vi
Foreword
is, they collect and integrate information from studies scattered in diverse journals, a pragmatic service in our era of burgeoning data and reports. More important perhaps, they provide critical evaluations and interpretations of existing data
and explore interrelationships among biotic components of the ecosystem as a
whole. Such analyses produce new insights that instill vigor and new directions
into a discipline.
This text begins with summaries of some of the prevalent lipid compounds in
freshwater ecosystems, produced within the aquatic systems and imported from
the catchment areas. It then presents selected methodology for differentiation of
lipid classes and fatty acids. Certain fatty acids have sufficient source specificity
that they can be utilized as biochemical and trophic markers. With careful interpretation, such markers can provide qualitative insights into trophic relationships
at higher levels in the food web.
Examination of environmental factors controlling synthesis of lipids in algae
provides insights into their usefulness as indicators of the physiological status of
the algae. Because zooplankton and probably most consumer organisms are capable of little de novo synthesis, lipids are primarily dietary in origin. Fluctuations in
lipid content and quality in food sources, as well as feeding behaviors, are thus
critically important to subsequent development, growth, and reproductive success
of higher aquatic organisms. Differences in lipid requirements, utilization, and
storage strategies among biota, particularly invertebrates and fish, can potentially
influence evolutionary pathways, competitive interactions, and biodiversity.
The impacts of human activities on freshwater ecosystems are now so pervasive
that they influence most biogeochemical cycling. Many nonpolar organic contaminants bioaccumulate in lipid compounds. Understanding of biochemical and
environmental factors regulating bioaccumulation and cycling is therefore essential to freshwater management and remediation. Finally, hydrophobicity of lipids
results in an accumulation of natural and anthropogenic compounds into lipid-rich
tissues of organisms, water-surface microlayers, and foams. Numerous microbes
and higher organisms have life stages that, during particular periods, inhabit the
surface regions and thus are exposed to potentially elevated concentrations of
lipid-associated contaminants. Study of this complex community is still in its
infancy.
This book is a comprehensive summary of the status of our knowledge of the
multifarious roles of lipids in freshwater ecosystems. Although gaps in our understanding still remain, the authors raise questions that will give impetus to accelerated experimental research in this exciting and essential area of inquiry.
Robert G. Wetzel
Bishop Professor of Biological Sciences
University of Alabama
Foreword
is, they collect and integrate information from studies scattered in diverse journals, a pragmatic service in our era of burgeoning data and reports. More important perhaps, they provide critical evaluations and interpretations of existing data
and explore interrelationships among biotic components of the ecosystem as a
whole. Such analyses produce new insights that instill vigor and new directions
into a discipline.
This text begins with summaries of some of the prevalent lipid compounds in
freshwater ecosystems, produced within the aquatic systems and imported from
the catchment areas. It then presents selected methodology for differentiation of
lipid classes and fatty acids. Certain fatty acids have sufficient source specificity
that they can be utilized as biochemical and trophic markers. With careful interpretation, such markers can provide qualitative insights into trophic relationships
at higher levels in the food web.
Examination of environmental factors controlling synthesis of lipids in algae
provides insights into their usefulness as indicators of the physiological status of
the algae. Because zooplankton and probably most consumer organisms are capable of little de novo synthesis, lipids are primarily dietary in origin. Fluctuations in
lipid content and quality in food sources, as well as feeding behaviors, are thus
critically important to subsequent development, growth, and reproductive success
of higher aquatic organisms. Differences in lipid requirements, utilization, and
storage strategies among biota, particularly invertebrates and fish, can potentially
influence evolutionary pathways, competitive interactions, and biodiversity.
The impacts of human activities on freshwater ecosystems are now so pervasive
that they influence most biogeochemical cycling. Many nonpolar organic contaminants bioaccumulate in lipid compounds. Understanding of biochemical and
environmental factors regulating bioaccumulation and cycling is therefore essential to freshwater management and remediation. Finally, hydrophobicity of lipids
results in an accumulation of natural and anthropogenic compounds into lipid-rich
tissues of organisms, water-surface microlayers, and foams. Numerous microbes
and higher organisms have life stages that, during particular periods, inhabit the
surface regions and thus are exposed to potentially elevated concentrations of
lipid-associated contaminants. Study of this complex community is still in its
infancy.
This book is a comprehensive summary of the status of our knowledge of the
multifarious roles of lipids in freshwater ecosystems. Although gaps in our understanding still remain, the authors raise questions that will give impetus to accelerated experimental research in this exciting and essential area of inquiry.
Robert G. Wetzel
Bishop Professor of Biological Sciences
University of Alabama