Saumu Rumba, Cosmas Munga, Jean Huge, Farid Dahdouh-Guebas

Abstract

Mangrove ecosystems are important worldwide in maintaining coastal and marine biodiversity, mitigating climate impacts and providing ecosystem services. However, mangrove forests have declined due to natural and anthropogenic stressors. Recording changes over a large timescale requires considerable periodic efforts, which may not be possible for most mangrove ecosystems in the world. Gazi Bay in south coast of Kenya provides a relevant example to study the dynamics in mangrove usage. This study therefore, assessed the variability of mangrove utilization in Gazi Bay within the last three decades (2000s, 2010s and 2020s) using semi-structured interviews. The interviews addressed ethnobiological utilization of mangroves, fishery-related activities and the perception of the local community towards changes in the forest. A total of 82 interviews in 2003, 82 interviews in 2014 and another set of 98 in 2021 were accomplished to cover three decades. Results show that usage of mangrove species has changed over time. The usage of Avicennia marina and Xylocarpus granatum for fuel wood increased in 2021. Usage of Rhizophoramucronatahas been consistent. The usage of mangroves for medicinal and chemical properties as well as fodder for animals and food for humans has decreased over indicative of erosion of Traditional Ecological Knowledge (TEK). Overall, there is a shift in mangrove utilization patterns over the three decades. A decrease in fish catch was also reported over the three decades attributed to illegal fishing practises and environmental degradation over time. The local community noticed changes in the mangrove areas. Natural regeneration, regular planting, a ban on cutting and conservation awareness were perceived as being the causes of increase in mangrove area. More research on local use of mangroves should continue to constantly update the policies for sustainable mangrove management.

Keywords: Mangroves, Ethnobiology, Utilization, Gazi Bay, – Kenya