Tawi Tawi, Reef Fishes, Philippines

Study Extent

total of seventeen (17) stations were surveyed on April 10 to May 10, 2005. These sites were strategically located in the center of the Sulu Sulawesi large marine environment and politically part of the province of Tawi-tawi. Specifically, the stations were in Mapun (5 sites), Sitangkai (6 sites), and Languyan (6 sites). These are Linggisan, Tigul-tigul, Umus-umus Labuhan reef areas of the major island and the population center of Mapun, the Cagayan de Tawi-Tawi I. and the reef of Manda I. per recommendation of the Mayor of the Municipality. For Sitangkai Municipality, the survey sites were mostly located in the North Lagoon except for Lappasan which is in Tumindao channel but part of Barangay Tonggusong. The other sites in the North Lagoon are Sekorong, Andulingan or known as the “snake-island”, Kullul Pahi, Sanga-Sanga and Sipangkut reef. For Languyan Municipality, the sites surveyed were mostly reef areas of island sitios except for Languyan reef which is part of main island of Tawi-tawi and politically part of the municipality of Languyan. The surveyed islands were Tumbagaan, Sugbay, Basbas, Kangtipayan Heya and Diki, and Simalak.

Sampling

The survey of reef fishes was conducted along the same transects laid for coral assessment covering an area of 500m2 per transect line. Status of reef fishes, species diversity, fish abundances and estimated biomass were determined employing the standard fish visual census method modified from English et al. (1997). The standard protocol observed for all the selected sites was for the fish counters to identify encountered species and count fish numerically for every five 5m along each transect line, and within 5m on either side and above the substrate. All fish encountered within the area as described above were identified to the species level. Counts for abundances and size estimates (estimated total length) of target species (Lutjanidae, Haemulidae, Lethrinidae, Carangidae, Caesionidae, Nemipteridae, Mullidae, Scaridae, Acanthuridae, Epinephelidae and Siganidae), and indicator species (Chaetodontidae) were used as bases in determining fish biomass and density. The abundances of species belonging to families not included in the target and indicator species categories but numerically abundant were likewise recorded. Fish biomasses for all the species encountered were computed using known length-weight relationships (W=aLb) from Froese and Pauly (2000). Fish were identified using the works of Lieske and Myers (1994), Myers (1997), Randall et al. (1997) and Froese and Pauly (2000). Length-weight relationships of the form W = aLb from Froese and Pauly (2000) were used in computing fish biomass. Other relevant information such as reef fish density, species and status of coral reef fish biomass production (Aliňo and Dantis, 1999) were also determined.

Quality Control

Replicates of per site sampling were done

Method steps

1. None

Geographic coverage is on the selected municipalities of Tawi-Tawi, Philippines