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The complex relationship between asset wealth, adaptation, and diversification in tropical fisheries

Sarah F.W. Taylor, Shankar Aswani, Narriman Jiddawi, Jack Coupland, Phillip A.S. James, Stephen Kelly, Hellen Kizenga, Michael Roberts, Ekaterina Popova
2021 Ocean and Coastal Management  
Only a limited number of fishers are able to target the large pelagic fish in deeper waters by using small motorised vessels (Jiddawi and Ö hman, 2002; Kizenga, 2020) .  ... 
doi:10.1016/j.ocecoaman.2021.105808 fatcat:56b4en6mj5bg3p2ykhnu62g3mq

Interannual monsoon wind variability as a key driver of East African small pelagic fisheries

Fatma Jebri, Zoe L. Jacobs, Dionysios E. Raitsos, Meric Srokosz, Stuart C. Painter, Stephen Kelly, Michael J. Roberts, Lucy Scott, Sarah F. W. Taylor, Matthew Palmer, Hellen Kizenga, Yohana Shaghude (+2 others)
2020 Scientific Reports  
Small pelagic fisheries provide food security, livelihood support and economic stability for East African coastal communities-a region of least developed countries. Using remotely- sensed and field observations together with modelling, we address the biophysical drivers of this important resource. We show that annual variations of fisheries yield parallel those of chlorophyll-a (an index of phytoplankton biomass). While enhanced phytoplankton biomass during the Northeast monsoon is triggered by
more » ... wind-driven upwelling, during the Southeast monsoon, it is driven by two current induced mechanisms: coastal "dynamic uplift" upwelling; and westward advection of nutrients. This biological response to the Southeast monsoon is greater than that to the Northeast monsoon. For years unaffected by strong El-Niño/La-Niña events, the Southeast monsoon wind strength over the south tropical Indian Ocean is the main driver of year-to-year variability. This has important implications for the predictability of fisheries yield, its response to climate change, policy and resource management.
doi:10.1038/s41598-020-70275-9 pmid:32764628 fatcat:wtfjlsoghrgl3bfz4stath6wom

A Major Ecosystem Shift in Coastal East African Waters During the 1997/98 Super El Niño as Detected Using Remote Sensing Data

Zoe L. Jacobs, Fatma Jebri, Meric Srokosz, Dionysios E. Raitsos, Stuart C. Painter, Francesco Nencioli, Kennedy Osuka, Melita Samoilys, Warwick Sauer, Michael Roberts, Sarah F. W. Taylor, Lucy Scott (+2 others)
2020 Remote Sensing  
Under the impact of natural and anthropogenic climate variability, upwelling systems are known to change their properties leading to associated regime shifts in marine ecosystems. These often impact commercial fisheries and societies dependent on them. In a region where in situ hydrographic and biological marine data are scarce, this study uses a combination of remote sensing and ocean modelling to show how a stable seasonal upwelling off the Kenyan coast shifted into the territorial waters of
more » ... eighboring Tanzania under the influence of the unique 1997/98 El Niño and positive Indian Ocean Dipole event. The formation of an anticyclonic gyre adjacent to the Kenyan/Tanzanian coast led to a reorganization of the surface currents and caused the southward migration of the Somali–Zanzibar confluence zone and is attributed to anomalous wind stress curl over the central Indian Ocean. This caused the lowest observed chlorophyll-a over the North Kenya banks (Kenya), while it reached its historical maximum off Dar Es Salaam (Tanzanian waters). We demonstrate that this situation is specific to the 1997/98 El Niño when compared with other the super El-Niño events of 1972,73, 1982–83 and 2015–16. Despite the lack of available fishery data in the region, the local ecosystem changes that the shift of this upwelling may have caused are discussed based on the literature. The likely negative impacts on local fish stocks in Kenya, affecting fishers' livelihoods and food security, and the temporary increase in pelagic fishery species' productivity in Tanzania are highlighted. Finally, we discuss how satellite observations may assist fisheries management bodies to anticipate low productivity periods, and mitigate their potentially negative economic impacts.
doi:10.3390/rs12193127 fatcat:irrjvolh7jbx7fkq5eubq55a2q