Fish Fauna

Abstract

The Semporna reef complex is located within the Coral Triangle region, where the highest numbers of marine species are found. Semporna has the largest concentration of reefs within Malaysia. Semporna is unusual because of its rich mix of reef types, representing 5 major geomorphological reef types, which include a proto-atoll, an offshore seamount, fringing reefs, patch reefs, and a barrier reef formation. Such areas usually have high levels of biodiversity because of the mix of habitat types and ecosystems. There is one existing marine protected area in the district which covers 350 km2 out of the approximately 7,680 km2 of Semporna PCA. The Tun Sakaran Marine Park contains 8 islands and is the first marine protected area in Malaysia to include local communities within its boundaries. Sipadan Island’s waters are proposed as a park and the intention to gazette was published in mid-2009. Previous reef status surveys from WWF-Malaysia in year 2009 found that there are no reefs with more than 75% live coral cover (those surveys did not include Sipadan or the Tun Sakaran Marine Park). Marine biologists from Malaysia, the Netherlands and the USA assessed the marine biodiversity and coral reef health during the expedition onboard MV Celebes Explorer from 29 November to 18 December 2010. The expedition was organized by WWF-Malaysia, Universiti Malaysia Sabah (UMS), Universiti Malaya (UM) and the Netherlands Centre for Biodiversity (NCB) Naturalis. The results show that Semporna rivals the top spots in the Coral Triangle in terms of coral, fish and shrimp taxa. However, the state of the reefs is worrying. Mushroom coral species (Family Fungiidae) were counted as a proxy for coral species richness. A total of 44 species were recorded from 63 sites. The mushroom coral species composition at each site was variable and depended on the reef condition. Species diversity was generally higher at reefs close to the mainland, with the highest diversity at Maiga Island (Site 41) in the Tun Sakaran Marine Park and Batik Kulambu Island (Site 53) in Darvel Bay. Both sites recorded 29 species. Semporna PCA shows two clusters of mushroom coraldistributions. The first cluster comprises the barrier reef area, Sipadan and some of the outer northeastern reefs. The second cluster centers around northwestern reefs and those of Darvel Bay and the Tun Sakaran Marine Park. The total of 44 species of mushroom corals that have been recorded from this expedition surpasses other areas with very high biodiversity in the Coral Triangle such as Berau, East Kalimantan and Raja Ampat, West Papua. Both of these sites recorded 41 and 40 species of mushroom corals, respectively, and to date Semporna holds the record for the highest species diversity of this coral family. The fish surveys also found high richness. The surveys focused on reef-dwelling fish and some pelagics as encountered in the Semporna fish markets. The total reef fish diversity of Semporna recorded during the roving surveys and rotenone stations consists of 690 species belonging to 265 genera and 72 families. The total number of species recorded from market surveys was 141, of which 78 were not recorded during the roving surveys, resulting in a combined diversity of 768 species for the entire expedition. Conventional methods of predicting fish richness indicates that Semporna may reach, with further surveys, 966 species. This puts Semporna in the top 5 sites in the Coral Triangle for fish richness. 2Other taxa surveyed included reef-dwelling shrimps, coral-dwelling gall crabs, and ovidulae snails. The surveys found 104 species of shrimps, which ties with Ternate, Indonesia as the highest in the Coral Triangle. The surveys of gall crabs and ovulidae have contributed to a growing literature on these relatively unknown taxa. The algae surveys found more than 130 species. Further confirmation of specimens is being conducted at Universiti Malaya. The distribution of algae around Semporna was highly varied with high richness found at reefs throughout the study area. Many of the taxa are considered rare within the Semporna PCA. The reef status team surveyed 106 transects at 60 sites. Using a modified version of the standard Reef Check methodology, they assessed substrate cover, fish densities, invertebrate densities, and impacts. The results show that for substate cover, only 5 stations out of the 109 (5%) are found to be ‘Excellent’, 25 stations (23%) ‘Good’, 41 stations (38%) ‘Fair’ and 38 stations (35%) are at ‘Poor’ status. The fish density surveys showed low densities of nearly all indicator groups including snapper, parrotfish, humphead wrasse, and groupers. 3