Researchers in Botswana's Okavango Delta like to keep a safe distance from cranky hippos. Hippos usually return the favor, at least that is what I thought until, during a recent CI-supported AquaRAP survey, one roughly nudged our mokoro (dugout canoe) from behind. Only the skill of our boatman got us out of there alive!
We had come to the Okavango, a vast oasis on the edge of the Kalahari Desert, to collect baseline biological data. Gathering such information is a critical first step in a long-term monitoring project CI is launching to help improve conservation management in the region. The Delta, a high-biodiversity wilderness site and critical source of food and water for communities
and wildlife, is threatened by poorly planned tourism, pollution, fisheries conflicts and, most urgent, a proposed dam upstream in Namibia. If built, the dam would likely disrupt the dynamic seasonal flooding of the Delta, drastically altering its ecology.
Our AquaRAP team, composed of 15 international, regional and local scientists, evaluated four aquatic sites, closely examining the Okavango's vast array of aquatic organisms and measuring water quality. I paid close attention to macroinvertebrates, my specialty. These tiny creatures, which include snails and shrimps, constitute the lower level of the food chain and play a key role in sustaining the entire Delta ecosystem.
In addition to gathering valuable new data about the Delta, the survey provided a snapshot of the importance of the Okavango's dynamic hydrological system. The seasonal floods combine with occasional rainfall to create high habitat diversity, which results in larger numbers of aquatic plant species
. The annual cycle of establishment and die-off of plant species, in relation to the flood pattern, is considered to be the main driver for species diversity in the Okavango.
We believe such information, combined with the extensive knowledge that can only be gained from long-term monitoring, will provide critical scientific ammunition necessary to block potentially destructive projects, such as the building of the Namibia dam. It will also ensure a future for all who depend on the Delta, including hippos having a bad day.