Kurihokata area spatio-temporal refugia

This outer-lagoon reef-drop is under the jurisdiction of Baraulu village, Kalikoqu District, Roviana Lagoon. The intertidal limestone weathered surfaces of the barrier island becomes a steep reef slope subsiding into the open ocean. The shore is formed of notched and elevated tidal terraces of reef rock. The rocky substrate near the eulittoral zone is covered by sea lichens (e.g., Verrucaria) and algae (e.g., Porolithon onkodes and Halimeda spp.), which develop to variable densities in the intertidal zone. Common invertebrates in this area include Cypraea tigris and C. mauritania, Turbinidae spp., Nerites spp., Tectarius pagodus, and Drupa morum shells, as well as various chitons and sea urchins. Depths ranging between 3 and 200 meters characterize the aquatic section of this habitat. Waters here are clearer than the turbid lagoon waters, affecting the distribution and density of corals such as Pocillopora, Montipora, Acropora, Porites, Goniopora, Pavona, Echinophyllia, Lobophyllia, and Favia species. Two major biological events distinguish this area: the seasonal aggregation of barracudas and the nocturnal burrowing of bumphead parrotfish and Maori wrasses.

Monthly lunar spawning aggregations, including orange-striped emperors during new moons, and yellow-margined sea perches and paddletail snappers during full moons, are common around this area. However, the barracuda season (Sphyraena jello and S. putnamiae) that begins in late August and ends in early January distinguishes the area from nearby reef-drops. Anecdotal evidence and the PI's observations suggest that during these months barracuda assemble to spawn here throughout the lunar cycle, but with greater intensity during the full moon. Spawning aggregations provide fishers with great opportunities for their seasonal exploitation, although this is having a negative effect as suggested by declining CPUE measurements (Aswani 1997a). Fishermen also report that barracuda catches are much lower than they were twenty years ago. More vulnerable to human predation, however, are bumphead parrotfish (Bolbometopon muricatum) and Maori wrasses (Cheilinus undulates). In a single night a pair of skilled divers can haul seven to ten adults weighting over 100 kg. Some communities around the Solomon Islands have banned diving for these species to avoid depleting their reef stocks. In Roviana and Vonavona no such prohibitions have been instated although there is a growing concern, especially in the Munda and Vonavona areas, about the long-term effects of this activity. Munda traditional authorities have been unable to stop divers from decimating these populations. In the Kalikoqu chiefly district the tenure situation, and participation by members of the district, presents a situation that is much more amenable to managing these resources.

Challenges: Baraulu men commonly use this area for bottom-lining barracuda. Closing this resource will thus be difficult, although men may be willing to consider pausing fishing at the peak of spawning periodicity during full-moon weeks from August through December. More scientific data on the demography and life history of the targeted species are needed before determining the exact optimum "no-take" dates. Permanently banning night diving to protect bumphead parrotfish and Maori wrasses is an achievable goal. However, the occasional poaching by marauding Gilbertese may be harder to control. It is likely that "no-take" seasons for some species, and an open status for others, will be implemented. Finally, Baraulu women are considering banning the harvest of invertebrates from this area.