St. Eustatius Marine Park was established in 1996 and became actively managed in 1997 to conserve and protect the marine environment. It consists of a general use area and two no-take reserves. The purpose of this study is to collect baseline data regarding fish stock populations within the marine park and its reserves in order to evaluate the success or otherwise of the environmental management strategies of the Marine Park. Questionnaires and semi-structured interviews were conducted with eleven fishermen on the island in order to learn more about the St. Eustatius fisheries and to examine changes that have taken place within the last ten years. A visual fish census of the coral reefs was also carried out at sixteen dive sites. The abundance and diversity of fish species were observed, along with length estimations in order to determine the standing stock and population size structure of specific species. The Southern Reserve of the Marine Park was observed as having the most abundant fish population and on average, between twenty and thirty species were observed at each of the dive sites surveyed. Blair’s Reef was identified as being the most diverse with over thirty-five species being observed. The diversity of the fish population in St. Eustatius has been proven to have increased dramatically in the last thirteen years, with the number of species currently present in the waters being on average 4.9 times greater than the number observed in 1992 at the same locations. When asked about the changes in the coral reefs and the fish populations over the past ten years, half of the fishermen said they saw no changes, while the other half said they had seen positive changes, citing more fish and less anchor damage. This clearly indicates that the establishment of the Marine Park nine years ago has been beneficial to the fish population within the local waters.