Abstract:
Hydrooceanographic factors influence the plankton occurrence. These are aquatic
environmental parameters that take important role in plankton community structure. This study was
aimed at knowing the effect of the hydro-oceanographic factors on the abundance and the diversity of
plankton in the natural coral reef ecosystem and the artificial reef in the waters of Steam-Based-Electric
Power Plant (SBEPP), Paiton. It employed quantitative analysis and Principle Component Analysis (PCA)
method. Results showed that the phytoplankton abundance in the natural coral reef ecosystem ranged
from 3,209 to 5,589 cells L-1 and in the artificial reef from 598 to 856 cells L-1. Zooplankton abundance in
the natural coral reef and the artificial reef were 48-70 ind L-1 and 23-36 ind L-1 respectively.
Phytoplankton abundance in both localities was more than 500 cells L-1 reflected high fertility category of
the waters, while plankton diversity of both localities of 2.19-3.25 indicated moderate diversity. PCA
analysis showed that water brightness and pH were moderately correlated with plankton abundance and
diversity. Water salinity, dissolved oxygen (DO), and phophate were very strongly positively correlated
with plankton abundance and diversity, while water temperature and nitrate were very strongly
negatively correlated with plankton abundance and diversity. The latter in the natural coral reef is
indicated with increased plakton abundance in low nitrate and phosphate concentrations, while in the
artificial reef, the plankton abundance was low in the high nitrate and phosphate concentrations.
Key Words: plankton, coral reef, abundance, diversity, Paiton.
