Although recent data suggest that reef fish larvae may have a considerable influence on their dispersal patterns through vertical migration and active swimming behavior, the realized impact of such behavior remains in doubt. For larvae to have a significant impact on their dispersal and survival they must be capable of detecting the direction of currents in the open ocean and/or use a variety of different cues for orientation. Whether reef fish larvae can detect the direction of ocean currents and have any apparent orientation behavior in the open ocean is so far unknown. This study will develop innovative methodology and use an integrated ecological approach to investigate the ability of both newly hatched and late stage reef fish larvae to detect and respond to the direction of current flow in the open ocean, as well as examine their orientation behavior in response to a variety of potential sensory cues on both small (e.g., chemical, visual, and mechanical cues) and large scales (e.g., acoustic, magnetic, celestial, and solar cues) in the open ocean and at various distances from the reef. By investigating the orientation capabilities of a range of reef fish species, this study will provide information vital to understanding the potential for the larvae to influence their dispersal patterns using active behavior.
Broader Impacts - The proposed observational technique could also be applied to a large array of marine organisms that have a pelagic larval stage. The success of the proposed exploratory approach, together with rapid development of remote sensing and camera technologies, could catalyze innovative advances in the field of larval ecology. Over the last decade there has been a trend towards implementing marine protected areas as a safeguard to protecting endangered fisheries species and to enhance stocks through density dependent spill over and increased larval output. An understanding of the connectivity of marine populations through larval dispersal is critical for the optimal design of marine protected area networks as well as for the basic understanding of metapopulation structures. Information obtained from this project has the potential to substantially advance reef management theory worldwide.
