TY - JOUR
T1 - A case study on fuel oil contamination in a mangrove swamp in Hong Kong
AU - Tam, Nora F.Y.
AU - Wong, Teresa W.Y.
AU - Wong, Y. S.
N1 - Funding Information:
The work described in this paper was fully supported by a grant from the Research Grant Council, HKSAR (Ref. no. CityU 1110/02M). The authors gratefully acknowledge Mr. Benz Chan for his assistance in the GC analyses.
PY - 2005
Y1 - 2005
N2 - Mangroves commonly found along tropical and subtropical coastlines are susceptible to oil pollution. In December 2000, around 500 1 m tall Kandelia candel saplings at the age of 3-5 years old located at the foreshore region of Sheung Pak Nai swamp, Hong Kong SAR, were found to be damaged by oil pollution. More than 80% of the saplings were either dead or washed away and leaving less than 5% healthy saplings with dense green leaves. Elevated concentrations of light n-alkanes (ranging from n-C14 to n-C20), pristane and phytane were recorded in surface sediments collected in December 2000. The ratio between light and total n-alkanes was 0.4. The total petroleum hydrocarbons (60-80 μg g-1 TPH) and unresolved complex mixtures (60-70 μg g-1 UCM) were higher than the background values of other mangrove sediments in Hong Kong, which were 40 and 20 μg g-1, respectively. In certain root zone sediments, TPH concentrations were above 1000 μg g-1. These results suggest that surface sediments in Sheung Pak Nai were contaminated by petroleum oil, most likely by illegal discharge of fuel oil which occurred between 1998 and 2002. One year later, in December 2001, unhealthy saplings had recovered and re-grown. The concentrations of TPH and UCM in sediments declined to around 40 μg g-1, pristane and phytane dropped by 80%, and the ratio of light to total n-alkanes was 0.15, suggesting that residual oil in sediments was weathered leading to a remarkable recovery of the unhealthy saplings.
AB - Mangroves commonly found along tropical and subtropical coastlines are susceptible to oil pollution. In December 2000, around 500 1 m tall Kandelia candel saplings at the age of 3-5 years old located at the foreshore region of Sheung Pak Nai swamp, Hong Kong SAR, were found to be damaged by oil pollution. More than 80% of the saplings were either dead or washed away and leaving less than 5% healthy saplings with dense green leaves. Elevated concentrations of light n-alkanes (ranging from n-C14 to n-C20), pristane and phytane were recorded in surface sediments collected in December 2000. The ratio between light and total n-alkanes was 0.4. The total petroleum hydrocarbons (60-80 μg g-1 TPH) and unresolved complex mixtures (60-70 μg g-1 UCM) were higher than the background values of other mangrove sediments in Hong Kong, which were 40 and 20 μg g-1, respectively. In certain root zone sediments, TPH concentrations were above 1000 μg g-1. These results suggest that surface sediments in Sheung Pak Nai were contaminated by petroleum oil, most likely by illegal discharge of fuel oil which occurred between 1998 and 2002. One year later, in December 2001, unhealthy saplings had recovered and re-grown. The concentrations of TPH and UCM in sediments declined to around 40 μg g-1, pristane and phytane dropped by 80%, and the ratio of light to total n-alkanes was 0.15, suggesting that residual oil in sediments was weathered leading to a remarkable recovery of the unhealthy saplings.
KW - Alkane
KW - Fuel oil
KW - Kandelia candel
KW - Petroleum hydrocarbons
KW - UCM
UR - http://www.scopus.com/inward/record.url?scp=27744581699&partnerID=8YFLogxK
U2 - 10.1016/j.marpolbul.2005.06.005
DO - 10.1016/j.marpolbul.2005.06.005
M3 - Article
C2 - 16023144
AN - SCOPUS:27744581699
SN - 0025-326X
VL - 51
SP - 1092
EP - 1100
JO - Marine Pollution Bulletin
JF - Marine Pollution Bulletin
IS - 8-12
ER -