Published: Saturday magazine, Nation newspaper 24 March 2018
Above: Hippos ashore. Copyright Rupi Mangat
It’s late returning to Nairobi from upcountry. We find a campsite to spend the night on the fringes of the freshwater Lake Naivasha, the highest of the Great Rift Valley lakes in Kenya. There’s just enough daylight for a walk around the papyrus-lined shore with the hippos honking, preparing to come ashore to dine for the night.
The papyrus ruffles in the evening breeze. It is an amazing plant. Ancient Egyptians used it to make their scrolls that today show their ancient past. In terms of eco-services, the papyrus is home to wildlife like fish, birds and hippos. The green plant also stabilizes water levels and moderates temperatures around lakes and rivers. Yet today there’s less than 10 per cent around Lake Naivasha.
“There used to be a nearly continuous papyrus fringe all around the lake,” tells Nic Pacini of Naivasha Basin Sustainability Initiative as we stroll along the lake shore. “In some places it was 300 metres wide and had enormous herds of wildlife.”
Sitting around the campfire, Nic updates us on the story of the lake that had the world perplexed as to why it was fresh with no visible outlet to drain it.
“Thirty thousand years ago,” muses Nic, “this was one big lake with Nakuru. Stone-age people lived around Kariandusi, on the edge of the lake.” Dated between 700,000 to 1 million years old, Kariandusi is one of the earliest sites of the hand-axe era.
The water eventually began to flow south of Lake Naivasha through Hell’s Gate Gorge, forming what is now an amazing natural bio-corridor along which buffaloes, giraffes, impala and Thompson’s gazelles migrate to water by the lake shore, monitored by leopard stalking stealthily.
“How are the fish eagles doing?” l ask hearing the call of the white-headed African fish eagle pierce the air.
“Fine,” he replies.
In the recent past there has been concern about the majestic eagle. The concern was the use of agrochemical pesticides. Having accumulated them through the food chain, females affected by high pesticide concentrations tend to lay eggs with a thin shell that break before the chick hatches.
It sets Nic off on another tangent.
Until a century ago there must have been very few water birds around the lake. “There were no fish in the lake, except the endemic black lampeye (Aplocheilichthys antinorii), last seen in 1962, tells Nic.
Few years ago, this tiny riverine fish was listed officially extinct in the International Union for the Conservation of Nature (IUCN) Red data, the global watchdog on tracking species.
Much of this has to do with other fish species introduced for fish farming and sport fishing which drove the endemic fish to extinction and changed the bird dynamic of the lake. Where in the past there were more plant-eating birds around the lake, with the introduction of other species of fish, in flew fish-savouring birds like the African fish eagle, the pelican, the herons, the kingfishers, the cormorants, the spoonbill, the African darter, and many others…
Nic continues with another intriguing fish story.
It’s about the Large-mouthed black bass (locally known as “Naivasha salmon”) that’s eaten with much relish today.
The fish was introduced in the lake from North America in 1929 –for fly-fishing and for the plate as suggested by US President Theodore Roosevelt when he visited the lake at the turn of the 20th century. Today it is infamously listed as one of the world’s top 100 worst alien invasive species by IUCN.
The black bass being a predator needed other fish to prey on.
It set a chain in motion. Fish like the tilapia from Lake Victoria had to be brought in for the black bass to hunt.
It’s a cold night in the tent but deliciously fresh in the morning. A herd of Maasai giraffes make their way along the acacia groves while we keep a watch for the black kite that has been ‘imprinted’. It was found injured as a fledgling and treated at the camp for two years. It recognises its carers and for a bit of fun, it swoops down with talons outstretched on them, astonishing visitors, just to remind them: “this is my home”.
Naivasha – Nairobi is 90 kilometers apart.
Much to do around the lake from boating, birding to biking. Hike Longonot or Hell’s Gate National Park.
To know more about the lake ecology, visit the Naivasha Basin Sustainability Initiative at Kijabe Farm, near Karagta www.naivasha.info