First pages of innovative articles. Ecology.
These are the first pages of the 4 articles on ecology. They were published in the journal entitled
Doklady Biological Sciences.
This journal is available in many of U.S. university libraries.
This journal publishes English translations of scientific papers that were originally published in Russian in the best scientific journal of Russian Academy of Sciences.
**
**
A New Type of Effect of Potentially Hazardous Substances:
Uncouplers of Pelagial–Benthal Coupling
S. A. Ostroumov
Presented by Academician V.L. Kas’yanov November 7, 2001
Received November 8, 2001
Moscow State University, Vorob’evy gory, Moscow,
119899 Russia
0012-4966/02/0304-0127$27.00 © 2002 MAIK “Nauka /Interperiodica”
Doklady Biological Sciences, Vol. 383, 2002, pp. 127–130.
Translated from Doklady Akademii Nauk, Vol. 383, No. 1, 2002, pp. 138–141.
Original Russian Text Copyright © 2002 by Ostroumov.
Hydrobionts are mediators of “biogenic migration
of atoms in the biosphere” [1]. This migration is partly
implemented in the framework of pelagial–benthal
coupling. Trophic activity of bottom filter feeders
results in consumption of the organic matter of plankton
synthesized in pelagic zones (see, e.g., [2]). Even
the organic matter that is not assimilated by fulter feeders
is involved in pelagial–benthal coupling. Suspended
matter of aquatic ecosystems (including pellets of
invertebrates) is subjected to gravitational sedimentation
[2, 3]. The pellets of invertebrates are formed as a
result of excretion of unassimilated and undigested
food of phytophagous invertebrates. The degree of food
assimilation in different taxa of invertebrates ranges
from 1 to 98% [4, 5]. The mean percentage of food
assimilability averaged over many groups of organisms
is 16.2–89.6% (Table 1). Therefore, the rest of the food
matter (10.4–83.8%) remains unassimilated and settles
to the bottom with pellets. Thus, pellets of invertebrates
are able to transport a fraction of organic matter synthesized
in the pelagic zone by photosynthetic organisms
from this zone to the bottom layers of aquatic ecosystems,
i.e., to the habitat of benthic organisms (the
benthal).
The goal of this work was to determine whether
there is a potential hazard of disturbance of the pelagial–
benthal coupling induced by water pollution. It
should be noted that such a hazard of the pollutioninduced
disturbance of ecosystems has been almost
entirely ignored thus far.
Bivalve mollusks were objects of this study.
Because bivalve mollusks are involved in elimination
and sedimentation of particles suspended in bulk water,
these organisms are components of the pelagial–
benthal coupling [6–11].
The effect of potassium bichromate, a xenobiotic,
on the rate of elimination of suspended particles by the
Black Sea mussel Mytilus galloprovincialis was studied.
Experimental methods were described elsewhere
[10, 11]. Mussels (kindly provided by of A.V. Pirkova
and A.Ya. Stolbov) were grown in water headers in the
outskirts of the city of Sevastopol. The mean body
weights (raw weights with shell) of experimental
(treated with potassium bichromate) and control mollusks
were 6.53 and 6.59 g, respectively. Both control
and experimental tanks contained 13 specimens of
mussel each. Each tank contained 500 ml of sea water
(18ppt). The initial concentration of the yeast Saccharomyces
cerevisiae (SAF-Moment, S.I. Lesaffre, 59703
Marcq-France) suspension in tanks was 40 mg dry
weight per liter. The water temperature was 23.4°C.
The optical density was measured spectrophotometrrically
using a SF-26 LOMO spectrophotometer and
cuvettes with an optical path length of 10 mm. Similar
experiments were performed with the oyster Crassostrea
gigas, which was also grown under mariculture
conditions.
The results of our experiments showed that potassium
bichromate is capable of inhibiting the filtration
activity of mollusks (Table 2). This reduces the amount
of food available for the digestive system of the mollusks.
The decrease in the amount of food removed
from water (i.e., the ration decrease) was accompanied
by a visually observed decrease in the rate of formation
of pellets. The amount of pellets in the end of the experiment
in tanks containing potassium bichromate solution
in water (0.05 mg/l) was significantly less than in
control tanks. It was found in our experiments that oysters
(C. gigas) were significantly less sensitive to potassium
bichromate than mussels (M. galloprovincialis).
