Asia Pacific Journal of Multidisciplinary Research, Vol. 3, No. 5, December 2015 _______________________________________________________________________________________________________________ 110 P-ISSN 2350-7756 | E-ISSN 2350-8442 | www.apjmr.com Mollusks in the Mangrove Rehabilitation Areas in Western Pangasinan, Philippines Rene B. De Vera, Irene A. De Vera 1 and Raul Dela Peña Pangasinan State University Binmaley Campus, Binmaley, Pangasinan 2417, Philippines lijerenai@yahoo.com 1 Date Received: October 30, 2015; Date Revised: December 19, 2015 Asia Pacific Journal of Multidisciplinary Research Vol. 3 No.5, 110-115 December 2015 Part III P-ISSN 2350-7756 E-ISSN 2350-8442 www.apjmr.com Abstract-Mollusks are predominantly found inmangrove ecosystems. Nowadays, these are declining due to habitat disturbances. This study was conducted in Western, Pangasinan, with mangrove rehabilitation projects under Community Based Forest Management Agreement. Four mangrove rehabilitation areas were looked into: Pilar and Victory, Bolinao; and Awile and Tori-tori, Anda, Pangasinan. Purposive sampling was done in selecting the mangrove rehabilitation areas. Ten percent sampling of the areas using the belt transect quadrat method was employed. Diversity, dominance , richness and evenness indices for mollusks were determined. Mann Whitney test, Student’s t-test and Kruskal Wallis test were used. A total of fourteen kinds of mollusks species were identified. The species were Tectusfenestratus (fenestrate top), Terebraliasulcata (Sulcate swamp perith), Haliotisovinagemelin (o val abalone), Neritaplanospiraanton (flat spired nerite), Clithionoualensis(dubious nerite), Fasciolaria trapezium (trapezium horse conch), Nasarriuspullus (ribbed dog whelk), Trochusmaculatus (maculated top), Rhinoclavisvertagus (Common vertagus ), Telescopium telescopium (Telescope Snail), Isognomonephippium (saddle tree oyster) Crassostriairedali (slipper oyster), Strombuslabiatus (Plicate conch) and Polymesodaexpansa (Yellowish mangrove clam). The highest mollusks species diversity and richness indeces were observed in Victory, Bolinao. Mollusks species dominance and evenness indeces were highest in Pilar, Bolinao and Tori-tori, Anda, respectively. The study revealed a significant difference in the probability of gathering mollusks species in the four mangrove rehabilitation areas. It is recommended that fisherfolkand coastal communities be educated about the need for mollusks conservation and habitat protection. It is expected that this study may provide light to future research on mangrove fauna particularly mollusks in Pangasinan. Keywords- species diversity, dominance, evenness and richness INTRODUCTION Mollusks is one of the two classifications of shellfish (the other being crustacean) which is considered to be the second most diverse group of animals in terms of number. They are very susceptible to changes in their environment because of their soft body with shell and permeable skin. However, they can be found in various habitats. Mangroves is one of the habitats of the mollusks. Nowadays, however, mollusks are declining due to habitat disturbances by dams, pollutions and indirectly from the abuse of terrestrial habitats. Several management approaches and methods are used to control or minimize its habitat destruction. One approach to bring back the habitat of marine species, mollusks in particular, is mangrove rehabilitation. This approach could be carried out by an organized community and the Department of Environment and Natural Resources (DENR) through entering into a production sharing agreement called community based forest management agreement (CBFMA).A specific portion of mangrove forest land will be granted to the community for 25 years to develop, utilize, manage and conserve consistent with the principles of sustainable development[1]. Pangasinan has an estimated old stand of mangroves of 283hectareslocated along the coasts of Bolinao, Bani, Alaminos City, Anda, Dasol, and Infanta[2]. The mangroves estimated to be 990 in hectares in 1978[2]. Majority of these old stand areas were already fragmented due to natural and anthropogenic disturbances. In 1960, large mangrove areas were converted into fishponds for the culture of