Blue Gold by Clive Cussler

An investigation into the sudden deaths of a pod of gray whales leads National Underwater & Marine Agency leader Kurt Austin to the Mexican coast, where someone tries to put him and his mini-sub permanently out of commission. Meanwhile, in South America's lush hills, a specially assigned NUMA team discovers a mysterious tribe, a mythical white goddess, and a murderous cadre of bio-pirates intent on stealing medicinal secrets worth millions.