Nyandarua Governor Moses Badilisha,
EAWS Executive Director Nancy Ogonje and Wangari Maathai Institute for Peace and Environmental Studies (WMI), University
of Nairobi Director Prof. Thuita Thenya during the launch of the report /HANDOUT
A new comprehensive report reveals that the threatened Lake Ol Bolossat ecosystem supports at least 518 plant species, 278 fungi species, and 162 bird species.
The report dubbed “Unlocking Biodiversity Data to Facilitate Designation of Lake Ol Bolossat as the 7th Ramsar Site in Kenya,” presents fresh evidence to secure stronger environmental protections for the vital wetland in Ol Kalou, Nyandarua county.
Launched on Monday in Ol Kalou, the report is the output of a three-year project implemented from 2023 to 2026 by the East African Wild Life Society (EAWLS) in partnership with the Wangari Maathai Institute for Peace and Environmental Studies (WMI), University of Nairobi, and the Wildlife Research and Training Institute (WRTI). It was funded by the JRS Biodiversity Foundation.
Nyandarua Governor Moses Badilisha, EAWS Executive Director Nancy Ogonje, Nyandarua county commissioner Abdirisack Jaldesa, senior county government officials, scientists were among those who attended the launch.
EAWLS project officer Ann Mukaindo said the assessment of the lake documented an
exceptionally rich diversity of plants, birds, fungi and other wildlife. It provides new evidence to support efforts to secure stronger
protection for the threatened wetland and advance its proposed designation as
Kenya’s seventh Ramsar site.
“The report records 518 plant species, including 148 species newly recorded during the assessment. Two of the plants recorded — Calceolaria tripartita and Lactuca serriola — had not previously been recorded in Kenya, while three regional endemic species were also documented,” Mukaindo said.
The assessment also found remarkable fungal diversity with a total of 278 species documented, compared with only 35 previously recorded.
Those documented include 141 macrofungi and 25 arbuscular mycorrhizal fungi recorded for the first time in the Lake Ol Bolossat ecosystem.
Among the notable findings was Myriostoma cf. coliforme, a rare species listed as Critically Endangered in Britain.
Bird surveys recorded 162 species within the basin. Of these, 24 were species of conservation concern, including three endangered species, two vulnerable species and one endemic species.
Mukaindo said the survey also recorded migratory birds, including 20 Palearctic and two intra-African migrants.
She said modelling indicates that as many as 200 to 375 bird species could potentially be recorded with more extensive survey effort.
The assessment recorded 126 hippopotamuses, underlining the continuing importance of Lake Ol Bolossat as a functioning wetland ecosystem.
Seven mammal species were recorded during the survey which also documented 206 invertebrate species from 16 orders and 17 species of reptiles and amphibians.
“The findings are particularly significant because Lake Ol Bolossat is not only an important biodiversity site but also an ecosystem with a much wider human significance. The assessment describes it as supporting the livelihoods of more than two million people and as an important water source for landscapes extending into Laikipia and Isiolo counties,” Mukaindo said.
The report highlighted challenges facing the ecosystem.
It identifies land conversion, illegal harvesting of vegetation, overgrazing, water abstraction, invasive alien species, pollution, encroachment and climate change among the major threats to biodiversity.
The assessment found evidence of a marked reduction in open water and macrophyte cover, as well as substantial loss of surrounding tussock and forested habitats between 1973 and the 2020s.
A spatial analysis found that approximately 12 per cent of the Lake Ol Bolossat management plan area comprises biodiversity hotspots requiring prioritised conservation action.
Weru ward accounts for 44 per cent of the areas classified as “very hot” for biodiversity conservation, providing a basis for targeting future conservation and restoration interventions.
Agricultural activities are among the pressures affecting the ecosystem.
The socio-economic survey found that 11 per cent of 253 respondents practised irrigation on their farms, with sprinkler or overhead irrigation accounting for 36 per cent of irrigation systems.
The assessment links irrigation to abstraction from rivers, springs and streams and raises concerns about pollution associated with increased use of pesticides and fertilisers.
In addition, diversion of water for irrigation and domestic use has led to over-abstration from streams that feed the lake, reducing inflow.
Ogonje said since 1973, the
lake has lost about 10,137 of tussock grassland, while forest and thicket cover
fell from 1,208 hectares to 485 hectares by 2019.
“Rivers and springs remembered as abundant are increasingly scarce and the lake’s drying in 2023 severely disrupted aquatic life,” Ongonje said.
Governor Badilisha said he will ensure that the threats facing the lake are contained.
The project was designed to address a longstanding shortage of reliable biodiversity data needed to guide conservation, management and policy decisions and to support the proposed designation of Lake Ol Bolossat as a Ramsar site.
The assessment covered seven taxonostragroups — plants, fungi, reptiles and amphibians, mammals, invertebrates, birds, and fish — alongside water quality, land-use and land-cover change, spatial analysis and socio-economic surveys.
All biodiversity data generated through the project have been uploaded to the Global Biodiversity Information Facility, making the information available to researchers, conservation practitioners and decision-makers.
During the launch of the report, a stakeholder workshop, themed “From Evidence to Action: Advancing the Conservation and Sustainable Management of Lake Ol Bolossat Ecosystem,” was also held and brought together about 90 stakeholders from national and county governments, conservation organisations, community groups, research and academic institutions, development partners and the private sector.
The workshop formally launched and disseminate the Biodiversity and Socio-economic Assessment Report and present the findings of a Management Effectiveness Assessment undertaken as part of the wider project.
Stakeholders also consider a policy brief containing recommendations for the County Government of Nyandarua and other relevant institutions.
The event will provide a platform for stakeholders to consider what the new evidence means for the future of Lake Ol Bolossat and to identify priority actions for conservation, restoration, improved management and long-term sustainability.
The project has also produced information and education materials, including biodiversity posters and a Field Guide to the Birds of Lake Ol Bolossat while supporting biodiversity monitoring and awareness among local communities and school-going children.
The assessment recommends that Lake Ol Bolossat be designated a Ramsar site, noting that the ecosystem meets Ramsar Criteria 1, 2, 3 and 4.
This is based on its distinctive wetland characteristics; its support for vulnerable, endangered and critically endangered species and threatened ecological communities; its importance for maintaining biological diversity; and its support for species at critical stages of their life cycles because of its distinctive wetland characteristics, its support for vulnerable, endangered and critically endangered species and threatened ecological communities, support of species in their critical life cycle stages.
The launch therefore marks not simply the publication of a scientific report, but an opportunity to translate a substantially expanded evidence base into policy and practical action to secure the future of one of Kenya’s important and increasingly threatened wetland ecosystems.
