Contribution of hot spring cyanobacteria to the mysterious deaths of Lesser Flamingos at Lake Bogoria, Kenya

Abstract

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 microg microcystin-LR equivalents g(-1) DW of mat. Anatoxin-a concentrations ranged from 10 to 18 microg 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 microg g(-1) fresh weight (FW) for the microcystins and 4.34 microg 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 body of water of the lake.

Possible involvement of microcystins in the unexplained mass mortalities of Lesser Flamingo (Phoeniconaias minor Geoffroy) at Lake Manyara in Tanzania

“…data 2007) in Lake Manyara reported microcystin concentrations of up to 1.1 lg/g dry weight (DW) of phytoplankton. This is supported by several other studies conducted in Kenya which reported high concentrations of microcystins and anatoxins from dead Lesser Flamingo tissue and cyanobacteria samples enough to cause Lesser Flamingo mortality Krienitz et al, 2003;Ballot et al, 2004). Other investigations in Kenyan alkaline saline lakes reported heavy metals (Kairu, 1996;Ndetei & Muhandiki, 2005) and pesticides (WWF-LNCDP, 1994;Nelson et al, 1998) as the cause of Lesser Flamingo mortalities.…”

“…Microcystins analysis in the tissue samples was done at the Norwegian Veterinary Institute laboratory in Norway. The toxin extraction was done as described by Krienitz et al (2003). Three grams of tissue sample were minced in 10 ml of methanol and homogenized using a blender for 5 min under constant cooling, and centrifuged for 5 min at 5000 rpm.…”

Desertifilum fontinale sp. nov. (Oscillatoriales, Cyanobacteria) from a warm spring in East Africa, based on conventional and molecular studies.

“…So far, D. fontinale has only been detected in warm springs, and not in the numerous hot springs found within the vicinity to the locus classicus. Interestingly, the cyanobacterial flora of these hot springs is quite different from that of the warm springs (hinDáK 2001; Krienitz et al 2003;DaDheech et al 2013b). Based on our observations, it is clear that mandatory presence of gas vesicles in the cells for characterization of the genus Desertifilum needs revision.…”

The Influence of Indigenous Food Procurement Techniques on Populations of Cyanobacteria in pre-European Australia: A Potential Small-scale Water Amelioration Tool

“…It has since been identified in the benthic species Aphanizomenon issatschenkoi in New Zealand (Wood et al, 2007). Additionally, until recently anatoxin-a production was not found on any continent that was once a part of Gondwanaland; however, there are now two that are known: one is a benthic species in New Zealand (Wood et al, 2007), and the other is a thermophile from a hot spring in Kenya (Krientz et al, 2003).…”