Abstrak
SUMMARY This study aims to analyze the phytoplankton concentration of potential species that give rise to HAB's in supporting the management of the potential of fishery resources on the coast of Kupang Bay. This research has been carried out in the waters of Kelapa Lima, the estuary of the Oesapa River (Pohon Duri) and the estuary of the Tarus River (Manikin Beach) from May to June 2018. The collection of water samples in the waters from the coastline taken using a modified Nansen bottle with a volume of 10 liters and repeating 50 liters vertically representing the surface, mid and bottom of the waters. The samples obtained were filtered using 20 μm of plankton-net, with a concentration formalin of 4%. The composition of HAB's species of phytoplankton found in Kupang Bay waters consisted of 19 species namely PSP 1 species, DSP 2 species, NSP 1 species, ASP 1 species, CFP 4 species, Red Tide 9 species and Anoxia and Hypoxia 7 species. The total abundance of overall phytoplankton HAB's potential species in the waters of Teluk Kupang ranged between 1052.8-5760 cells/L divided into groups of toxin-producing phytoplankton 11 species (1017.6-5734.4 cells/L) and phytoplankton groups causing Red Tide 9 species (25,6-1033,6 cells/L). HAB's species phytoplankton species diversity index (H') in these three locations is high, evenly distributed species (E) and no species dominates (C). The predominantly potential phytoplankton species of HAB consists of 4 species, Trichodesmium erythraeum and Trichodesmium thiebautii from the Cyanobacteria class, whereas from the class Bacillariophyceae (Diatom) consists of Skeletonema spp. and Chaetoceros spp. In the Tarus waters (Manikin Beach) have experienced the bloom of Trichodesmium erythraeum and in the waters of Oesapa (Pohon Duri) have experienced the bloom of Trichodesmium thiebautii.