Rare Irrawaddy Dolphins Found Along Bangladesh Coast - The Irrawaddy Dolphin is a species of Oceanic dolphin found near sea coasts and in estuaries and rivers in parts of the Bay of Bengal and Southeast Asia. Thousands of rare Irrawaddy dolphins have been found in Bangladeshi waters, a wildlife advocacy group said today, a hopeful sign for a vulnerable species found only in small numbers elsewhere. The Irrawaddy Dolphin is a most intelligent species in the world after humans.