Application of satellite multi-sensor techniques to detect upwellings and potential fishing grounds in Wakatobi Marine National Park, Southeast Sulawesi, Indonesia

Abstract

Information about Yellowfin Tuna fishing grounds is needed to develop the capture fisheries sector, which could be obtained through satellite multi-sensor mapping techniques. Fishermen often have difficulty determining where the fish are and when they can be caught in abundance. Knowing this information would sufficiently reduce operating costs. Mapping the fishing ground of Yellowfin Tuna would also avoid overfishing due to the concentration of fishing boats in one particular location, thus allowing the operation to be more effective and efficient. The long-term aim of this research is to improve the welfare of fishermen in the Wakatobi district, Southeast Sulawesi, while the short-term goal is to map the fishing ground of Yellowfin Tuna (Thunnus albacares) with the application of multi-sensor satellite technology to detect upwellings. The benefits of this research are cost savings for the fishermen and providing a reference for the arrangement of management strategies of Yellowfin Tuna (Thunnus albacares) for sustainablity and continuity. This study indicated that the average sea surface temperature in the west was 29.79°C, in the west-east an average of 29.70°C, in the east an average of 27.40°C and the east-west an average of 29.13°C. Chlorophyll-a in both the west and the west-east averaged 0.15 mg m−3, in the east 0.27 mg m−3 and in the east-west 0.21 mg m−3. High temperatues started in December and continued until February in the Wakatobi region, which moved from west to east. Low temperature moved from east to west from June until August. Fronts occured arround Kaledupa and Koromaha reef in December, January and February, as well as in March, April and May around Kaledupa reef and Runduma Island. In June, July, August, September, October and November fronts were observed around Kapota reef, Kaledupa reef, Koromaha reef and Koka reef. Upwelling occured in Kapota reef, Kaledupa reef and Koka reef in June, and in July and August around Runduma Island, Kapota reef, and Kaledupa reef. Furthermore, upwelling in Kapota reef, Wangi-wangi Island, and Kaledupa reef was observed in September.

Bioeroding sponge assemblages: the importance of substrate availability and sediment

“…Similar results have been found elsewhere in Indonesia; Holmes et al (2000) found that bioeroding sponge occupation of massive corals correlated with chl- a concentration on polluted Javan reefs but not in Ambon where chl- a was less concentrated and more consistent across sites. The majority of our chl- a measurements deployments took place during the dry season (June–August) when chl- a concentration is at its highest (Tadjuddah et al , 2012). However, the broad scale seasonal upwellings that are responsible for this peak in chl- a (Wyrtki, 1961), might also mask inter-site variation in chl- a concentration from local sources.…”

Developing a model for the integration of Bajau traditional ecological knowledge in the management of locally managed marine area: a case study of Wakatobi regency, Indonesia

“…Their knowledge about fishing grounds and migratory lanes of Tuna, especially Yellowfin Tuna (Thunnus albacares), is documented as the upwelling areas. Possibly, this TEK might be integrated with satellite mapping to increase the economic income of the Bajau in Wakatobi (Tadjuddah et al, 2012).…”