pollutants in their tissues that compromise their survival
and progeny. Mercury and especially its organic forms
also biomagnify in aquatic food webs (Clark, 2001;
Costa et al., 2012). It is an ecological and analytical challenge to identify and quantitatively describe the
biomagnification process across a given food web
(Cardwell et al., 2013). Ideally, the trophic relations
among the components of the food web should be well
known, and analysis should be made in tissues from
linked trophic positions. The study of the trophic transfer
process along the food web is a useful tool to assess the
biomagnification of trace elements from one trophic link
to another (Cardwell et al., 2013). Also, biomagnification should preferably be confirmed by other analyses such as d
13 C and d
15 N isotopes.
One way to compare biomagnification across food
webs is to plot the linear relationships between log chemical compound and d
15 N and use the regression slope (b)
as a measure of the biomagnification power. The
biomagnification power of a chemical compound is
assessed using regression slope (b) of the simple linear
regression, including all organisms of the food web possible: log[chemical compound] ¼ b*(d
15 N) + a, where
a is the y-intercept. For mercury, the regression slope,
i.e., biomagnification power, values range from 0.10 to
0.28 for tropical, temperate, and arctic marine and lacustrine ecosystems (Costa et al., 2012). This high range
reflects the different composition of the food webs and/or
differences in growth rate of organisms. On the other
hand, the simple linear regression (log[chemical
compound] ¼ b*(d
15 N) + a), including all organisms of
the food web, is a useful tool to compare across habitats
(pelagic, demersal, benthic) or ecological functions of
the trophic web. It also assesses the bioavailability of
a chemical compound to each organism. For example,
the biomagnification power is higher for pelagic and
benthopelagic species than for benthic species. It suggests that the chemical compound is readily available to
the base of the benthic food chain but that trophic transfer
is more efficient in pelagic and benthopelagic food
chains (Costa et al., 2012). As a top consumer, human
populations can often be involved in this environmental
process when ingesting large predatory fish from both
freshwater and marine origins. This constitutes a public
health issue and must be seriously addressed by authorities (Costa et al., 2012).
Bibliography
Cardwell, R. D., DeForest, D. K., Brix, K. V., and Adams, W. J.,
2013. Do Cd, Cu, Ni, Pb, and Zn biomagnify in aquatic ecosystems? Reviews of Environmental Contamination and Toxicology,
226, 101.
Clark, R. B., 2001. Marine Pollution. Oxford: OUP.
Costa, M. F., Landing, W., Kehrig, H. A., Barletta, M., Holmes, C.,
Barrocas, P. R. G., Evers, D., Buck, D., Vasconcellos, A. C.,
Hacon, S., Moreira, J. C., and Malm, O., 2012. Mercury in tropical and subtropical coastal environments. Environmental
Research, 119, 88.
Cross-references
Bioaccumulation
Bioavailability
BIOMONITORS
Vanessa Hatje
Laboratório de Oceanografia Química – CIENAm,
Instituto de Química, Universidade Federal da Bahia –
UFBA, Salvador, BA, Brazil
Synonyms
Sentinel organisms
Definition
Biomonitors are organisms that accumulate contaminants
in their tissues and can be used to yield a relative measure
of the total amount of contaminants in the environment
integrated over a period of time. They respond simultaneously to different stressors, providing quantitative information on the quality of the environment.
Applications and characteristics
To observe the impact of anthropogenic activities on
ecosystems and their development over a long period or
different locations is a large-scale, costly, and timeconsuming task. Monitoring such impacts is a challenge,
once it involves systematic data acquisition in time
and/or space in order to characterize distribution patterns
and trends in all possible environmental compartments in
which contaminants may accumulate (Chapman et al.,
1982).
Biomonitors, by definition, are net accumulators of
trace elements (Rainbow, 2002) and can be seen as
self-contained, self-powered units that can respond to the
presence of contaminants in the environment and are used
for monitoring purposes around the world. Concentrations of contaminants in biomonitors are generally high
enough to be easily measured with minor risk of contamination during sample collection or pretreatment when
comparing to other environmental matrices, such as water
samples. Moreover, the contaminants accumulated in
biomonitors represent the most direct measure of bioavailable metal to an organism, i.e., the fraction of a contaminant that can be taken up from the environment and
therefore with the potential to cause ecotoxicological
effects (Rainbow, 2006; Luoma and Rainbow, 2008).
The first large-scale use of biomonitors was through the
Mussel Watch Program, which developed monitoring
activities using the blue mussel Mytilus edulis to quantify
and assess spatial and temporal trends in coastal contamination of a suit of trace metals (Goldberg, 1986).
