One of the fisheries resources in the coastal area of Labakkang, Pangkep Regency, is bivalve
which mostly found in seagrass ecosystem. A study on bivalves of seagrass ecosystem was conducted
based on seasons, July to September 2013 (dry season) and January to March (rainy season). It was
aimed at knowing the bivalve diversity in relation with seasons. The study used a quadratic transect
method from the coastal line seawards to the end of seagrass population. Results show that there were
found 323 individuals of 17 species in dry season and 216 individuals of 14 species in rainy season.
Anadara sp. (Arcidae), Marcia hiantina and Anomalodiscus squamosus (Veneridae) are dominated species
in that area. Ecological index in either dry or rainy seasons showed that species diversity was moderate
(1.832-2.235) that the ecosystem has got pressures, while the eveness index was even enough and
there was no species dominance despite some species found in high abundance. Environmental
parameters could still be tolerated by the bivalves, and other marine biota.
Key Words: species diversity, bivalve, season, environmental parameters.