A similar decrease in the amount of suspended particles
(plankton cells) eliminated from water was
observed in our experiments with other xenobiotics,
including surfactants, synthetic washing mixtures
(SWMs), and liquid washing mixtures (LWMs) (Table 3).
In all cases studied, we found that inhibitors of filtration
activity caused a decrease in the rate of formation
of pellets. Only a few examples of such effects are
shown in Table 3. Inhibition of filtration processes was
also reported by J. Widdows, P. Donkin, D. Page,
A.V. Mitin, and some other researchers [9, 10].
In addition to experimental studies on plankton
elimination from water by marine and freshwater
...
**
New Definitions of the Concepts and Terms Ecosystem
and Biogeocenosis
S. A. Ostroumov
Presented by Academician L.M. Sushchenya November 14, 2001
Received December 6, 2001
Moscow State University, Vorob’evy gory, Moscow,
119899 Russia
0012-4966/02/0304-0141$27.00 © 2002 MAIK “Nauka /Interperiodica”
Doklady Biological Sciences, Vol. 383, 2002, pp. 141–143.
Translated from Doklady Akademii Nauk, Vol. 383, No. 4, 2002, pp. 571–573.
Original Russian Text Copyright © 2002 by Ostroumov.
The terms ecosystem and biogeocenosis were
coined by Tansley in 1935 [1] and by Sukachev in the
1940s [2], respectively. These terms are widely used in
biological research [3–10], and there are several definitions
of the term ecosystem [4–8]. However, a large
body of new biological information has been accumulated
since the time of introduction of these terms.
Therefore, a revision of the currently accepted concepts
of natural objects and interpretation of basic ecological
terms (e.g., ecosystem and biogeocenosis) may be proposed.
It seems reasonable to continue the search for
new variants of definitions of these terms.
The goal of this work was to contribute to this
search by suggesting and substantiating specific definitions
of two basic ecological terms. I certainly realize
that this problem is very complex and its exhaustive
solution is practically unattainable, because it is impossible
to find an ideal definition that would be adequate
to all imaginable situations or satisfy all experts. Nevertheless,
it is worth trying to propose modern variants
of refined definitions capable of taking into account
large volumes of new information concerning aquatic
[6, 11–15] and terrestrial [7, 9, 10, 14] ecosystems.
Sometimes, the terms used in the definition require
additional explanation themselves (e.g., trophic structure,
biocenosis, community, etc.) [3]. For example,
according to a typical definition, ecosystem is a biological
community together with its physical environment
(see p. 679 in [5]). However, this definition by no
means reflects the whole body of experimental findings
and theoretical concepts accumulated in ecology during
the past decades. Given the remarks made above in
this work, the following variant of definition can be
suggested:
Ecosystem is the complex of interconnected living
organisms inhabiting particular area or unit of space,
together with their environment and all their interrelationships
and relationships with the environment. Ecosystem
is characterized by the description of populations
(abundance) of individual species; interspecies
relationships; activity of organisms; physical and
chemical characteristics of environment; flows of matter,
energy, and information; and description of changes
of these parameters with time.
This definition does not contain terms such as
trophic structure, trophic levels, biocenosis, biotope,
community, components, systems, and succession.
Because this definition is applicable to both aquatic and
terrestrial ecosystems, as well as to natural or model
systems of various ranges and degrees of complexity, it
seems to be quite universal. Specific features of this
definition and their substantiation are briefly summarized
in Table 1.
The term biogeocenosis, suggested in the early
1940s by Sukachev [2], has gained wide recognition [7,
8]. This term is widely used in ecological research. The
classical definition given by Sukachev is cited in many
manuals and textbooks. However, a large body of new
ecological information accumulated since the time of
introduction of the term makes it reasonable to consider
new variants of the definition. These definitions should
take into account both recent progress in biological
research and specific features of the current practice of
the use of this term. For example, many researchers
apply this term to aquatic ecosystems. To be applicable
to aquatic ecosystems, the original definition of this
term should be revised. According to the modern taxonomic
system, fungi are excluded from the plant kingdom.
New findings show that the information flow
plays a significant role in the organization of superorganism
structures [9, 14]. Based on a modified definition
of V.N. Sukachev, the following definition of biogeocenosis
can be suggested:
Biogeocenosis is an aggregate of natural components
(atmosphere, rocks, plants, animals, representatives
of microorganisms and fungi, soil and hydrological
conditions, and bottom sediments in the case of
aquatic systems) in a particular area of land or water.
