Rivers and their tributaries are the veins of the planet. They keep alive a variety of species and help sustain fisheries. But human intervention can at times disrupt the fine balance in river ecosystems, raising major challenges. In Bangladesh, dams and the battle for resources have decimated fish stocks and in turn affected the livelihoods of people living on its banks as our reporter Carmen Meyer discovered in her video report. Now, residents are trying to turn the tide. In our background article, author Louise Osborne reports about a similar situation in neighboring Myanmar where new dams are meant to provide the region's growing energy needs. But they are threatening the very survival of local communities.