Welcome to the Marine Mammal and wildlife Research and Community Development Expedition blog where you can keep up to date with all the happenings and information from Kenya

Saturday, November 21, 2009

Kisite Mpunguti MPA is home to East Africa's Second Largest Population of Indo-Pacific Bottlenose Dolphins

The Kisite Mpunguti Marine Protected Area (KMMPA) covers and area of approximately 39 sq. km south of Wasini Island. The wildlife it contains is an important tourist attraction and therefore of economic value to both surrounding communities and the Kenyan government, including GVI's partner, Kenya Wildlife Service, which collects revenue from park fees to finance the management and conservation of protected areas and wildlife in Kenya. Almost every day of the year boat operators bring tourists to the KMMPA to dive and snorkel, but the most significant drawcard these days is the dolphin watching opportunities, with Indo-Pacific bottlenose dolphins (Tursiops aduncus) most frequently encountered, and Indo-Pacific humpback dolphins (Sousa chinensis) also resident year round.

The marine research programme operated by GVI has been developed to satisfy the objectives of KWS in managing wildlife, tourism and other human activities in the area. After 3 full years of research we are happy to report that GVI are able to estimate the absolute abundance of bottlenose dolphins at around 122 individuals. This makes it the second largest known population on the East African coast. The largest is at Kizimkazi in southern Unguja Island, Zanzibar, which holds between 139 and 179 individuals based on research conducted by Stockholm University in collaboration with the University of Dar es Salaam's Institute of Marine Sciences.

Photo-identification and mark-recapture analysis have been employed in both studies, enabling a comparison of population estimates in the region. Photo-identification refers to the identification of individual animals by distinctive features (shape, outline, natural markings and scarring) of the dorsal fins, flanks and flukes. Some scars will remain throughout the lifespan of the animal whilst others will be acquired then fade; the depth and severity of the wound will determine how long it will serve as a unique identification marker for the individual. These distinctive characteristics enable individuals to be recognised when re-sighted and when we plot the rate at which we find new individuals that we haven't identified before, we can estimate the population size; put very (very!) simply, when we stop finding new individuals we know we have 'captured' (on film!) the whole population. Of course research is never that simple so we employ some handy statistics to work out all the complicated parts! Photo-identification also enables us to look at residency rates (whether individuals remain year round or migrate seasonally) and data such as inter-birth intervals, ranging patterns, mortality and social relationships.

Kenya Wildlife Service introduced a code of conduct in 2007 to regulate the interaction of boat operators with the dolphins their tourists are paying to see; unregulated tourism including visitors wanting to swim with wild dolphins has been shown in studies around the world to affect feeding behaviours and even the ability of mothers to care for their calves, causing populations to decline. Despite swimming with dolphins being prohibited in Kenya since 2007, the impact of current tourism activities on the dolphin populations in and around the KMMPA is unknown, in particular it is not known if current levels are sustainable. With the first population estimation for Indo-Pacific bottlenose dolphins provided by GVI and our volunteers over the years, we can now monitor trends in the population level and give KWS the information they need to assess the sustainability and management of tourism in the area.