Assessing the potential impact of a mass coral bleaching event on Red Sea fisheries

  • Claire Shellem

Student thesis: Master's Thesis

Abstract

Worldwide, coral reefs are recognized as highly valuable ecosystems offering numerous environmental and economic services. In Saudi Arabia, the primary ecosystem service derived from coral reefs is the support of reef-based fisheries, accounting for ~75% of total fisheries landing in the kingdom. Saudi Arabian reefs experienced high fishing pressure for decades due to the growing population and associated fishing pressure. Despite the importance of the provisioning service there are limited ecosystem services valuations for this region. In the wake of a 2015 mass bleaching event, we quantified the effect of habitat degradation on the potential fisheries revenue in the central southern Red Sea. We conducted in situ reef fish surveys in 2014 and 2015 before the bleaching event and in 2019, nearly four years after the bleaching event. Using species-specific prices collected from local fish markets, we calculated values per hectare from multiple reefs in this region, to assess how the reef-based fishery was impacted by the bleaching event. A loss in live hard and soft coral cover was recorded after the bleaching event with associated shifts in the dominance of commercially important fish species. Notably, prior to bleaching, a larger proportion of the high value carnivorous species (70% carnivores, 25% herbivores) dominated the fish assemblage whereas post-bleaching reefs had a higher dominance of lower-valued herbivorous species (25% carnivores, 50% herbivores). While the total revenue was not significantly different before (7,913 USD/hectare) to after the bleaching event (6,814 USD/hectare), the loss of high value species observed suggests that if reefs continue to degrade there are potential negative flow-on effects impacting fisheries provisioning with time. Overall, an increasing percentage of live hard coral cover was positively correlated with fisheries revenue per reef, further providing evidence for the potential loss of revenue in degraded reef ecosystems in the region.
Date of AwardApr 2020
Original languageEnglish (US)
Awarding Institution
  • Biological, Environmental Science and Engineering
SupervisorMichael Berumen (Supervisor)

Keywords

  • Provisioning
  • Artisanal fishery
  • Coral Reef
  • Reef Degradation
  • Ecosystem Services
  • Saudi Arabia

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