
My PhD Journey

KENNEDY OSUKA
Senior Scientist

Exploring the frontiers of marine research
My thesis studied the connections between shallow reefs (0-30 m) and deeper reef habitats (30-150 m) in the Indian Ocean. The objective was to increase an understanding of existing depth refuge pathways and their vulnerability to climate change. To achieve this, I collated information on marine protected areas (MPAs) in the Indian Ocean, and I applied a variety of survey methods (marine robots to baited cameras to visual censuses) in the shallow and deeper habitats of the Pemba Channel in Tanzania.
My research explored four main questions:
i) How do variations in levels of protection impact the structure of fish communities and the productivity of reef systems?
ii) What factors shape the presence of seafloor substrates, benthic variables, and fish communities from shallow to mesophotic depths in the Pemba Channel and are the patterns similar to those reported in other regions?
iii) How does depth and habitat type influence the fish species targeted by fisheries in the Pemba Island?
iv) Which survey method is most accurate in estimating the abundance of large, coral reef-associated predatory fish?
A key finding from the study was the importance of protecting deeper waters as refuges for fish and benthic communities. This can be achieved through designation of marine protected areas (MPAs). By identifying areas that act as refuges from the effects of climate and fishing, we can better protect these coral reefs and the species that depend on them. My research overall supported the importance of protecting deeper waters as refuges for fish and benthic communities.
But wait, there is more! I also worked on several other studies in the field of coral reef ecology, and marine conservation and management. This included work on marine survey technology; coral reef fish ecology in the Red Sea and Western Indian; the management of artisanal fisheries in Kenya and Mozambique; the influence of climate change on East Africa’s coastal fisheries; the management and conservation of reef sharks; socio-ecological systems of Mozambique’s fisheries; the implications of COVID-19 on marine protected areas; and policy pathways for rebuilding coral reefs.
My experience and research in the field of coral reef ecology and conservation proved fulfilling overall, and I am excited to see the impact it will have on the preservation of these delicate ecosystems in the future.
I must thank my thesis supervisors, Dr Bryce Stewart and Dr Colin McClean, for their unwavering support throughout my research. Without their guidance and encouragement, I could not have achieved this milestone. I am also grateful to my Thesis Advisory Panel members, Dr Melita Samoilys (CORDIO East Africa), Dr Philip Platts (University of York) and Prof Callum Roberts (University of Exeter). Their feedback throughout was more than I could have asked for. I will also extend my sincerest gratitude to Dr Dean Waters (University of York), the entire staff of CORDIO East Africa and the Department of Environment and Geography at the University of York. This journey in many ways was a team effort.
As I sign off, allow me to acknowledge the generosity of those who made this research possible: the Sustainable Oceans, Livelihoods, and food Security Through Increased Capacity in Ecosystem research in the Western Indian Ocean (SOLSTICE-WIO) Programme), the Norwegian agency for development cooperation (Norad), Perivoli Philanthropy, and Mr. Dev Joory.
So, as I bid farewell to my PhD days, I want to thank everyone who made this adventure possible. I’m delighted to have earned my PhD at the University of York, and I’m looking forward to discovering even more about Fish Ecology and Fisheries Management in the future!
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