Bibliography
Murray, R. K., Bender, D. A., Botham, K. M., Kennelly, P. J.,
Rodwell, V. W., Weil, P. A., and Mayes, P. A., 2009.
Micronutrients: Vitamins & Minerals. Harper’s Illustrated
Biochemistry (28th ed.). New York: McGraw-Hill. Retrieved
January 4, 2012.
Reimer, K. J., Koch, I., and Cullen, W. R., 2010. Organoarsenicals.
Distribution and transformation in the environment. Metal Ions
in Life Sciences (Cambridge: RSC Publishing), 7, 165–229.
TROPHIC DYNAMICS
Xchel Moreno-Sánchez
1
, Andrés Abitia-Cárdenas
1
,
Juan M. Rodríguez-Baron
2
, Mónica Lara Uc
2 and
Rafael Riosmena-Rodríguez
2
1
Instituto Politécnico Nacional CICIMAR-IPN, La Paz,
BCS, Mexico
2
Programa de Investigación en Botãnica Marina,
Departamento Académico de Biología Marina,
Universidad Autónoma de Baja California Sur, La Paz,
Baja California Sur, Mexico
Synonyms
Trophic structure; Trophic web
Definition
Trophic dynamics is the basic process of transference
of energy from one trophic level to the next in an
ecosystem.
Introduction
The basic process of energy transfer in ecosystems occurs
through trophic dynamics (Lindeman, 1942). Trophic
dynamics in tropical and subtropical estuarine and coastal
marine ecosystems are characterized by a broad heterogeneity, which is determined by highly diverse biological
communities and complex trophic webs with a high
degree of interaction (Manickchand-Heileman et al.,
1998). The dynamic nature of trophic web interactions
and the variation in structure and function of several
coastal systems (including estuaries) are well known.
From the time of naturalists to the present-day ecologists, there has been an enormous interest in understanding energy transfer in ecosystems, and research has
increased notably since Lindeman (1942) coined the concept of trophic dynamics. This concept, along with the
articles published by Odum, fostered a rapid progress of
the use of the laws of thermodynamics in ecological
studies.
Estuarine trophic dynamics
Trophic dynamics have been widely studied in estuaries,
especially within the ichthyological community, but the
role of other biological components in the flow of energy
toward different trophic levels has only been suggested.
Estuaries are habitats with an exceptional primary productivity that allows them to support a high abundance and
biomass of fish; they are essential habitats in the life cycle
of several teleosts, functioning as feeding, reproduction,
and refuge areas. Fish communities in estuaries are very
dynamic due to seasonal changes in abiotic factors: currents, water temperature, pH, freshwater inputs, evaporation, precipitation, and drastic changes in salinity. These
changing and extreme conditions result in estuaries being
characterized by few dominant fish species that are resident or typical of these areas. These species are classified
as anadromous (fish that migrate from salt water to freshwater to reproduce) or catadromous (fish that migrate from
freshwater to salt water to reproduce) (Kennish, 1990).
The trophic dynamics of estuaries are determined
mainly by the trophic relationships of all biological components. The movement of nutrients between estuaries
and marine communities occurs through the biota in
a predictable sequence of trophic relations (nutrients).
The trophic structure of communities is centered on the
concept of the trophic web, which is the result of branched
and/or linked trophic chains. It can be defined as the sum
of all chains, with organisms grouped in categories or trophic levels, which consist of producers, consumers, and
decomposers. These in turn are responsible for energy
transfer. Therefore, at the base of the trophic chain are all
the autotrophic organisms which fixate carbon through
photosynthesis and provide energy to the primary consumers (heterotrophs) and so on through the upper trophic
levels. Primary consumers serve as food for secondary
consumers (herbivores), and these are a source of food
for tertiary consumers (carnivores). Decomposers
(saprophytic bacteria and fungi) assimilate dead plant
and animal matter, transforming it in organic matter to
get energy, while they release mineral nutrients that primary producers (autotrophs) use for growth. At each trophic level, approximately 80–90 % of potential energy is
lost as heat, and this is a limiting factor that restricts trophic chain lengths to three to four trophic levels.
Estuarine trophic dynamic processes
The feeding habits of fish are important for several reasons. First, they reveal the trophic relations of the different
species and indirectly bring to light aspects of the energy
flow in estuarine communities. Second, they reveal the
ecological relations between organisms, which can be
used to better interpret the general dynamics of estuaries
and to make recommendations for the appropriate administration of fisheries resources. The functioning of estuarine and coastal marine ecosystems depends mostly on
using an external source of energy, solar radiation.
A portion of this incident energy is transformed by photosynthetic processes (primary production) carried out by
the phytoplankton (such as diatoms, dinoflagellates,
coccolithophorids, cyanophytes, and silicoflagellates)
718
TROPHIC DYNAMICS
Murray, R. K., Bender, D. A., Botham, K. M., Kennelly, P. J.,
Rodwell, V. W., Weil, P. A., and Mayes, P. A., 2009.
