Coast News

Indian Ocean Fish Die-off Linked to Plankton Species

Preliminary results of tests done on fish and water samples taken from the Seychelles waters have confirmed the presence of Cochlodinium polykrikoides as the main plankton species responsible for the algal bloom, affecting some areas of the Indian Ocean archipelago. The Republic of Sychelles is a 115-island country 1,500 kilometers east of mainland East Africa.


This has been confirmed by the Seychelles Fishing Authority, SFA, which had already identified the same plankton through tests done locally. Further testing that is being done at the Hydro-Reunion Laboratory, in Reunion island, a French overseas department in the Indian Ocean has now also confirmed that the plankton species, which is toxic in nature, is indeed also toxic for fish species, mainly coral reef fish hence the reason for a large number of fish being found dead at sea or along the beaches.

The abnormal death of a large number of fish being washed up onshore in October 2015 was first observed in various parts of the second most populated island of Praslin and neighboring Cousin nature reserve, the main island of Mahé and other satellite islands.

While it’s been confirmed which is the main species causing the algal bloom and there is certainty that it is toxic for the fish, the effects on human is still unknown, hence the caution for people not to consume freshly caught fish is still in force.

“There is no evidence that the species can have adverse effects on humans…therefore more comprehensive and conclusive tests will have to be done to determine whether and to what extent the species can prove toxic to humans when they consume fish,” said SFA’s Chief Executive Vincent Lucas.

Samples of water and fish are also being sent to France for more comprehensive tests. 

ECO Magazine is a marine science publication committed to bringing scientists and professionals the latest ground-breaking research, industry news, and job opportunities from around the world.


8502 SW Kansas Ave
Stuart, FL 34997


Newsletter Signup

Please type your full name.

Please type your full name.

Invalid email address.

All emails include an unsubscribe link. You may opt-out at any time. Clicking subscribe confirms your acceptance of our privacy policy.