Marine protected areas (MPAs) have proliferated in the past decades to protect
biodiversity and sustain fisheries. However, most of the MPA networks have been
designed without taking into account a critical factor: the larval dispersal patterns of
populations within and outside the reserves. The scale and predictability of larval
dispersal, however, remain unknown due to the difficulty of measuring dispersal when
larvae are minute (~ cm) compared to the potential scale of dispersal (~ km).
Nevertheless, genetic approaches can now be used to make estimates of larval dispersal.
The following thesis describes self-recruitment and connectivity patterns of a coral reef
fish species (Centropyge bicolor) in Kimbe Bay, Papua New Guinea. To do this,
microsatellite markers were developed to evaluate fine-scale genetics and recruit
assignment via genetic parentage analysis. In this method, offspring are assigned to
potential parents, so that larval dispersal distances can then be inferred for each
individual larvae. From a total of 255 adults and 426 juveniles collected only 2 parentoffspring
pairs were assigned, representing less than 1% self-recruitment. Previous data
from the same study system showed that both Chaetodon vagagundus and Amphiprion
percula have consistent high self-recuitment rates (~ 60%), despite having contrasting
life history traits. Since C. bicolor and C. vagabundus have similar characteristics (e.g.
reproductive mode, pelagic larval duration), comparable results were expected. On the contrary, the results of this study showed that dispersal patterns cannot be generalized
across species. Hence the importance of studying different species and seascapes to
better understand the patterns of larval dispersal. This, in turn, will be essential to
improve the design and implementation of MPAs as conservation and management tools.
|Date of Award||Dec 2014|
- Biological, Environmental Science and Engineering
|Supervisor||Michael Berumen (Supervisor)|
- Parentage analysis
- Kimbe Bay
- Larval Dispersal