Here’s a report from Dino Martins, of the Insect Committee of Nature Kenya (The East Africa Natural History Society).
April 14, 2009

SUMMARY REPORT:
PESTICIDE FISHING IN LAKE VICTORIA

The Insect Committee of the East Africa Natural History Society has been surveying
dragonfly and damselfly diversity of Lake Victoria as part of a summer course (Ecology
of the Great Lakes and the African Savannah) for ~3 years.

As part of the surveys and interaction with fishermen and people involved in the fish trade, we have found that
pesticides are widely used to fish with in certain parts of the lake (especially nearer to
urban areas or towns).

We have gathered data on the prevalence of pesticide fishing and its effect on one
indicator group of insects: dragonflies (Odonata). The prevalence and distribution of
pesticide fished areas was roughly mapped through direct observation of zones of dead
fish that appeared to have been poisoned, and through interviews with fishermen and
other local stakeholders. Diversity and distribution of dragonflies was monitored by
direct observation at different sites. We also looked at dragonfly diversity in areas that
were not pesticide fished (but fished using conventional methods) and in areas that were
protected. The results are very clear: pesticide fished bays have much reduced dragonfly
diversity. On several occasions we found numbers of dead nymphs (aquatic larval
dragonfly life-stage) floating in the water where pesticides had been used, as well as
poisoned non-commercial fish species (mainly cichlids) and other aquatic insects. We
hope to publish the results of the dragonfly survey shortly.

Pesticides are widely available in lake-side towns, such as Mwanza, and sometimes sold
in shops that deal in fishing gear and tackle. Local people were often aware of the
pesticide fishing and were concerned about this. It is apparent that it is a few
unscrupulous fishermen who use this technique and not the majority. Several different
pesticides are used, including ‘Furadan’ which is the cheapest option available in local
shops. For more information, please contact the Insect Committee of Nature Kenya.

The victims of pesticide poisoning are not only fish, invertebrates and lake biodiversity, but include innocent and vulnerable HIV orphans who are who are permitted to pick through and select poisoned fish for their own dinner.

Dino J. Martins
Chairperson, Insect Committee –Nature Kenya – EANHS, Box 4606 Nairobi