Monitoring Domestic Livestock
In desert environments it is not only Desert Locust that eat the vegetation - the desert can be home to grazing and browsing livestock which form the wealth and livelihoods of Nomadic herdsmen throughout vast areas of the Sahara.
The pesticides used in control operations against Desert Locust may have an impact on the health and well-being of these livestock , but little research had been done on this subject.
The first part of this work involved a review of camels in Mauritania, including numbers, geographical movement and economic importance.
The second stage was to examine, by visiting Nomads, whether they considered that pesticide use posed a hazard to the health of their animals. Amongst the Nomads questioned, none mentioned Desert Locust control operations as having an impact on their animals. The major problems mentioned were lack of grazing, infections and reproductive problems - especially abortion. Abortion in camels has occasionally been cited as a side effect of pesticide use, although there is no scientific evidence to support this. Among the Nomads questioned by the project abortion was often attributed to camels eating the frass of Desert Locust, or alternatively, to camels ingesting (an unidentified) lepidopteran larvae while browsing on Acacia. In some cases Nomads welcomed locust control operations as they believed that a side effect was the reduction in population of these larvae - and thus reduced risk of abortion.
The third stage of this work has been to use the same technique as used on humans for monitoring the levels of acetylcholinesterase (AChE) in camels exposed to pesticide through grazing on vegetation treated as a result of locust control operations (photos). This has been done in close cooperation with Ceres/Locustox. Initially, it was necessary to assess the variability of AChE levels in the population. Over 200 camels were sampled in this phase. The data provided the background to which exposed animals could be compared. (Under operational conditions it would be highly unlikely that a specific individual animal could be sampled before and after treatment). The data together with data from other species, will be available on the Ceres/Locustox website.
Following an operational treatment with an organophosphate insecticide, 22 camels that had entered the treated area after spraying were sampled for AChE levels 4 days after entering the area. No reduction in AChE levels of these animals compared to animals outside the treated area was detected. It must be stressed that the data was from a single operation and must be repeated before reliable conclusions can be drawn. However, it has become apparent that the importance of camels to Nomads is such that they are reluctant to allow them to be handled unless absolutely necessary, which has meant that to date it has not been possible to continue with this work.
The project together with Ceres/Locustox have successfully developed a technique of assessing exposure of camels to pesticides during Desert Locust control operations.
(Available in French only)
General Background (PDF 28 Kb)
Camel Health Study (PDF 18 Kb)