Effects of oil spill in meiobenthic community in tidal zone of the Yellow sea, Korea

Abstract

Hebei Spirit laden with 263,944 tons of crude oil was struck by the crane barge belong to Samsung Heavy Industries Co., on 7 December 2007. The spot where the accident took place is about five miles off Taean on the west coast of the Republic of Korea. About 10,900 tons of crude oil spilled into the sea from the Hebei Spirit. The farms and beaches along the western coast of the Republic of Korea were contaminated by crude oil. Meiobenthic animals were collected in Jan., Apr. and Sep., 2008 in the upper, central and lower part of the tidal zones (st.1 Iwon, st.2 Shindoori, st.3 Manripo, st.4, Yeonpo, st.5 Mongsanpo, st.6 Baramarea). One of meiofaunal samples were collected in every month for six month on st.2, 3 and 4. Samples for quantitative analysis were collected by a diameter 2.6 ㎝ plastic syringe. The obtained samples were sliced at 1 cm depth intervals from the surface to 5 cm (0~1 ㎝, 1~2 ㎝, 2~3 ㎝, 3~4 ㎝ 4~5 ㎝), and then fixed with 5% neutralized formalin mixed with Rose Bengal. The samples were size fractioned with variable mesh aperture sieves (1 ㎜, 500 ㎛, 250 ㎛, 125 ㎛, 63 ㎛ and 37 ㎛), and then animals were identified and counted under a stereo-microscope. Because more than 90 % of the meiobenthos were found within upper 3 cm, horizontal abundance of meiobenthos presented was evaluated from the data gained from the upper 3 cm interval. Taxonomical density of meiobenthos were not uniform in each survey sites. The average density of meiobenthic animals were determined to be at 1~1,609 ind./10㎠ in the tidal survey sites (6 sites, 18 stations). The minimum density of meiobenthos is in the central part of Manripo (st.3) on Jan., 2008. The maximum density of meiobenthos is in the lower part of Yeonpo (st.4) on Jan., 2008. Taxonomical composition was represented by 1~13 taxa/10㎠ in the tidal survey sites (6 sites, 18 stations). The minimum number of groups is in the central part of Manripo (st.3) on Jan., 2008. The maximum number of groups is in