CHANGE IN ENERGY CONTENTS IN THE MANILA CLAM, Ruditapes philippinarum EXPOSED TO CRUDE OIL CONTAMINATED SEDIMENTS.

Chan-Gyung Sung*, Chang-Hoon Lee, Ji-Hye Lee, and Jong-Hyeon Lee
 
NeoEnBiz Co., Institute of Environmental Safety and Protection,
DeawooTechnoPark, 216, Doyak-ro
Bucheon, Kyeonggido, Republic of Korea, 420-806
neocgsung@gmail.com
 

Manila clam Ruditapes philippinarum is widely cultured in tidal flats along the western- and southern coasts of Korea. Many of aquafarms locates adjacent to harbors and urban areas so that they are highly vulnerable to various environmental contaminations including oil spill accidents. For example, a large-scale oil spill accident occurred in 2007 in the west coast of Korea. Spilled oil covered ca 375 km of shoreline and more than half of the aquafarms lost their stocks.

In this study, we evaluated the effects of oil contamination on the growth potentials in the Manila clam, Ruditapes philippinarum. Clams were exposed to various level of contamination for 14 days. The contents of protein, lipid, and glucose in the foot, siphon, gill, and body were measured. The weight contents were converted to the energy contents. The energy consumption was also measured.

As exposure time and the concentration level increased, the content of protein, lipid and glucose decreased, whereas the energy consumption increased. The ranges of energy contents in foot, siphon, gill and body were 4800-12200, 4100-13200, 3400-7400 and 2600-9300 mJ/mg, respectively. One day after exposure, the energy contents significantly decreased in foot and gill. The energy contents in body significantly decreased at 2 and 7 days after exposure. The energy consumption most increased in body. It significantly increased 4 days after exposure at a maximum concentration of 58.3 mg/kg dw, which is commonly detected at contaminated sediments around oil spill areas.

From the results of this study, we found that oil contamination can affect the growth potential of Manila clam. In extreme cases of oil spill, many of organism face to death. However, low contamination level does not apparently give fatal effects, the decrease in the amount of body components, which may in turn affect the energy metabolism and growth.