ASSESSING THE IMPORTANCE OF THE BIODIVERSITY OF SÃO TOMÉ AND PRÍNCIPE

Robert Drewes
California Academy of Sciences
California, USA

RDrewes@calacademy.org

The remote Gulf of Guinea Islands of São Tomé and Prìncipe are classic “oceanic” islands; they have never been attached to the African mainland.  This means that the ancestors of organisms native to  these islands had to cross a significant ocean barrier by random chance (dispersal).     Both islands are also geologically ancient.  Prìncipe is at least 31 my old (early Oligocene: six times older than the oldest Hawaiian or Galapagos island), and São Tomé has been emergent for at least 13 my (mid-Miocene).   Isolation over deep time results in evolutionary (genetic) change or speciation in successful island colonizers, leading to endemism; endemics are unique species found nowhere else in the world.
In spite of previous work by Portuguese naturalists, our knowledge of the level of diversity of living species on São Tomé and Prìncipe is far from complete.  For the past 12 years, the California Academy of Sciences has been conducting both marine and terrestrial multidisciplinary biodiversity surveys on both islands, concentrating on lesser known groups of organisms.  These expeditions are beginning to reveal much higher levels of unique species than previously thought.  Thanks in part to modern work by Dr. Martim Melo the island bird fauna is known best, and  the two islands together may contain the highest concentration of unique species (by area) in the world.  Prior to the CAS expeditions, fewer than 15 species of mushrooms were known to occur on São Tomé and Prìncipe.  At least 225 species have now been collected from both islands, and over one-third of them are new to science.  All of the amphibian species are unique to the islands, and recent work suggests that over 70% of the reptiles are unique.  Our on-going biodiversity discoveries to date will be summarized.
With the anticipated advent of oil revenues and other development projects, the islands are undergoing major change which will undoubtedly affect the remaining natural habitats and the organisms that live in them.  In an attempt to prepare for these changes, the California Academy of Sciences is also embarking on a concurrent program of biodiversity education; our goal in this regard is to inform the citizens of the uniqueness of their island habitats.  Knowledge and management of the natural heritage would be prerequisite to generating a successful   “special” ecotourism industry.   The islands are small in area and lack the large charismatic mega-vertebrates that traditionally draw tourists to Africa. Thus they are an unlikely “primary” destination for ecotourism.  However, the incredible number of unique plants and animals, especially the birds and flowers (such as the remarkable Begonias), together with the exquisite natural setting of the islands and the friendliness of their citizens position São Tomé and Prìncipe as an ideal final destination in a package that would begin with mainland forest venues .  Such a niche industry might best be developed in cooperation with neighboring countries where established tourism infrastructures exist.

Keywords: biodiversity; ecotourism, needed infrastructural improvements

Biography note: Robert C . Drewes PhD, Chairman & Curator of Herpetology, California Academy of Sciences, San Francisco California. Since 1969, led 36 research expeditions to 21 different African countries, including five multidisciplinary groups of scientists and graduate students to Sao Tome and Principe and one to Equatorial Guinea. Resulting from this, co-authored three books and over 80 scientific papers.
On the ecotourism side, have been leader/lecturer on 38 popular tours to over 40 countries, world-wide.

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