Zooplankton abundance during the transition and southeastern monsoon season in the Liang coastal waters, Ambon P. Pitriana (1*), H A Mulyadi (2), M S Abdul (3), W Purbiantoro (3), A Basit (4)
1. Research Center for Biosystematics and Evolution, National Research and Innovation Agency (BRIN) - Indonesia
2. Research Center for Oceanography, National Research and Innovation Agency (BRIN) - Indonesia
3. Research Center for Deep-sea, National Research and Innovation Agency (BRIN) - Indonesia
4. Research Center for Climate and Atmosphere, National Research and Innovation Agency (BRIN) - Indonesia
Abstract
Knowledge of the zooplankton communities, including their interactions with ocean physics, is essential to better understanding the marine environment. In this study, we observed an abundance of zooplankton during the transition period (April - May) and early southeastern monsoon (June) in the Liang coastal waters, Ambon Moluccas - Indonesia. The abundance of zooplankton has been determined using NORPAC net (0.33 mm mesh size) with a sampling depth from the sea surface to 15 meters. In addition, we also measured ocean physics parameters, such as temperature, salinity, dissolved oxygen, phosphate-P, and nitrate-N. Results suggest that the average zooplankton abundance in the transition period (April) was 1,680 individuals/m3, with the most dominant zooplankton was Larvacea (Appendicularia). While in May, the average zooplankton abundance was 3,964 individuals/m3, and copepod Acrocalanus sp. was the most abundant zooplankton. During the southeastern monsoon (June), the abundance of zooplankton slightly decreased to 3,771 individuals/m3, with the most plenteous zooplankton was Larvacea (Appendicularia). Moreover, copepod Rhincalanus was only identified in April and did not found in May and June. Furthermore, Pyrocypris sp., Acetes sp., Mysis sp., and Leptochela larvae were present during May and absent in two periods of the observations. In contrast, Cephalopoda larvae tended to occur only in June.
