after all, the island nation l l l l l l l l l l l l l l l . reporter: the seseychelles isa tropical paradise. the archipelago covers around 455 squa kilileterers of land, but morere than 1.3 million sque kilometers of sea. sylvanna: we depend on our marinene resource for everythi, whwhether it is economic activities, for tourism m and fisheries. we don't have anything without that. rereporter: toururism ise country's biggest source of incomeme. many visitors come here for the spectacular naturere. sylvanna: i realalized it was important to conserve the ocean when growing up anand understanding the relalationshp that t the seychelelles peoplee withth the ocean, with the m me osysysuch wewe rely on it. reporter: as a a marine scienti, she's coconcerned about the growing pressurere on the ecosystem. experts go on regular dives to assess the conditions. fishing, environonmental pollution, and t tourism put strain on the seychelles' unique underwater world. the coral reefef c c c c c c e because they're very sensitive to changes in water temperature