On November 6th a team of socio-economists and ecologists from the ZMT in Bremen will travel to the Spermonde Archipelago in southern Sulawesi. Aim is to conduct preliminary investigations on a gradient of human impacts on the islands and on the fringing reefs, as well as coordinating efforts with local Indonesian partners and hosts. The Archipelago is quite interesting to the team of researchers, as the human influences on the ecosystem are very diverse,
e.g. different modes of fishing, untreated sewage and industrial wastes. In addition, human population densities can be very high on some of the islands. Consequences for the fringing reefs and existing or potential protection measures will be assessed during this first expedition of the archipelago, during which sites for long term investigation shall be identified.
Return to Makassar
For our final survey of the trip we stopped at Pulau Samalona, one of the Spermonde inshore islands. Although it is a famous day trip location for tourists from Makassar, coral reef conditions were worse than around most of the other islands. Due to its inshore location in close vicinity to Makassar city, riverine inputs of nutrients and terrestrial sediment runoff are affecting underwater visibility and macro algae growth, with implications for coral and reef health. Later in the day we reached the main land after a successful 7-day trip in the Spermonde archipelago, during which we visited 19 prospective study sites and got to know the region, reefs and people of Spermonde very closely.
Pulau Kodingareng Lompo
Today, we set sails in the direction of Makassar, stopping at two smaller islands on our way before reaching our night stay Pulau Kodingareng Lompo. It is one of the biggest islands in the archipelago in terms of population and geographical size. As electrical power supply is largely insufficient, parts of the island are facing planned blackouts in a rotating system. The reefs we visited today were in a remarkably good condition, however Acanthaster plancii were sighted in all locations, which represents a significant threat to the well-being of these coral reef ecosystems.
Pulau Karangrang Lompo
Our destination for today, after surveying another 3 islands in close vicinity, was Pulau Karanrang Lompo. Fish abundance around these islands was very low and the reefs were in poor condition. Fishing with explosives obviously still represents a frequently applied fishing technique in this region, which was clearly visible by the substantial underwater destruction caused here. Moreover, our frequent sightings of the corallivorous crown-of-thorns starfish Acanthaster plancii (see picture) indicate, that most of potential new coral recruits may be consumed. This further decreases the chance for significant reef ecosystem recovery.
On this leg of the trip we visited Podangpodang Caddi, an uninhabited island that, according to the people of surrounding islands, seems to be haunted and is rarely visited. As one of the positive side effects, local fishermen also seem to avoid the reefs around the island resulting in an exceptionally high coral cover and fish abundance. As all the islands assessed today lie further offshore, underwater visibility was generally much higher than around most of the inshore islands. During our night stay on Pulau Sarappo, we were kindly invited to join the celebrations of an ongoing traditional island wedding ceremony, which turned out to be an impressive experience.
Pulau Balang Lompo
Today, we visited 4 different inshore islands. Three of them were inhabited and showed very low live coral cover and insignificant fish abundance. The fourth island, Pulau Panambungan, is privately owned and thus in a better condition concerning the above mentioned factors. Visitors need to pay an entrance fee, if they want to visit Panambungan, and fishing seems to be prevented to some extent by local guards. For our night stay, we carried on to Pulau Balang Lompo, the largest island in the archipelago, which seems to be strongly affected by land-based nutrient runoff. Benthic algae cover around the island is exceptionally high and underwater visibility was low compared to all other islands visited so far.
At the end of our second day of the field trip we reached Pulau Badi, where we were welcomed to stay overnight in the house of the head of the island. Our host on Badi runs a very successful community-based mariculture project to breed seahorses for export, the first fully certified and successful operation of its kind in Indonesia. Badi is situated further away from coastal and riverine influences. Due to this fact, underwater visibility improved significantly, as well as live coral coverage and herbivorous fish abundance. Herbivorous fish are essential to the functioning of healthy coral reefs, as they control the growth of benthic macro algae, which represent important coral competitors for space on the reef substratum. From Pulau Badi, we continued our trip on a medium sized Indonesian fishing boat organized by our local host.
Pulau Barrang Lompo (Spermonde Archipelago)
This morning, we left Makassar city with our equipment on a public ferry. Our first destination was Barrang Lompo, one of the main islands in the Spermonde Archipelago. It features a biological station run by UNHAS and extensive aquaculture facilities. Indonesian scientists on Barrang Lompo are trying to restock commercially important ornamental species like sea horses, as well as abalone and snails, to reduce fishing pressure on local reefs in the region. High human population density is a major concern on this island, as power and freshwater supplies are not sufficient during dry season. The reefs around the island are in comparably intact condition, suspended particle load in the water column is high, but fish abundance and diversity are extremely low.
Makassar, South Sulawesi, Indonesia
Yesterday, we reached Makassar after a 2-day trip around half of the globe. The rainy season is about to start, however air temperature and humidity are very high (34 °C, 80 %, seawater temperature: 31 °C). We will spend the next two days in Makassar city to meet with our local partners of the Hassanuddin University in Makassar (UNHAS), who will assist us in the planning and arrangement of our field trip to the Spermonde Archipelago.
On November 6th a team of socio-economists and ecologists will travel to the Spermonde Archipelago in southern Sulawesi (Indonesia). Their aims are to conduct preliminary investigations on a gradient of human impacts on island and fringing reef ecosystems resulting in the identification of prospective research sites, as well as to coordinate efforts with local Indonesian partners and hosts. The archipelago is of significant interest to ZMT’s current research objectives, as local human impacts on island ecosystems in Spermonde are very diverse, e.g. high human population densities, various fishing techniques (largest reef fishery in Indonesia), untreated sewage and industrial wastes runoff.
Dr. Malik Naumann, Hauke Schwieder, WG Coral Reef Ecology