Tests have shown that the phenomenon of mass fish deaths that were experienced in many areas of the Maldives during the end of last year was caused by a type of bacteria, the Marine Research Centre (MRC) has said. According to a statement issued by the MRC, the Centre had sent samples to the Australian, American and Italian laboratories and the results of their tests had revealed that a type of bacteria called Streptococcus was the cause. "This type of bacteria is believed to be connected to similar mass fish deaths that have occurred around the world,' the statement said. "Symptoms of the diseases caused by the bacteria in fish include swollen eyes, change in eye colour, paralysation of the dorsal fin and sudden death.' The statement also said that fish are prone to diseased caused by the bacteria if they swim in contaminated waters for too long and that the disease can be transmitted to other fish in large schools of fish. Due to this the disease can spread very quickly, the statement said. The Marine Research Centre said that as a whole, triggerfish and other similar types of reef fish had been affected by the bacteria in Maldives. "Although the bacteria are known to cause diseases in fish, it isn't rare for humans to be affected too,' the statement said. "However only those who have very weak immune systems are affected usually.'