Maritime cooperation among the nations of the Indian Ocean Region (IOR) is essential for tackling piracy, terrorism and pollution of oceans, Flag Officer Commanding-in-Chief of the Eastern Naval Command Arun Kumar Singh said on Wednesday. The need for cooperation assumed greater relevance in the context of the 9/11terror attack and the 2004 tsunami. While the 9/11 events held far reaching implications for security, the other focussed on environment and economy, Vice Admiral Singh said, participating in the inauguration of a three-day-seminar at Kovalam, near here, on the changing oceanic landscape in the IOR.