Why proper management of lakes is critical

Drinking water, agricultural production, energy generation, transport, and habitats for important food species are among key uses of lakes and water reservoirs facing rapid degradation.
Besides acting as ‘sinks’ for sediments and other contaminants, lakes are also a tourist attractions and bear cultural and religious significance to neighbouring communities.
In Tanzania, for instance, about 75 per cent of the population in Mbeya region is dependant on the cheap source of protein offered by Lake Rukwa’s fish. In what was used as a case study in the management of fisheries during an East Africa Great Lakes Observatory meeting held in Nairobi last week, proceeds from fishing within the lake are said to contribute to 20 per cent of Chunya district’s GDP. This is an avenue of financial support for dozens of families in the area.
Freshwater fishery
Such scenarios however may lessen in future as lake resources come under increasing pressure from various challenges including exploitative fish harvesting, erosion, siltation and intrusion of sewerage and drainage wastewaters.
University of Nairobi lecturer Prof Eric Odada says lakes support important ecosystems and as such proper management is essential to boost their resource value and conservation.
While fish are among the most commonly exploited resources from lakes, destructive fishing practices can lead to a decline of these important water resources.
Ismael Kimirei, centre director, Tanzania Fisheries Research Institute, said fish from Lake Rukwa are usually consumed in fresh, smoked or pickled form. While fresh and smoked fish are consumed locally, pickled ones are sold to neighbouring countries such as DRC, Zambia and Malawi in a multi-million shilling industry.
Besides supporting the largest freshwater fishery in the world, harvesting of natural products such as papyrus along Lake Victoria is helping alleviate poverty among communities living in areas surrounding the lake basin. Various uses of the papyrus at different levels of its development such as the umbels (flower heads) for livestock feed, stems which are used as fuel and fish traps, and the inner pith which can be chewed to quench thirst have proved valuable to communities within the Nyando river basin.
Lakes also hold cultural and religious value for communities around the world. An example is the Laguna de Bay in the Philippines, where religious rites such as baptism show the close link between communities living around the lake and the water body. Studies have also shown that the degradation of lakes has a direct consequence on the livelihoods of communities living around them such, as the case in Lakes Chad and Lake Nakuru.
An International Lake Environment Committee (ILEC) report, Managing Lakes and their Basins for Sustainable Use, points to the shrinkage of Lake Chad’s surface from 25,000sqkm to less than 1,500sqkm today.
This has had a direct impact on communities, with less pastureland, clogging of irrigation channels, blockage of river channels by silt, and a growth of weeds, all of which have affected economic activities such as farming, livestock rearing, and fishing. While climatic variations have caused large changes in its depth and salinity, a rapidly growing urban population within Nakuru town has also contributed to Lake Nakuru’s rapid decline.
But there are also lessons that can be borrowed from reclamation of the Lake Tana basin in Ethiopia, where each household in the surrounding areas provides 21 days a year of free labour in reclamation activities.
Says Enyew Adgo from the Bahir Dar University, “This has resulted in 7.2 million people being mobilised in the Amhara region in the past one year alone. The area surrounding the lake basin supports a population of about three million people and has over the years undergone a high rate of degradation driven by population pressure and improper land use.
“Rivers are loaded with silt, and at least 20 grammes of sediment is contained in every litre of water,” says Adgo.
To reclaim the water resource, communities living in the area are actively involved in the rehabilitation of 300 watersheds and converted gullies into productive lands.