The curious case of the suffocating sardines

Muscat: Dozens of dead sardines washed up in a port area in Sidab, officials announced.
On Monday 1st of May, dead sardines emerged from the surface of the water in droves at a port area in Sidab. The port is affiliated to the Royal Oman Police Coast Guard.
The Ministry of Agriculture and Fisheries released a statement clarifying the incident, and reasons for the fish emerging.
"An expert team from the Marine and Fisheries Science Centre inspected the area and collected samples from the fish. They also recorded physical data of the water. After the samples were analysed and the data inspected, the experts found that the large amount of sardines had entered an area in the port basin that was semi closed.
"In addition to that, investigations found that species of Phytoplankton called Prorocentrum Arcuatum was thriving in the area. These reasons led to a sharp decline in water oxygen levels, as the value declined to 1.2 milligram/litre. The sardines had therefore suffocated, and emerged from the water at the port area."