Publication Date:
2021-05-19
Description:
Cyanobacterial mats at hot springs on the shore of the alkaline Lake Bogoria, Kenya, were
investigated regarding species community and cyanobacterial toxin content. The hepatotoxins
microcystin -LR, -RR, -LF and -YR, and the neurotoxin anatoxin-a were present. The mats
were dominated by Phormidium terebriformis, Oscillatoria willei, Spirulina subsalsa and
Synechococcus bigranulatus. The concentration of microcystins in mat samples, ranged
from 221 to 845 mg microcystin-LR equivalents g-1 DW of mat. Anatoxin-a concentrations
ranged from 10 to 18 mg g-1 DW of mat. A contribution of the cyanobacterial toxins from the
hot spring-mats to the mass mortalities of Lesser Flamingos is suggested by: a, the presence of
hot spring cyanobacterial cells and cell fragments, and high concentrations of the
cyanobacterial hepato- and neurotoxins in flamingo stomach contents and faecal pellets; b,
observations of neurological signs of bird poisoning at the lake. Cyanobacterial toxins in
stomach contents, intestine and fecal pellets were 0.196 μg g -1 FW for the microcystins and
4.34 μg g -1 FW for anatoxin-a. Intoxication with cyanobacterial toxins could occur by uptake
of detached cyanobacterial cells from the mats, as the flamingos need to drink fresh- or
brackish water, and to wash their feathers daily, which they do in the vicinity of the hot
springs, where salinity is lower than in the main waterbody of the lake.
Description:
Published
Keywords:
Hot springs
;
Cyanobacteria
;
Phytoplankton
;
Aquatic birds
Repository Name:
AquaDocs
Type:
Report Section
,
Not Known
Format:
pp.67-82
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