A new study by Flinders University has found why Southeast Asian seas produce more fish than the world’s largest coastal upwelling regions combined.
For the first time, they have described how transient short-lived wind events trigger the formation of significant phytoplankton blooms near tropical reef islands, such as the disputed Spratly Islands in the South Island Sea and many other islands in the Pacific Ocean.
“The key here is that the tropical Pacific contains thousands of such islands, which implies that tropical wind events can create a large network of marine ecosystems existing year-round and spanning thousands of kilometers, possibly forming one of the largest upwelling biomes on Earth,” says Associate Professor Jochen Kaempf, lead author of the new article published in the Journal of Oceanography.
“We believe that this (Asia-Pacific) upwelling biome provides critical feeding habitats for migratory marine species such as sea turtles, tuna and whales. For instance, pygmy blue whales migrate from their feeding habitat in upwelling regions of southern Australia to their breeding grounds in Indonesian waters, where they seem to gather near Christmas Island and volcanic arc islands of the Banda Sea. Our findings suggest that this behavior is primarily feeding-related.”
Associate Professor Kaempf says that the discovery paves the way for closer examination of phytoplankton bloom mechanisms in tropical oceans, particularly in the light of sea-level rise, enhanced wave erosion, and changes in tropical rainfall and winds due to climate change.