Biogeocenosis is characterized by specific relationships
between components; specific types of matter,
energy, and information flows providing a certain
degree of integrity (unity of components, indivisibility)
...
**
System of Principles for Conservation of the Biogeocenotic
Function and the Biodiversity of Filter-Feeders
S. A. Ostroumov
Presented by Academician V.N. Bol’shakov November 30, 2001
Received December 20, 2001
Moscow State University, Vorob’evy gory, Moscow,
119992 Russia
0012-4966/02/0304-0147$27.00 © 2002 MAIK “Nauka /Interperiodica”
Doklady Biological Sciences, Vol. 383, 2002, pp. 147–150.
Translated from Doklady Akademii Nauk, Vol. 383, No. 5, 2002, pp. 710–714.
Original Russian Text Copyright © 2002 by Ostroumov.
An ecologically substantiated system of protected
terrestrial and water areas is an essential component of
biodiversity conservation [1].
Studies by many authors [2–4] and our own works
[6, 7] showed that filter-feeders play an important role
in elimination of suspended particles from water and its
purification. Therefore, filter-feeders provide habitats
for other species in aquatic ecosystems. This implies
that the problem of conservation of the filtration function
in the population of hydrobionts should be properly
taken into account when developing the system of
conservation of terrestrial and aquatic areas.
The goal of this work was to formulate and substantiate
the suggestion that the system of protected terrestrial
and aquatic areas should be supplemented by sites
intended to conserve the filtration function of filterfeeding
hydrobionts (filter-feeders of zoobenthos, in
particular). An additional goal of this work was to formulate
and substantiate the system of basic principles
and conditions of their protection.
Emphasis should be placed on the following aspects
of this problem: the state of the population of filterfeeders
(bivalve mollusks, in particular); the factors
making it necessary to protect populations of filterfeeders;
and basic requirements for the conditions of
their protection.
The state of the populations of filter-feeders (as
exemplified by bivalve mollusks).
Some species of bivalve mollusks are included in
the Red Data Books of Russian Federation (34 taxa, in
2000) [8] and some other states of the former Soviet
Union. In the North America and Western Europe,
many populations of bivalve mollusks are also endangered
and included in the IUCN Invertebrate Red Data
Book [9].
In many aquatic ecosystems, there is a trend toward
a decrease in the populations and biomass of bivalve
mollusks at polluted sites. This concerns both freshwater
[7] and marine [4] ecosystems.
The state of filter-feeding hydrobionts should be
taken into account in the context of the general state of
aquatic ecosystems. Even in some reserves, the state of
many aquatic ecosystems is far from satisfactory. Using
the methods based on the morphometric characteristics
of aquatic organisms such as the roach (Rutilus rutilus)
and the lake frog (Rana ridibunda), it has been shown
that the state of aquatic ecosystems in the Voronezhskii
State Natural Reserve is unsatisfactory [10]. The state
of aquatic ecosystems was also found to be unsatisfactory
in many places outside state natural reserves: the
town of Voronezh, Lake Kostomukshinskoe (Karelia), a
lake in the Zheleznogorsk raion of the Kursk oblast,
etc. [10].
Factors making it necessary to protect populations
of filter-feeders. There are several factors making
it necessary to protect populations of filter-feeders
(including bivalve mollusks), including:
conservation of the gene pool as a part of biodiversity;
conservation of the gene pool as a resource and a
reserve for aquaculture; and
conservation of water self-purification in natural
water bodies.
Various aspects of conservation of the gene pool were
considered in the preceding works on the general problems
of conservation of biodiversity [11, 12] and more
specific problems of conservation of invertebrates [9].
Let us consider the third factor in more detail. The
role of invertebrates in self-purification of water bodies
was studied by many researchers (for review, see [2–7,
13–15]). The whole volume of water in many large
aquatic ecosystems can be filtrated by bivalve mollusks
within the time interval from 0.7 (South San Francisco
Bay) to 25 days (Narragansett Bay) [5]. Within one
year, marine bivalve mollusks are capable of eliminating,
from water column above 1 m2
of bottom surface,
the amount of carbon ranging from 4.9 to 263 g [5]. The
importance of the general filtration activity of mollusk
populations is illustrated by the data shown in Table 1.
