Tropentag, October 5 - 7, 2011 in Bonn "Development on the margin"

Lake Naivasha: Plants, People & Politics

¹University of Leicester, Department of Biology, United Kingdom
²University of Leicester, Department of Geography, United Kingdom

Abstract

Lake Naivasha has been globally famous for over five decades because of its Plants - but not the same species. It was initially renowned as 'one of the top 10 bird-watching sites in the world' - hundreds of bird species and tens of thousands of individuals, all sustained by a species-rich plant community in distinct segments of the 'drawdown zone', from the Acacia woodlands at the top end and the submerged plant beds at 4m depth at the bottom end.
All the native submerged and floating-leaved aquatic plant species, and those two lower zones of the drawdown, were removed from the ecosystem by the first effect of People. The commercial fishery was 'improved' in the early 1970s by the deliberate introduction of the Louisiana crayfish. At the time, nobody realised how destructive of the native plant (and animal) species this alien would be. People, through our global transport mechanisms further changed the Naivasha landscape with alien plant invaders - particularly water hyacinth which arrived in 1989 and filled the empty floating plant niche.
The plant for which Lake Naivasha is now world famous -- the rose -- has been increasingly grown throughout the past 3 decades. Its successful cultivation - for sale to Europe - required irrigation water and labour. Over abstraction of water (including by other demands besides rose cultivation which have grown over the same time), together with a 5-fold increase in the human population, have effectively destroyed the remaining native aquatic plant - papyrus. These dramatic ecological changes have occurred with minimal Political influence - locally, nationally, or internationally - until 2010, despite an adequate legal framework built up by the 1999 Environment Act and the 2002 Water Act. All that changed, because 2009-10 saw the lake level reach the lowest it had reached for 100 years as a consequence of a regional drought whose impact came on top of the over-abstraction. This stimulated major Political initiatives.
The presentation will review the current intiatives in the light of the past events and seek to predict their likely impacts upon and probably benefits for, the lake and its people.

Keywords: Lake Naivasha

Contact Address: David M. Harper, University of Leicester, Department of Biology, Leicester, United Kingdom, e-mail: dmhleicester.ac.uk