Abstract:
Microcystins are part of algal toxins produced intracellularly within algal cells, being
in the family of hepatotoxic cyclic peptides from various species of blue-green algae.
Blue-green algae are widely abundant in many equatorial eutrophic lakes, including
Lake Victoria, with microcystin mainly from cyanobacterial blooms released into
the water column, with different effects along the aquatic ecosystem trophic levels.
Depending on the length of exposure and exposure route, microcystin effects on fish
can include embryonic hatching perturbations, reduced survival and growth rates,
changes in behavior, osmoregulation, increased liver activities and heart rates, as well
as histopathological effects. While bioaccumulation is confirmed among fish, biomag-
nification along food webs is debatable. Lake Victoria the second largest freshwater
lake in the world, and the source of livelihoods to millions reported near the gulf and
shore MCs of 190 ± 51 to 543 ± 26 ng MC/g DW, respectively. Little is known, how-
ever, on the effects of microcystin on the Lake Victoria fishery and, ultimately, on the
human population against the WHO recommended human microcystin intake levels
of 0.04 μg/kg, thereby being the basis for this review.