Commonly caught fish species as potential indicators of pollution along lake nyasa (lake Malawi), Tanzania
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Date
2024
Journal Title
Journal ISSN
Volume Title
Publisher
Royal Society of Chemistry
Abstract
The chapter presented the potential use of frequently caught fish species
from Lake Nyasa as bioindicators of pollution that is likely to be a result of
human activities. The effects of pollution can be magnified if proper and
periodic assessments of risks associated with the pollution are not properly
done. The sampling and analyses of pollutants accumulated in the sediments
is always difficult. However, pollution induces stresses that can be detected
through the molecular analysis of the fish. Thus, parameters such as genetic
diversity, haplotype diversity (h), nucleotide diversity (π), observed heterozy-
gosity (Ho) and unbiased expected heterozygosity can be used as potential
indicators of the effects of pollution in aquatic systems.
It is also possible for a pollutant contained in the aquatic systems to accu-
mulate in the body tissues of the fish. The concentration of persistent and
non-biodegradable heavy metals in fish increases with eating behaviour, age
or rate of exposure. Thus, the concentration of heavy metals may vary from
one fish species to another depending on the factors. The heavy metals accu-
mulated in the body of the fish can be used to estimate potential risks that
can be caused by pollution to human health.
The toxicity of a pollutant highly depends on the chemical form in which
it is present in the aqueous environment. For example, organic mercury is
more toxic compared to inorganic mercury due to its ability to penetrate
through various blood barriers and cause neurological damage. The chem-
ical characteristics of a toxicant vary from one another. Thus, to estimate
potential risks associated with a certain pollutant, the analysis of a specific
chemical species is required. The use of fish as a potential bioindicator can
be significantly more relevant, if these aspects are borne in mind during the
chemical speciation analysis.
Description
Book chapter
Keywords
Caught Fish Species, Water Pollution, Lake Nyasa, Coal Mining, Lake Malawi, Tanzania