This project will address three contemporary issues in marine biology that relate to the connectivity of fish populations across island archipelagos: 1) How did reef fish colonize Hawaii? The Hawaiian archipelago is among the most isolated reef habitats in the world. The primary currents systems of the Pacific flow above or below Hawaii, so it is uncertain how reef fauna dispersed to this area. The two prevailing theories are that they colonized from the West Pacific, or from the South Pacific. Changes in ocean circulation during glacial periods may have enhanced colonization opportunities. Gene genealogies from mtDNA and nuclear DNA will be used to reveal the pathways of colonization, and the age of these events. 2) What are the genetic separations among Indian and Pacific Oceans? During low sea-levels associated with glaciation, the Pacific and Indian Oceans were separated by a land bridge between Asia and Australia. The age and permeability of this barrier will be tested. In particular, it will be determine whether ecological factors (such as habitat specificity) maintain genetic partitions during the long intervals between glacial periods, when the land barrier is submerged. 3) Is the Indo-Pacific core a center of speciation? Is the high diversity in the central Indo-Pacific due to speciation within this region, or accumulation of species that evolve on peripheral islands? These alternatives will be addressed with gene genealogies, to resolve fundamental evolutionary processes. Broader Significance: The conservation status of coral reefs is well documented, and one of the most effective responses is marine protected areas (MPAs). In order to design MPAs, Pacific island nations need to know the level and direction of dispersal among reef ecosystems. The proposed research will define patterns of reef fish (larval) dispersal across the Pacific and Indian Oceans, with special emphasis on Hawaii and the U.S. territories. Indo-Pacific island students will be recruited to collect fin clips for phylogeographic analysis, usually supervised by a local biology professor. The students will participate in this research, view the results, and discuss how findings can influence management of local reef resources. This program will also provide an opportunity to recruit exceptional Pacific Island students to the University of Hawaii. Hawaii Institute of Marine Biology has developed a molecular genetic core facility dedicated to coral reefs and associated fauna. This project will enhance this unique facility, and provide research opportunities to the diverse community at University of Hawaii.
