Lake Naivasha in danger of turning toxic

TIED inextricably to Lake Naivasha’s deterioration is the introduction of foreign species of fish and plant.

Its once clear water has also seen a plethora of damaging ecological changes.

Some were accidental, others manmade. Scientists have also blamed other changes on the booming flower trade around its shores.

The abundance of the South American hyacinth, covering several kilometres of the lake, means less and less light is getting to smaller underwater vegetation. A brown mush is collecting from the dead plants.

Run-offs from rivers above the lake are carrying sand and silt from over-grazed hillsides and top soil disturbed by vegetable farmers which comes down during rainy floods.

These activities move nutrients into Naivasha’s basin, creating mounds of putrid soil and vegetation collections leaving the lake murky. The Lake Naivasha Riparian Association, a collection of local and environmental interests managing the lake, say increased settlements, cattle grazers and vegetable growers are attracted by the economic activity around flower farms.

Increased deforestation over the past 20 years around the lake also means excess top soil is running into the waters.

The fear is, with less light getting to natural plantlife and the build up of nitrates, silt and dead vegetation, an algae is forming which could turn waters poisonous. Samples of a bacteria called a ”blue-green” algae, have been found. If it turns toxic, it could kill animals or even humans once drunk. This would ultimately make the lake a useless, putrid basin, lethal to all who touch it.