The Microalgal Attachment and its Growth on the Artificial Surfaces Immersed in Seawater: II. Chlorophyll a and Primary Productivity

To understand the growth of attached microalgae to the immersed artificial surfaces in seawater with exposure time, chlorophyll a (chl a) concentration and abundance of attached microalgae to glass slides, and primary productivity and chl a concentration on coverglasses were investigated in Incheon Harbour in May, June 1996 and January-February 1997. Chl a concentrations of microalgae and abundances of diatoms attached to glass slides reached 62.5 mg chl a and cells , respectively, during the study period. Chl a concentrations increased with exposure time, and they were significantly correlated with the abundances of attached diatoms (, p and 65.4 mg chl a , and then decreased in May, June 1996. But in January-February 1997, the chl a concentration increased continuously up to 98.9 mg chl a . The primary productivity reached the maximum values of 63.1 mgC , 347.0 mgC and 78.3 mgC , respectively, in May, June and January-February. The primary productivity in May and June varied in accordance with chl a concentrations. But in January-February, the primary productivity decreased from 26 days of exposure while chl a concentration continued to increase. Two cases that primary productivity decreased abruptly seemed to be caused by decrement of chl a and light specific (chl a specific primary productivity) (May and June) and by decrement of light specific due to photoinhibition (January-February). The results of present study indicated that chl a concentrations and the primary productivity of microalgae attached to artifical surfaces immersed in seawater would expedite analysis of dynamics of biomass and physiological status of attached microalgae during biofilm formations.