ASOSIASI GASTROPODA TERHADAP KERAPATAN LAMUN (SEAGRASS) DI PERAIRAN PESISIR DESA LABUHAN, KECAMATAN SEPULU, KABUPATEN BANGKALAN

Abstract

Gastropods are molluscs (soft-bodied) animals that have shells and move with their stomachs. Gastropods can be associated with seagrass ecosystems, because they provide food, spawning, breeding and shelter from predators. Seagrass conditions can influence the level of abundance and types of gastropods in the water. This study aims to determine the association of gastropods with seagrass density. The method used in the research is the purposive sampling method, using a 1 x 1 m quadrant transect. The results of the research were that the gastropods found on the Coast of Labuhan, Sepulu, Bangkalan were the Clypeomorus bifasciata type with the highest abundance of 301.5 ind/m2, while the lowest abundance of gastropods were Coralliophila caribaea, Cypraea dillwyni, Nerita planospira with a value of 0.5 ind/m2. The diversity index (H') value in the "medium" category is around 1.115-1.35, the uniformity index (E) is "low" around 0.25-0.28 and the dominance index (C) is "medium" around 0.39- 0.44. One type of seagrass was found, namely Thalassia hemprichii, with a density of between 50-61 ind/m2 in "rare" conditions. The association of gastropods with seagrass density obtained a Pearson Product Moment correlation value of 0.684, including the criteria for a strong relationship, with the calculated r value being higher than the r table (0.684 > 0.666). This is confirmed by the t test where the calculated t is higher than the t table (2.480 > t table 2.365), thus proving that there is a strong and unidirectional association between gastropods and seagrass density, meaning that the higher the seagrass density, the stronger it is to support a high gastropod density.