Filter-feeders contribute to regulation of plankton
populations, purification of water, and reduction in the
concentration of suspended particles in water. There-
**
http://5bio5.blogspot.com/2013/02/first-pages-of-innovative-articles.html
These are the first pages of the 4 articles on ecology. They were published in the journal entitled
Doklady Biological Sciences.
This journal is available in many of U.S. university libraries.
This journal publishes English translations of scientific papers that were originally published in Russian in the best scientific journal of Russian Academy of Sciences.
**
**
A New Type of Effect of Potentially Hazardous Substances:
Uncouplers of Pelagial–Benthal Coupling
S. A. Ostroumov
Presented by Academician V.L. Kas’yanov November 7, 2001
Received November 8, 2001
Moscow State University, Vorob’evy gory, Moscow,
119899 Russia
0012-4966/02/0304-0127$27.00 © 2002 MAIK “Nauka /Interperiodica”
Doklady Biological Sciences, Vol. 383, 2002, pp. 127–130.
Translated from Doklady Akademii Nauk, Vol. 383, No. 1, 2002, pp. 138–141.
Original Russian Text Copyright © 2002 by Ostroumov.
Hydrobionts are mediators of “biogenic migration
of atoms in the biosphere” [1]. This migration is partly
implemented in the framework of pelagial–benthal
coupling. Trophic activity of bottom filter feeders
results in consumption of the organic matter of plankton
synthesized in pelagic zones (see, e.g., [2]). Even
the organic matter that is not assimilated by fulter feeders
is involved in pelagial–benthal coupling. Suspended
matter of aquatic ecosystems (including pellets of
invertebrates) is subjected to gravitational sedimentation
[2, 3]. The pellets of invertebrates are formed as a
result of excretion of unassimilated and undigested
food of phytophagous invertebrates. The degree of food
assimilation in different taxa of invertebrates ranges
from 1 to 98% [4, 5]. The mean percentage of food
assimilability averaged over many groups of organisms
is 16.2–89.6% (Table 1). Therefore, the rest of the food
matter (10.4–83.8%) remains unassimilated and settles
to the bottom with pellets. Thus, pellets of invertebrates
are able to transport a fraction of organic matter synthesized
in the pelagic zone by photosynthetic organisms
from this zone to the bottom layers of aquatic ecosystems,
i.e., to the habitat of benthic organisms (the
benthal).
The goal of this work was to determine whether
there is a potential hazard of disturbance of the pelagial–
benthal coupling induced by water pollution. It
should be noted that such a hazard of the pollutioninduced
disturbance of ecosystems has been almost
entirely ignored thus far.
Bivalve mollusks were objects of this study.
Because bivalve mollusks are involved in elimination
and sedimentation of particles suspended in bulk water,
these organisms are components of the pelagial–
benthal coupling [6–11].
The effect of potassium bichromate, a xenobiotic,
on the rate of elimination of suspended particles by the
Black Sea mussel Mytilus galloprovincialis was studied.
Experimental methods were described elsewhere
[10, 11]. Mussels (kindly provided by of A.V. Pirkova
and A.Ya. Stolbov) were grown in water headers in the
outskirts of the city of Sevastopol. The mean body
weights (raw weights with shell) of experimental
(treated with potassium bichromate) and control mollusks
were 6.53 and 6.59 g, respectively. Both control
and experimental tanks contained 13 specimens of
mussel each. Each tank contained 500 ml of sea water
(18ppt). The initial concentration of the yeast Saccharomyces
cerevisiae (SAF-Moment, S.I. Lesaffre, 59703
Marcq-France) suspension in tanks was 40 mg dry
weight per liter. The water temperature was 23.4°C.
The optical density was measured spectrophotometrrically
using a SF-26 LOMO spectrophotometer and
cuvettes with an optical path length of 10 mm. Similar
experiments were performed with the oyster Crassostrea
gigas, which was also grown under mariculture
conditions.
The results of our experiments showed that potassium
bichromate is capable of inhibiting the filtration
activity of mollusks (Table 2). This reduces the amount
of food available for the digestive system of the mollusks.
The decrease in the amount of food removed
from water (i.e., the ration decrease) was accompanied
by a visually observed decrease in the rate of formation
of pellets. The amount of pellets in the end of the experiment
in tanks containing potassium bichromate solution
in water (0.05 mg/l) was significantly less than in
control tanks. It was found in our experiments that oysters
(C. gigas) were significantly less sensitive to potassium
bichromate than mussels (M. galloprovincialis).
