of Aquatic Ecosystems written in the first instance by someone mainly
(1980). We decided, however, not simply to up with marine interests (as half were), then it was
date the first edition, but to modify this earlier ghosted/refereed by a member of the writing team
book in two major respects - the effect of this specializing in freshwater systems, and vice versa.
was to cause the second edition to depart so far We hope that both these innovations have led to
from the first as to become a completely different a more balanced approach and to a book that
and new book: hence the new title. Firstly, we describes exactly what its title indicates.
felt that integration of the various chapters into We are most grateful to our seven colleagues
a single book - always a problem in multi for sticking closely to the briefs that we supplied,
authored works - would be improved if fewer in respect of both writing and ghosting their vari
authors were involved in the project; and, sec ous chapters, and to Simon Rallison and Susan
ondly, we endeavoured to make each chapter Sternberg of Blackwell Scientific Publications for
more inclusive of all types of aquatic habitat and support and encouragement.
more truly 'aquatic' by having it drafted by two
R.S.K.B.
authors, one a marine biologist and the other con-
K.H.M.
VII
PART 1
INTRODUCTION
Fundamental of Aquatic Ecology, Second Edition
Edited by R. S. K. Barnes and K. H. Mann
© 1991 Blackwell Science Ltd. ISBN: 978-0-632-02983-9
1
Organisms and Ecosystems
K.H. MANN
Density relationships are also important. Again,
1.1 INTRODUCTION
pure water is the standard, with a maximum den
The term aquatic habitat covers a whole spectrum sityof1000kgm-3. Itreachesthisdensity ata tem
from the world's oceans to the bays and estuaries perature close to 4°e. As it is warmed above this
around their fringes, from major lakes (including temperatureit becomes lighter, but it also becomes
inland salt seas) tosmall ponds and to the marshes lighter as it cools between 4°C and its freezing
and swamps that are often found associated with point, at O°e. This is of critical importance for
them. It also includes rivers characterized by a preserving an ice-free environment in a lake or
one-way flow from the uplands, where they were pond. Suppose the weather is getting colder and
fed by rainfall and springs, to their junctions with the surface ofa lake is cooling from about 10°Cto
the sea at estuaries. At first sight these habitats 4°e. The density of the surface water is increasing
may seem so diverse that it is not sensible to try so it sinks through the layers below and convective
to discuss their ecology in one volume. However, mixing occurs. The lake may eventually have a
we hope to show that there are many processes uniform temperature and density from top to bot
that occur in all these types of environment, and tom. If the surface cooling process continues, the
that there is a fundamental unity between them. surface water may drop to 3°C, but instead of be
coming more dense, the water now becomes less
dense, and floats at the surface. Convective mixing
1.2 THE SPECIAL PROPERTIES
no longer occurs and freezing of the lower layers
OF WATER
is delayed. Once the surface temperature reaches
All living organisms contain a large proportion O°C, ice forms, with a density about 8% lower
of water, and life as we know it would not be than that of the water. It remains at the surface
possible if it were not for the special properties and still further delays freezing of the water be
of that water. For example, its specific heat is low. In this way, lakes of moderate depth retain
very high; that is to say, for a given input of heat, a lower layer of unfrozen water in which plants
its temperature changes relatively little. Pure and animals can survive the coldest winters.
water is taken as the standard, so that 1 calorie Saltcontentdepressesthe freezingpointofwater.
(4.17 joules) raises the temperature of 1 gram of For sea water with a salt content of 35%, the
water by 1 degree Celsius (i.e. the specific heat freezing point is -1.91°e. However, the tem
is 4.17]g-I°C-I), Most other substances in the perature of maximum density is also changed,
biosphere, such as the common rocks, have a and as salt water cools towards its freezing point
temperature rise of about SOC for an input of it becomes progressively more dense, so that con
4.17] (i.e. a specific heat of 0.83]g-IOC-1). vective sinking occurs continuously. The oceans
Hence, water forms a valuable buffer against are prevented from freezing by their sheer volume,
changing environmental temperature, both for ceaseless movement (driven by wind and tides)
the water within organisms and for the aquatic and convective currents, not by the special density
environment. properties found in fresh water.
Fundamental of Aquatic Ecology, Second Edition 3
Edited by R. S. K. Barnes and K. H. Mann
© 1991 Blackwell Science Ltd. ISBN: 978-0-632-02983-9