One of them, Atol das Rocas, has already been designated an ecological reserve. Proposals have been forwarded to the Brazilian government suggesting similar procedures for Fernando de Noronha and Trindade Island. Trindade Island has, in fact, recently been spared the threat of construction of a military base. A basic objective in my project is to investigate the source of the prosobranchs that have colonized the islands, and at the same time to test some propositions in insular biogeography. Another aspect to my study is a computer-assisted comparison of prosobranch faunas among the islands, and between each island and the adjacent Brazilian coastal areas.
Special attention is paid to the presence of endemic species on any island or group of islands.
Endemism is a delicate subject to approach, considering that a quarter to a fifth of the species involved in the project are unnamed, and that, despite Rios' pioneer efforts, a large part of the Brazilian coastal molluscan fauna is still unknown. The type of reproductive strategy used by different species may affect faunal composition from island to island. In the development from embryo to adult, some prosobranch species go through a pelagic, or planktonic swimming larval stage. Others undergo direct development, hatching as miniature adults from a brood pouch or egg capsules, and settling down immediately to the life of an adult. The presence of a planktonic larval stage allows a species greater opportunities for dispersal by ocean currents, so that it may colonize distant areas, provided adequate environmental conditions are present, and the arrival of larvae is frequent enough to enable the new population to survive.