Several groups of organisms are currently used as
biomonitors of environmental quality, including crustaceans, fish, corals, macroalgae, and benthic
BIOMONITORS
83
and progeny. Mercury and especially its organic forms
also biomagnify in aquatic food webs (Clark, 2001;
Costa et al., 2012). It is an ecological and analytical challenge to identify and quantitatively describe the
biomagnification process across a given food web
(Cardwell et al., 2013). Ideally, the trophic relations
among the components of the food web should be well
known, and analysis should be made in tissues from
linked trophic positions. The study of the trophic transfer
process along the food web is a useful tool to assess the
biomagnification of trace elements from one trophic link
to another (Cardwell et al., 2013). Also, biomagnification should preferably be confirmed by other analyses such as d
13 C and d
15 N isotopes.
One way to compare biomagnification across food
webs is to plot the linear relationships between log chemical compound and d
15 N and use the regression slope (b)
as a measure of the biomagnification power. The
biomagnification power of a chemical compound is
assessed using regression slope (b) of the simple linear
regression, including all organisms of the food web possible: log[chemical compound] ¼ b*(d
15 N) + a, where
a is the y-intercept. For mercury, the regression slope,
i.e., biomagnification power, values range from 0.10 to
0.28 for tropical, temperate, and arctic marine and lacustrine ecosystems (Costa et al., 2012). This high range
reflects the different composition of the food webs and/or
differences in growth rate of organisms. On the other
hand, the simple linear regression (log[chemical
compound] ¼ b*(d
15 N) + a), including all organisms of
the food web, is a useful tool to compare across habitats
(pelagic, demersal, benthic) or ecological functions of
the trophic web. It also assesses the bioavailability of
a chemical compound to each organism. For example,
the biomagnification power is higher for pelagic and
benthopelagic species than for benthic species. It suggests that the chemical compound is readily available to
the base of the benthic food chain but that trophic transfer
is more efficient in pelagic and benthopelagic food
chains (Costa et al., 2012). As a top consumer, human
populations can often be involved in this environmental
process when ingesting large predatory fish from both
freshwater and marine origins. This constitutes a public
health issue and must be seriously addressed by authorities (Costa et al., 2012).
Bibliography
Cardwell, R. D., DeForest, D. K., Brix, K. V., and Adams, W. J.,
2013. Do Cd, Cu, Ni, Pb, and Zn biomagnify in aquatic ecosystems? Reviews of Environmental Contamination and Toxicology,
226, 101.
Clark, R. B., 2001. Marine Pollution. Oxford: OUP.
Costa, M. F., Landing, W., Kehrig, H. A., Barletta, M., Holmes, C.,
Barrocas, P. R. G., Evers, D., Buck, D., Vasconcellos, A. C.,
Hacon, S., Moreira, J. C., and Malm, O., 2012. Mercury in tropical and subtropical coastal environments. Environmental
Research, 119, 88.
Cross-references
Bioaccumulation
Bioavailability
BIOMONITORS
Vanessa Hatje
Laboratório de Oceanografia Química – CIENAm,
Instituto de Química, Universidade Federal da Bahia –
UFBA, Salvador, BA, Brazil
Synonyms
Sentinel organisms
Definition
Biomonitors are organisms that accumulate contaminants
in their tissues and can be used to yield a relative measure
of the total amount of contaminants in the environment
integrated over a period of time. They respond simultaneously to different stressors, providing quantitative information on the quality of the environment.
Applications and characteristics
To observe the impact of anthropogenic activities on
ecosystems and their development over a long period or
different locations is a large-scale, costly, and timeconsuming task. Monitoring such impacts is a challenge,
once it involves systematic data acquisition in time
and/or space in order to characterize distribution patterns
and trends in all possible environmental compartments in
which contaminants may accumulate (Chapman et al.,
1982).
Biomonitors, by definition, are net accumulators of
trace elements (Rainbow, 2002) and can be seen as
self-contained, self-powered units that can respond to the
presence of contaminants in the environment and are used
for monitoring purposes around the world. Concentrations of contaminants in biomonitors are generally high
enough to be easily measured with minor risk of contamination during sample collection or pretreatment when
comparing to other environmental matrices, such as water
samples. Moreover, the contaminants accumulated in
biomonitors represent the most direct measure of bioavailable metal to an organism, i.e., the fraction of a contaminant that can be taken up from the environment and
therefore with the potential to cause ecotoxicological
effects (Rainbow, 2006; Luoma and Rainbow, 2008).
The first large-scale use of biomonitors was through the
Mussel Watch Program, which developed monitoring
activities using the blue mussel Mytilus edulis to quantify
and assess spatial and temporal trends in coastal contamination of a suit of trace metals (Goldberg, 1986).
Several groups of organisms are currently used as
biomonitors of environmental quality, including crustaceans, fish, corals, macroalgae, and benthic
BIOMONITORS
83