I present research investigating biodiversity and human interaction with the local environment through three perspectives on diverse islands in Fiji's Lau Group. First, I generated long-term data on marine diversity and exploitation through zooarchaeological analyses of fauna from sites spanning the region's prehistoric human occupation. The study areas are representative of regional fauna and local geographic variation in island size and structure. Each island also varies in terms of human occupation and degree of impacts on marine and terrestrial environments. Second, my ethnographic work recorded modern marine exploitation patterns by Lauan communities. Third, marine biological surveys documented living faunas. Together this information is used to explore the marine environment over the three millennia of human occupation. Using data derived from my multipronged study I discuss potential causes of ecological change in this tropical marine setting. My findings include the following: (1) data indicate that relative intensity of human occupation and exploitation determines modern composition and biological diversity of marine communities because human disturbance occurred more extensively on larger islands than on smaller islands in Lau; (2) Lauans appear to have targeted similar suites of marine fauna across their 3,000 years of history on these islands; (3) Lauans have had a selective effect on marine biodiversity because particular species are/were targeted according to local standards of ranking and preference; (4) marine resources existing today have withstood over 3,000 years of human impacts and therefore may have life history traits supporting resilience and making conservation efforts worthwhile.