An innovative research project is shedding new light on the environmental factors that drive the formation and movement of harmful algal blooms along the northern coast of Oman, with findings that could help better protect desalination plants, fisheries and aquaculture operations. The project, titled “Formation, Characteristics and Advection of Harmful Algal Blooms (HABs) along Northern Omani Coast”, was funded by the Strategic Research Programme of the Research and Innovation Authority in collaboration with the Ministry of Agriculture, Fisheries and Water Resources. It was led by Prof Sergey Dobretsov, Unesco Chair in Marine Biotechnology at the College of Agricultural and Marine Sciences and the Centre of Excellence in Marine Biotechnology at Sultan Qaboos University.
According to Prof Dobretsov, HABs occur frequently in the Sea of Oman and can affect fisheries and aquaculture, disrupt desalination plants, interfere with marine activities and potentially impact the tourism sector. The research therefore sought to better understand the ecology of harmful algal blooms, identify the main environmental factors driving their development, and examine how they are transported and dispersed along the northern coast of Oman. The team combined biological sampling with advanced oceanographic technologies, including sea gliders, to monitor water conditions, circulation patterns and changes in marine ecosystems.
The findings showed that harmful algal bloom development in the Sea of Oman is influenced by a complex combination of environmental and oceanographic processes, including monsoon-driven winds, ocean currents, coastal upwelling, the outflow of water from the Arabian Gulf, internal tides and ocean eddies. Seasonal changes in water column mixing and the thermocline, the layer separating warmer surface water from colder deeper water, were also found to influence nutrient availability and phytoplankton biomass.
The research team observed changes in phytoplankton communities over time, with diatoms becoming dominant from 2018 to 2019, while Noctiluca scintillans was identified as a major harmful algal bloom-forming species in both surface and subsurface waters. The study also examined the role of the oxygen minimum zone, where dissolved oxygen levels are particularly low. The findings indicate that nutrient-rich upwelled waters, together with low oxygen conditions, may contribute to bloom formation, while the inflow of more oxygenated water from the Arabian Gulf can modify the depth and characteristics of the oxygen minimum zone.
The project also examined bacteria associated with harmful algal blooms. Bacillus species were the most abundant bacterial isolates recorded during the sampling period, while analysis of bacterial communities revealed clear differences between bloom and non-bloom phases. The findings suggest a possible relationship between the abundance of Noctiluca scintillans and bacterial community diversity. Potentially pathogenic bacterial strains were also detected, highlighting the need for continued monitoring and further research into interactions between harmful algal blooms and marine microbial communities.
For fisheries and aquaculture, Prof Dobretsov recommended considering historical harmful algal bloom occurrence, water circulation patterns, pollution sources and the influence of oxygen minimum zones when selecting sites. Continuous monitoring of dissolved oxygen, temperature, salinity, chlorophyll and other water quality indicators can provide early warning of bloom development. Aquaculture facilities are also encouraged to establish emergency response measures, including reducing feeding, increasing aeration or oxygen supply, improving water exchange and relocating stock when necessary.
Prof Dobretsov further highlighted the importance of stronger collaboration among research institutions, government agencies and industry to improve harmful algal bloom forecasting, develop more effective treatment technologies and strengthen mitigation strategies.
The project has resulted in four publications in peer-reviewed scientific journals and 10 presentations at international conferences. Three workshops have also been organised on harmful algal blooms, sea gliders and oceanography. The research team was led by Prof Dobretsov as principal investigator, with Dr Gerd Bruss as co-principal investigator, and included Dr Khalid al Hashmi, Dr Aisha al Wahaibi, Dr Ahmed Sana and Dr Talal Etri.
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