Abstract:

Eighteen years of monitoring data at four sections along the coastline of Taisi Township, Yunlin County, between 1993 and 2010 were used to study the effects of power plant on plankton. Sampling was conducted at depths of 10 m and 20 m in each section. Among the four seasons, the fourth quarter (October to December) had the lowest average abundance of plankton over the years. However, the peak abundance of different types of plankton occurred in different seasons. Zooplankton had the highest abundance during the first and second seasons (January to June) while phytoplankton, shrimp larvae and crab larvae had the greatest abundance in the 2nd quarter (April to June) and the peak in fish egg and fish larvae occurred from the 1st to the 3rd quarter (January to September). Cumulative data from 18 years shows that the pH of SEC5 often dipped below 7.8 since the 3rd quarter of 2000. pH value lower than 7.8 were frequently measured in the stations of section 5. Each time the pH value is under 7.8, the quantities of zooplankton (75±69 ind./m³), phytoplankton ((1.60±2.28)×10³ cell/L), shrimp larvae (2.4±5.8 ind./m³), crab larvae (1.9±5.0 ind./m³), fish egg (0.88±1.10 ind./m³), and fish larvae (0.16±0.32 ind./m³) showed significant low values (only the half of the total average). Accordingly, we strongly suggest that the warm water effluents discharging from a power plant should maintain the pH above 7.8 in the coastal waters to reduce the negative impact on the marine zooplankton biodiversity and abundance.

Key words: pH, plankton, Yunlin coast, ocean acidification, flue gas desulphurization (FGD)