gerard ryan is a dolphin researcher. he uses special camera equipment to track the dolphin population in the area. he fears that if the dam in laos is built, more will follow. there are currently plans for ten more dams along the river in cambodia. >> there are two dams planned within dolphin habitat , one at sanbur and one at stuntrek, and another one just upstream at dontahongins in southern laos. and i think any of those dams could have a very significant impact on this population and potentially wipe it out even. >> river traffic is heavy close to cambodia's capital city, phnom penh. the mekong is the lifeblood of the country. people here get 80% of their protein from fish. that's why cambodians are so concerned about the effect the dam will have on the mekong ecosystem. chum hang tong is the head of a state-owned fishing operation in phnom penh. he's been campaigning for construction to be pushed back by ten years to monitor the effects on fish. but that appeal was rejected. the fish will no longer be able to migrat