Abundance and distribution of sea urchins (Echinoidea Leske, 1778) on coral reefs in the waters of Latondu Island, Taka Bonerate, South Sulawesi, Indonesia

Sea urchin is one of the key biota of coral reef stability. Research on the abundance and distribution of urchins was carried out from January-August 2019 and field data retrieval occurred in March 2019 on Latondu Island, Taka Bonerate. This study aims to determine the relationship between sea urchin abundance with coral reef conditions and sea urchin distribution patterns in the waters of Latondu Island, Taka Bonerate. Observation of coral reefs and sea urchins was carried out at 3 stations with different criteria of coral reef conditions. Retrieval of coral reef data was done using the Point Intercept Transect (PIT) method, while sea urchin observation came about via a transect belt method. The results showed that in the waters of the island of Latondu, there were 133 sea urchins from 7 species of the Echinoidea class, namely Diadema setosum, Diadema antillarum, Echinometra mathaei, Echinotrix calamaris, Mespillia globulus, Heterocentrotus mammillatus and Echinotrix diadema. The largest abundance of sea urchins was found in Station 3 on the southern part of Latondu Island with 12 ind / 50m2, while Station 1 in the northeast and Station 2 in the northwest part showed 5 ind / 50m2. Sea urchin distribution at Station 1 with a value of 0.79 was uniform, Station 2 with a value of 0.80 was also uniform and Station 3 with a value of 0.91 was uniform as well. The relationship between Sea urchin and coral reef was 0.56, which meant the relationship was moderate and directly proportional