Answer:
harmful algal bloom (HAB)
Explanation:
Harmful algal bloom (HAB) -
It refers to the combination of various organisms , that reduces the level of oxygen in natural water , and which can make the survival of the marine organisms difficult , is referred to as harmful algal bloom (HAB) .
These blooms can live for some days to months , as they die , the microbes decomposes them and consume even more amount of oxygen , making the survival of the marine organisms , near to impossible .
Hence , from the given scenario of the question ,
The correct answer is harmful algal bloom (HAB) .