A similar decrease in the amount of suspended particles
(plankton cells) eliminated from water was
observed in our experiments with other xenobiotics,
including surfactants, synthetic washing mixtures
(SWMs), and liquid washing mixtures (LWMs) (Table 3).
In all cases studied, we found that inhibitors of filtration
activity caused a decrease in the rate of formation
of pellets. Only a few examples of such effects are
shown in Table 3. Inhibition of filtration processes was
also reported by J. Widdows, P. Donkin, D. Page,
A.V. Mitin, and some other researchers [9, 10].
In addition to experimental studies on plankton
elimination from water by marine and freshwater
...
**
New Definitions of the Concepts and Terms Ecosystem
and Biogeocenosis
S. A. Ostroumov
Presented by Academician L.M. Sushchenya November 14, 2001
Received December 6, 2001
Moscow State University, Vorob’evy gory, Moscow,
119899 Russia
0012-4966/02/0304-0141$27.00 © 2002 MAIK “Nauka /Interperiodica”
Doklady Biological Sciences, Vol. 383, 2002, pp. 141–143.
Translated from Doklady Akademii Nauk, Vol. 383, No. 4, 2002, pp. 571–573.
Original Russian Text Copyright © 2002 by Ostroumov.
The terms ecosystem and biogeocenosis were
coined by Tansley in 1935 [1] and by Sukachev in the
1940s [2], respectively. These terms are widely used in
biological research [3–10], and there are several definitions
of the term ecosystem [4–8]. However, a large
body of new biological information has been accumulated
since the time of introduction of these terms.
Therefore, a revision of the currently accepted concepts
of natural objects and interpretation of basic ecological
terms (e.g., ecosystem and biogeocenosis) may be proposed.
It seems reasonable to continue the search for
new variants of definitions of these terms.
The goal of this work was to contribute to this
search by suggesting and substantiating specific definitions
of two basic ecological terms. I certainly realize
that this problem is very complex and its exhaustive
solution is practically unattainable, because it is impossible
to find an ideal definition that would be adequate
to all imaginable situations or satisfy all experts. Nevertheless,
it is worth trying to propose modern variants
of refined definitions capable of taking into account
large volumes of new information concerning aquatic
[6, 11–15] and terrestrial [7, 9, 10, 14] ecosystems.
Sometimes, the terms used in the definition require
additional explanation themselves (e.g., trophic structure,
biocenosis, community, etc.) [3]. For example,
according to a typical definition, ecosystem is a biological
community together with its physical environment
(see p. 679 in [5]). However, this definition by no
means reflects the whole body of experimental findings
and theoretical concepts accumulated in ecology during
the past decades. Given the remarks made above in
this work, the following variant of definition can be
suggested:
Ecosystem is the complex of interconnected living
organisms inhabiting particular area or unit of space,
together with their environment and all their interrelationships
and relationships with the environment. Ecosystem
is characterized by the description of populations
(abundance) of individual species; interspecies
relationships; activity of organisms; physical and
chemical characteristics of environment; flows of matter,
energy, and information; and description of changes
of these parameters with time.
This definition does not contain terms such as
trophic structure, trophic levels, biocenosis, biotope,
community, components, systems, and succession.
Because this definition is applicable to both aquatic and
terrestrial ecosystems, as well as to natural or model
systems of various ranges and degrees of complexity, it
seems to be quite universal. Specific features of this
definition and their substantiation are briefly summarized
in Table 1.
The term biogeocenosis, suggested in the early
1940s by Sukachev [2], has gained wide recognition [7,
8]. This term is widely used in ecological research. The
classical definition given by Sukachev is cited in many
manuals and textbooks. However, a large body of new
ecological information accumulated since the time of
introduction of the term makes it reasonable to consider
new variants of the definition. These definitions should
take into account both recent progress in biological
research and specific features of the current practice of
the use of this term. For example, many researchers
apply this term to aquatic ecosystems. To be applicable
to aquatic ecosystems, the original definition of this
term should be revised. According to the modern taxonomic
system, fungi are excluded from the plant kingdom.
New findings show that the information flow
plays a significant role in the organization of superorganism
structures [9, 14]. Based on a modified definition
of V.N. Sukachev, the following definition of biogeocenosis
can be suggested:
Biogeocenosis is an aggregate of natural components
(atmosphere, rocks, plants, animals, representatives
of microorganisms and fungi, soil and hydrological
conditions, and bottom sediments in the case of
aquatic systems) in a particular area of land or water.