Micronutrients: Vitamins & Minerals. Harper’s Illustrated
Biochemistry (28th ed.). New York: McGraw-Hill. Retrieved
January 4, 2012.
Reimer, K. J., Koch, I., and Cullen, W. R., 2010. Organoarsenicals.
Distribution and transformation in the environment. Metal Ions
in Life Sciences (Cambridge: RSC Publishing), 7, 165–229.
TROPHIC DYNAMICS
Xchel Moreno-Sánchez
1
, Andrés Abitia-Cárdenas
1
,
Juan M. Rodríguez-Baron
2
, Mónica Lara Uc
2 and
Rafael Riosmena-Rodríguez
2
1
Instituto Politécnico Nacional CICIMAR-IPN, La Paz,
BCS, Mexico
2
Programa de Investigación en Botãnica Marina,
Departamento Académico de Biología Marina,
Universidad Autónoma de Baja California Sur, La Paz,
Baja California Sur, Mexico
Synonyms
Trophic structure; Trophic web
Definition
Trophic dynamics is the basic process of transference
of energy from one trophic level to the next in an
ecosystem.
Introduction
The basic process of energy transfer in ecosystems occurs
through trophic dynamics (Lindeman, 1942). Trophic
dynamics in tropical and subtropical estuarine and coastal
marine ecosystems are characterized by a broad heterogeneity, which is determined by highly diverse biological
communities and complex trophic webs with a high
degree of interaction (Manickchand-Heileman et al.,
1998). The dynamic nature of trophic web interactions
and the variation in structure and function of several
coastal systems (including estuaries) are well known.
From the time of naturalists to the present-day ecologists, there has been an enormous interest in understanding energy transfer in ecosystems, and research has
increased notably since Lindeman (1942) coined the concept of trophic dynamics. This concept, along with the
articles published by Odum, fostered a rapid progress of
the use of the laws of thermodynamics in ecological
studies.
Estuarine trophic dynamics
Trophic dynamics have been widely studied in estuaries,
especially within the ichthyological community, but the
role of other biological components in the flow of energy
toward different trophic levels has only been suggested.
Estuaries are habitats with an exceptional primary productivity that allows them to support a high abundance and
biomass of fish; they are essential habitats in the life cycle
of several teleosts, functioning as feeding, reproduction,
and refuge areas. Fish communities in estuaries are very
dynamic due to seasonal changes in abiotic factors: currents, water temperature, pH, freshwater inputs, evaporation, precipitation, and drastic changes in salinity. These
changing and extreme conditions result in estuaries being
characterized by few dominant fish species that are resident or typical of these areas. These species are classified
as anadromous (fish that migrate from salt water to freshwater to reproduce) or catadromous (fish that migrate from
freshwater to salt water to reproduce) (Kennish, 1990).
The trophic dynamics of estuaries are determined
mainly by the trophic relationships of all biological components. The movement of nutrients between estuaries
and marine communities occurs through the biota in
a predictable sequence of trophic relations (nutrients).
The trophic structure of communities is centered on the
concept of the trophic web, which is the result of branched
and/or linked trophic chains. It can be defined as the sum
of all chains, with organisms grouped in categories or trophic levels, which consist of producers, consumers, and
decomposers. These in turn are responsible for energy
transfer. Therefore, at the base of the trophic chain are all
the autotrophic organisms which fixate carbon through
photosynthesis and provide energy to the primary consumers (heterotrophs) and so on through the upper trophic
levels. Primary consumers serve as food for secondary
consumers (herbivores), and these are a source of food
for tertiary consumers (carnivores). Decomposers
(saprophytic bacteria and fungi) assimilate dead plant
and animal matter, transforming it in organic matter to
get energy, while they release mineral nutrients that primary producers (autotrophs) use for growth. At each trophic level, approximately 80–90 % of potential energy is
lost as heat, and this is a limiting factor that restricts trophic chain lengths to three to four trophic levels.
Estuarine trophic dynamic processes
The feeding habits of fish are important for several reasons. First, they reveal the trophic relations of the different
species and indirectly bring to light aspects of the energy
flow in estuarine communities. Second, they reveal the
ecological relations between organisms, which can be
used to better interpret the general dynamics of estuaries
and to make recommendations for the appropriate administration of fisheries resources. The functioning of estuarine and coastal marine ecosystems depends mostly on
using an external source of energy, solar radiation.
A portion of this incident energy is transformed by photosynthetic processes (primary production) carried out by
the phytoplankton (such as diatoms, dinoflagellates,
coccolithophorids, cyanophytes, and silicoflagellates)
718
TROPHIC DYNAMICS