Harmful algal bloom (HAB) leading to fish kills is no longer a rare occurrence in Malaysian waters, particularly the strategically and economically important Johor Straits. It is a national border between Malaysia and Singapore, and the coastal areas of both sides are dotted with aquaculture, industrial and residential activities.

In our recent paper published in July 2020, in collaboration with the Institute of Ocean and Earth Sciences (IOES), University of Malaya, we discovered the presence a hypoxic-anoxic “dead zone” (low dissolved oxygen) in the inner Johor Straits, spanning an area of more than 10 km square. We also observed seasonal blooms of diatoms Skeletonema, Chaetoceros, Rhizosolenia and Thalassiosira. Diatoms are important for the marine ecosystems. However high nutrient concentration (particularly from human activities) in the water may lead to excessive proliferation of diatoms, inducing the hypoxic-anoxic conditions. Read more here.

This project was funded by the Transdisciplinary Research Grant Scheme (TRGS), Ministry of Education Malaysia.

Reference: Mohd-Din et al. 2020. Prolonged high biomass diatom blooms induced formation of hypoxic-anoxic zones in the inner part of Johor Strait. Environmental Science and Pollution Research. https://doi.org/10.1007/s11356-020-10184-6

Image credit: Terence Ong / CC BY-SA (http://creativecommons.org/licenses/by-sa/3.0/)