Biogeocenosis is characterized by specific relationships
between components; specific types of matter,
energy, and information flows providing a certain
degree of integrity (unity of components, indivisibility)
...
**
System of Principles for Conservation of the Biogeocenotic
Function and the Biodiversity of Filter-Feeders
S. A. Ostroumov
Presented by Academician V.N. Bol’shakov November 30, 2001
Received December 20, 2001
Moscow State University, Vorob’evy gory, Moscow,
119992 Russia
0012-4966/02/0304-0147$27.00 © 2002 MAIK “Nauka /Interperiodica”
Doklady Biological Sciences, Vol. 383, 2002, pp. 147–150.
Translated from Doklady Akademii Nauk, Vol. 383, No. 5, 2002, pp. 710–714.
Original Russian Text Copyright © 2002 by Ostroumov.
An ecologically substantiated system of protected
terrestrial and water areas is an essential component of
biodiversity conservation [1].
Studies by many authors [2–4] and our own works
[6, 7] showed that filter-feeders play an important role
in elimination of suspended particles from water and its
purification. Therefore, filter-feeders provide habitats
for other species in aquatic ecosystems. This implies
that the problem of conservation of the filtration function
in the population of hydrobionts should be properly
taken into account when developing the system of
conservation of terrestrial and aquatic areas.
The goal of this work was to formulate and substantiate
the suggestion that the system of protected terrestrial
and aquatic areas should be supplemented by sites
intended to conserve the filtration function of filterfeeding
hydrobionts (filter-feeders of zoobenthos, in
particular). An additional goal of this work was to formulate
and substantiate the system of basic principles
and conditions of their protection.
Emphasis should be placed on the following aspects
of this problem: the state of the population of filterfeeders
(bivalve mollusks, in particular); the factors
making it necessary to protect populations of filterfeeders;
and basic requirements for the conditions of
their protection.
The state of the populations of filter-feeders (as
exemplified by bivalve mollusks).
Some species of bivalve mollusks are included in
the Red Data Books of Russian Federation (34 taxa, in
2000) [8] and some other states of the former Soviet
Union. In the North America and Western Europe,
many populations of bivalve mollusks are also endangered
and included in the IUCN Invertebrate Red Data
Book [9].
In many aquatic ecosystems, there is a trend toward
a decrease in the populations and biomass of bivalve
mollusks at polluted sites. This concerns both freshwater
[7] and marine [4] ecosystems.
The state of filter-feeding hydrobionts should be
taken into account in the context of the general state of
aquatic ecosystems. Even in some reserves, the state of
many aquatic ecosystems is far from satisfactory. Using
the methods based on the morphometric characteristics
of aquatic organisms such as the roach (Rutilus rutilus)
and the lake frog (Rana ridibunda), it has been shown
that the state of aquatic ecosystems in the Voronezhskii
State Natural Reserve is unsatisfactory [10]. The state
of aquatic ecosystems was also found to be unsatisfactory
in many places outside state natural reserves: the
town of Voronezh, Lake Kostomukshinskoe (Karelia), a
lake in the Zheleznogorsk raion of the Kursk oblast,
etc. [10].
Factors making it necessary to protect populations
of filter-feeders. There are several factors making
it necessary to protect populations of filter-feeders
(including bivalve mollusks), including:
conservation of the gene pool as a part of biodiversity;
conservation of the gene pool as a resource and a
reserve for aquaculture; and
conservation of water self-purification in natural
water bodies.
Various aspects of conservation of the gene pool were
considered in the preceding works on the general problems
of conservation of biodiversity [11, 12] and more
specific problems of conservation of invertebrates [9].
Let us consider the third factor in more detail. The
role of invertebrates in self-purification of water bodies
was studied by many researchers (for review, see [2–7,
13–15]). The whole volume of water in many large
aquatic ecosystems can be filtrated by bivalve mollusks
within the time interval from 0.7 (South San Francisco
Bay) to 25 days (Narragansett Bay) [5]. Within one
year, marine bivalve mollusks are capable of eliminating,
from water column above 1 m2
of bottom surface,
the amount of carbon ranging from 4.9 to 263 g [5]. The
importance of the general filtration activity of mollusk
populations is illustrated by the data shown in Table 1.
Filter-feeders contribute to regulation of plankton
populations, purification of water, and reduction in the
concentration of suspended particles in water. There-
**