Research project: Larval-fish ecology – on larval-fish orientation
- Start date:
- Hermon Slade Foundation
One of the most important questions in marine biology today is: what are the spatial scales over which animal populations are connected by larval dispersal? Answering this question is essential for theoretical understanding of population dynamics in marine systems, effective management of fisheries, conservation of marine biodiversity (including design and operation of Marine Protected Areas), and predicting the effects of climate change on marine systems.
The vast majority of bottom-associated (demersal), bony fishes have a pelagic larval stage subject to dispersal in open water over a pelagic larval duration of days to weeks. Thus, it is the pelagic larval stage, not the demersal adult stage, that sets the spatial scale for population connectivity and for the geographic size of fish populations. As a result, unlike terrestrial vertebrate populations, marine fish populations are generally considered open, with young potentially derived from distant sources and with management scaled accordingly.
The overall objective is to investigate the orientation abilities of fish larvae. Specific aspects include:
- Direct comparison of the methods of Leis (diver observation) and Paris (OWNFOR) for the study of larval-fish orientation with the same species and at Lizard Island. This will enable us to assess any bias introduced by the presence of divers.
- Study of the influence of schooling by the larvae on the precision of their orientation.
- Study of the influence of sunlight on orientation, using OWNFOR. Using filters, we can control the quality and quantity of the light reaching the larva, and thus determine if larvae use a solar compass for orientation.
- Study of the differences in orientation of fish larvae on different sides of Lizard Island