In early 2023, aUniversity of Oxford expedition ventured beyond the UKfor the first time since the pandemic. The four explorers embarked to Príncipe, part of the two-island state of São Tomé and Príncipe off the coast of equatorial West Africa, to better understand the environmental history, and contemporary human-environment interactions on the island.
The four explorers embarked to Principe
São Tomé & Príncipe (STP) have never been connected to mainland Africa, and their relative isolation have allowed the evolution of endemic species – species that are found nowhere else – much like on the Galapagos islands, which were the basis of Darwin’s Theory of Evolution. Despite their rich and unique biodiversity, São Tomé & Príncipe remain relatively understudied – especially the smaller island of Príncipe.Key knowledge gaps remain about the effect of early human settlement and activity on the islands on its native biodiversity.
STP poses an interesting case study for our research, as the islands are thought to have been uninhabited until relatively recently. Human settlement on the islands likely only started in the late 15th century, when the islands were discovered by the Portuguese. It is understood that human arrival on islands can significantly change ecosystems. Although it is known that a large part of the vegetation and agricultural crops grown extensively on Príncipe were brought from other parts of the world, there is no quantitative information on the island’s vegetation before its human colonisation. We therefore do not know how human-mediated species introductions have changed these earlier ecosystems. By reconstructing ecosystems of the past, we may be able to find out how human colonisation and settlement influenced biodiversity throughout time and provide lessons relevant for contemporary environmental management.
To answer these questions, we collected sediment cores from open water bodies on Príncipe. To collect these, we stand on a raft – so as to not disturb the sediment below us – and carefully lower a sediment corer into the water. Now that our fieldwork period is complete, we will analyse these sediment core samples. Amongst other things, we will be checking for the presence of pollen which can tell us about the plant species present at different points in time. Combined with botanical surveys, these will allow us to understand the state of the environment throughout time by studying changes in vegetation.
We also interviewed local people to understand environmental stewardship practices and empirical environmental knowledge, as well as oral histories.These interviews will form the input for a short documentary which aims to amplify local voices.
a short documentary which aims to amplify local voices.
We were Príncipe for a few weeks – it was a very intense but incredibly rewarding experience. In the first few days, we focused on preparing all the equipment and scouting the lagoas for the surveys. In my case, those first days were filled with designing, prototyping and testing. We wanted to reuse materials discarded by local establishments as much as possible, with the idea of generating minimal waste from our expedition. For example, the raft we used for the sediment coring was built using wooden planks that were left over from hotel furniture.
Once we started conducting the biodiversity surveys and the sediment coring, we all took on different roles. For instance, Denise and I conducted the depth measurement surveys of the lagoas (all that kayaking and rowing experience came in very handy!) before we started doing the sediment coring. For the botanical surveys, Bastiaan and Denise took measurements of selected plants while I collected voucher samples and Sophie photographed these. These samples were then processed and pressed for long-term preservation, and we are now working on finishing this herbarium1. Throughout the expedition, Sophie filmed not only the fieldwork but also the interviews with people of Príncipe.
Now that the fieldwork period is complete, we are analysing the sediment core samples. Amongst others, we will be checking the presence of pollen which can tell us something about the plant species present at different points in time. The botanical surveys will contribute to this analysis, and the voucher samples collected will be identified by a botanist. Once all the data has been analysed, we’ll share our results in scientific publications and in Conferences – we’re presenting our research at the Society of Africanist Archaeologist 2023 this June!
The documentary is currently under production and, once this stage is completed, will be submitted to a few film festivals. After the film has been assessed by festivals, it will be made available to the public online. Through ongoing social media & website posts and the documentary, we hope to raise awareness on the need for environmental conservation and inspire others to develop and implement strategies for a sustainable management of the natural environment.
we hope to raise awareness on the need for environmental conservation
The next season of the Príncipe Past & Present project will focus on further research in selected sites – informed by the results obtained from the first field season – through additional sediment coring. The objective for these samples will be to obtain deeper cores. In terms of the biodiversity surveys, the aim is to build up on the first season and do genetic mapping on site. These results will not only complement the findings from the first season, but also contribute to a larger collaboration with other sites across the Gulf of Guinea.
In addition to the aims of the expedition, the team carried out opportunistic surveys of marine habitats in the north coast of Príncipe as well as explorative archaeological surveys of Ribeira Ize and Mangal Abade. These produced very promising results and provide a first insight into the archaeological material culture of Príncipe. In these sites, large quantities of mixed ceramics were identified and the expedition team mapped surveyed structures. These explorative archaeological surveys are particularly exciting as STP is thought to be the only country in the world where no systematic archaeological research has taken place (Mitchell and Lunn-Rockliffe, 2022), so the findings of these surveys could pave the way for such research!
Biodiversity is under pressure globally from rapid environmental changes. Because of their size and isolation, biodiversity on smaller island nations as São Tomé and Príncipe may be particularly vulnerable to such changes. These include the effects of climate change, such as sea level rise, extreme weather, and reduced crop yields, but also direct human activities resulting in the degradation or conversion of ecosystems. Better knowledge of the unique biodiversity of the islands host will facilitate education and conservation of these unique ecosystems.
São Tomé and Príncipe may be particularly vulnerable to changes in biodiversity
We are hoping that the data collected during the expedition will provide new insights into environmental change and human environment interactions, past and present. We also hope that this field season will form the basis for longer term multi-disciplinary collaboration. Through our documentary we further aim to share the story of Príncipe with the world and inspire others to work towards the sustainable stewardship of their own local environments.