Foreword
Although limnology is a young discipline, it has, over the past century, experienced marked growth. Its early descriptive period was a long one, given the
enormous diversity of biota and environments in freshwater ecosystems. With the
development of quantitative techniques came the ability to measure production
rates and other parameters and to demonstrate the effects of nutrient limitation and
predation on productivity and energy flow. As understanding of these phenomena
grew, so too did our appreciation of the many complex chemical interactions
among the biotic and habitat components of freshwater ecosystems.
A recent, exciting phase of limnology, which may be called biochemical limnology, is evolving rapidly. One of its many facets is the study of population and
community dynamics at basic physiological levels. Examples are many. The
integration of recent studies of food biochemistry with traditional studies of food
quantity has begun to reveal the striking importance of food quality to reproduction and to the growth dynamics of many aquatic animals. Positive as well as
negative alleleochemical interactions, already known in terrestrial ecosystems,
are emerging as a major factor of many competitive interactions in fresh waters.
The role of dissolved organic matter, particularly humic and fulvic compounds
of plant origin, in the aquatic ecosystem is complex. Not only do these compounds
function as large stores of carbon and energy, but they are also metabolically
interactive. For example, humic substances can complex with enzymes and other
metabolic macromolecules and become stored in inactivated states for various
periods of time. These complexes can then be displaced to other parts of the
ecosystem, potentially to be reactivated at a later time. Thus, chemical communication among biotic components is certainly as prevalent in freshwater ecosystems as it is in the complex metabolic biochemistry of metazoans. If we are to
manage freshwater ecosystems effectively, we must discover more about such
interactive control mechanisms. Those controls are chemical; therefore, understanding the biology requires an understanding of the biochemistry.
This collection of work on lipids represents a synthesis of existing information
on a diverse group of hydrophobic organic compounds of biological origin in
freshwater ecosystems: their origins, functional couplings among biotic and abiotic processes, and fates. Syntheses serve many functions. If done well, as this one
v
Although limnology is a young discipline, it has, over the past century, experienced marked growth. Its early descriptive period was a long one, given the
enormous diversity of biota and environments in freshwater ecosystems. With the
development of quantitative techniques came the ability to measure production
rates and other parameters and to demonstrate the effects of nutrient limitation and
predation on productivity and energy flow. As understanding of these phenomena
grew, so too did our appreciation of the many complex chemical interactions
among the biotic and habitat components of freshwater ecosystems.
A recent, exciting phase of limnology, which may be called biochemical limnology, is evolving rapidly. One of its many facets is the study of population and
community dynamics at basic physiological levels. Examples are many. The
integration of recent studies of food biochemistry with traditional studies of food
quantity has begun to reveal the striking importance of food quality to reproduction and to the growth dynamics of many aquatic animals. Positive as well as
negative alleleochemical interactions, already known in terrestrial ecosystems,
are emerging as a major factor of many competitive interactions in fresh waters.
The role of dissolved organic matter, particularly humic and fulvic compounds
of plant origin, in the aquatic ecosystem is complex. Not only do these compounds
function as large stores of carbon and energy, but they are also metabolically
interactive. For example, humic substances can complex with enzymes and other
metabolic macromolecules and become stored in inactivated states for various
periods of time. These complexes can then be displaced to other parts of the
ecosystem, potentially to be reactivated at a later time. Thus, chemical communication among biotic components is certainly as prevalent in freshwater ecosystems as it is in the complex metabolic biochemistry of metazoans. If we are to
manage freshwater ecosystems effectively, we must discover more about such
interactive control mechanisms. Those controls are chemical; therefore, understanding the biology requires an understanding of the biochemistry.
This collection of work on lipids represents a synthesis of existing information
on a diverse group of hydrophobic organic compounds of biological origin in
freshwater ecosystems: their origins, functional couplings among biotic and abiotic processes, and fates. Syntheses serve many functions. If done well, as this one
v