||The west coast of Taiwan is densely populated with frequently activities for industrial and economic developments. The area is also the site with the existence of Chinese White Dolphin (CWD). Because the arising of ecosystem conservation, the government has attempted to promote the west coast as the marine protected areas (MPAs) for the CWD. Nevertheless, it is required to assess changes of environmental condition and marine environmental quality around the area before the establishment of marine protected areas to the site. If ineffective monitoring is implemented, then the establishment of marine protected areas will be no use.|
This study was initiated to assess the marine environmental condition by collecting and surveying the long term monitoring data that were published under the government reports and documents to assess the temporal and spatial trends of environmental factors. The data consists of rivers, trench, and marine water or sediments. The study areas covered Taichung County to Yunlin County. The methods for assessing the environmental quality included the use of geographic information system (GIS) for the biological distribution, regression analysis for the trend monitoring of chemical contaminants and physical environmental factors between 2001 – 2010 year surveys. The overall environmental quality within the studied sites were further evaluated for the river pollution index (RPI) and the habitat suitability index (HSI).
The survey results of 10 years river monitoring from Taichung to Yunlin showed that Hsin-Huu-Wei River belong to serious pollution with RPI 6.67 value. Yuanlin drainage, one of the six drainages of Chang Hua Coast Industrial Park, belongs to serious pollution with RPI 6.08 value. The RPI results of Six trenches around the Chang-Hua Coast Industrial Park showed that Tien-Wei trench 2, Lun-Wei trench 1, and Ji-An trench belong to mid level of pollution (RPI 3.7~3.975).
In the marine water survey, the results showed that the pH values were found lower at southern-ward monitoring station nearby the Formosa Petrochemical Corporation No. 6 Naphtha Cracking Industry site. The nitrogen-NH3 concentrations were found high in Jhuo-Shuei River and No. 6 Naphtha Cracking industry. The concentration of Chlorophyll-a was high in Chang-Hua Coast Industrial Park. In the survey of sediment, Hsin-Huu-Wei River arsenic concentration (As) was over the EPA guidelines, but the concentrations of Cr, Cu, Pb, Zn were within the level of required limits. In the biological survey, the results showed that abundance and species were not evenly distributed with non-comprehensive trends related to the environmental condition or changes. These indicated that biological monitoring survey displayed less important than physical and chemical monitoring for the assessment of man-made pollution or environmental impact from the industrial activities.
Overall the monitor sites of river, drainage and trench were differed without a consistent sampling scheme. The offshore sites were sampled greatly in distance, i.e. the farthermost point at four sea miles that had caused difficulties for the comparison of data results collected in different time. It is very uneasy to evaluate the pollution monitoring results. Thus, it is required to develop a long-term environmental quality monitoring plan for the assessment of water quality and sediment of river and marine water with appropriate / consistency sampling method, monitor time and site scheme. Finally, the relevant authorities should implement river remediation to improve the pollution and thereby to maintain the sustainability of marine environment. It is required to establish an integral monitoring program consisting of water and sediment and bio-monitoring in rivers, estuary, and marine to better predict the marine environmental quality. Also the integral and long-term monitoring program should ensure to predict the changes of west coastal and to achieve the effectiveness of marine environment.