Brian Harvey 
End of the River [PDF ebook] 
Strangling the Rio Sao Francisco

Takes readers from a fisheries patrol boat on the Fraser River to the great Tsukiji fish market in Japan, with stops in Thailand, the Philippines and numerous South American countries. The End of the River is a journey with many companions: some are literary, some imaginary, but most are real characters, human and otherwise, including a six-foot endangered catfish, a Canadian professor with a penchant for Thai bar girls and a chain-smoking Brazilian Brunnhilde. Funny and sad, The End of the River is a brand new take on environmental writing.