Phase V – Slippery resource in peril: Ecology of Western Indian Ocean Anguillid eels and their contribution to sustainable fisheries and livelihood along the East Coast of Africa

In this study, specialist scientists endeavoured to elucidate aspects of the biology, ecology, and social value of eels in the WIO region and determine the risk of multiple stressors affecting the life cycle ecology of the WIO Anguillid eels and their contribution to subsistence fisheries in the region. To achieve this regional representation of the WIO, eel distribution included teams in Kenya, Mozambique, and South Africa and has been extremely valuable. The project addressed questions through a plethora of research tasks, including evaluating aspects of the recruitment of eels and how eels use estuaries and lowland rivers to recruit into the African interior. It looked at various biological and ecological aspects of eels as they migrate into rivers. It unpacked where eels occur, how they are doing, what they are doing, and, importantly, how they contribute to the livelihoods of vulnerable African communities. It also considered the multiple stressors that threaten the wellbeing of our eels, and through a regional scale ecological risk assessment, we have considered the probable synergistic effect of multiple anthropogenic stressors on WIO eels. The research has contributed to an improved understanding of the distribution of WIO eels and, importantly, how different eels dominate different areas of the estuaries and rivers of the WIO region. It also discovered and described life-cycle attributes for the WIO region and, unfortunately, demonstrated how WIO Anguillid eels have been negatively affected by numerous anthropogenic stressors, resulting in significant reductions in distributions throughout the region. The research also uncovered illegal trade in live Anguillid eels in South Africa and Mozambique that generates up to US$7500/annum to dedicated fishermen. These same eels harvested by one fisherman could be worth more than US$35000 as a delicacy in Asia. We do not, unfortunately, know how many fishers are involved in this trade but know that a larger secretive inform industry exists that is threatening the sustainability of our WIO eels in Mozambique and South Africa. Similar activities have been uncovered in Kenya. The eels of the whole region also contribute to food security for many vulnerable African communities and have historically contributed to cultural beliefs and values. Unfortunately our research has identified regions where eel migrations have been disrupted and how communities are unable to benefit from the ecosystem services associated with eels. We have also demonstrated how the anguillid eel-associated cultural heritage of communities in southern Africa is being eroded and how beliefs associated with Anguillid eels in the region are drifting into folklore. Our people need to have eels live in the estuaries and rivers where they used to live, before we built dams that affect their migrations.

The risk assessment identified dams and over-harvesting of eels as the major hazards or threats that have resulted in the well-being of WIO eels being in a moderate to high-risk state throughout the region. These results are alarming as all populations throughout the region in all countries are being affected by anthropogenic stressors. Without refuge areas and healthy populations of the four Anguillid eels in any part of the WIO region, the entire WIO populations are threatened. The risk assessment described the risk associated with the maintenance and escapement of eels into the Indian Ocean as the most vulnerable part of the life-cycle history of our WIO eels. While the sustainability of our eels is threatened, and this possibly results in ecological, social, and economic losses to African communities in the region, we are not considering eels in our regional Integrated Water Resource Management. It is not too late we can re-establish connectivity of our rivers, we can conserve our eels, we can sustainably use our eels and enhance the social and economic benefits they offer to all people of the WIO area, but we need to do something soon, because in the last few decades the wellbeing of our eels has deteriorated significantly. Unfortunately the research has not solved all of the questions posed entirely and has increased the list of research questions of the sustainable protection of an use of our WIO eels, we hope that this foundational research which is the first of its kind for the eels of the WIO region as a whole will contribute to improved conservation action and the management of our valuable eels and the water resources of the WIO region they, and we depend on.

The goal of this study was to understand the use and conservation needs of WIO Anguillid eels and contribute to the sustainable management of these fishes in the region. The study aims to determine the risk of multiple stressors affecting the life cycle ecology of the WIO Anguillid eels and their contribution to subsistence fisheries in the region. For the study, we included case studies in Kenya, on the northern extent of the distribution of WIO eels, and Mozambique and South Africa, representing the middle and southern extent of the WIO Anguillid eel distribution.