Contamination of Heavy Metals in Marine Sediment Cores from Victoria Harbour, Hong Kong PETER A. TANNER *, LAI SHING LEONG 1,  and SHAO MING PANà  Centre for Coastal Pollution and Conservation, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR àState Pilot Laboratory of Coast and Island Exploitation, University of Nanjing, Nanjing 210008, People's Republic of China The physical characteristics, and concentrations of major and trace metals, in 6 m long sediment cores from ®ve marine locations in Hong Kong have been determined. Core chronologies have been reconciled with dredging, construction, and other anthropogenic activities taking place since 1900. Sedimentation rates varied by an order of magnitude, from the more open harbour environments to enclosed ones. The most critical pollutant in the cores, copper, had normalized enrichment factors between 2.8 and 312 at the ®ve sites, and sur®cial concentrations >6 g kg 1 in the upper sediment of the Typhoon Shelter sampling site. Whereas the Cu, Ni and Cr pollution largely dates from the post-industrial period, Zn and Pb pollution have a longer history from the construction, maintenance and anchorage of ships. Individual trace metal ¯uxes varied from one location to another by factors >1500, and the magnitudes in the Typhoon Shelter were generally greater than values at other polluted harbour environments. Ó 2000 Elsevier Science Ltd. All rights reserved. Keywords: metals; sediment; vibrocores; Hong Kong; Pb-210; ¯uxes. Introduction In the present study, we have investigated the history of the pollution of recent sediments along the coastal area in Victoria Harbour, Hong Kong, by using the Pb-210 dating method. This has proved to be dicult because most settings have been disturbed. However, it will not be possible to repeat this study in future since reclamation or construction is planned or taking place at the sampling locations: irreversibly and for- ever changing the harbour characteristics. For most cores, the Pb-210 data serve to provide the boundaries for undisturbed sediment regimes in the cores. In or- der to explain the abundance of metals in the sediment cores, we have therefore supplemented this with de- ductions from physical characteristics and observa- tions, as well as turning to historical records. No previous vertical studies have been carried out within Victoria Harbour, and the urban and industrial de- velopments in this crowded location have taken place on a comparatively recent timescale, eminently suitable for reconstruction from sediment Pb-210 data. The rapid growth of Kowloon occurred after the 99-year lease of the New Territories in 1898 with light indus- tries ¯ourishing. Manufacturing industries, such as electroplating, dyeing and printed circuit board (PCB) manufacture, developed with the in¯ux of population and manufacturing facilities, after the low level of entrep^ ot trade during the 1950s, and were mainly sit- uated at near-coastal locations in Hong Kong. Many of these heavy industries relocated to China in the 1980±1990s. Hong Kong is the worldÕs busiest container port. Some of its dynamism and problems have been the subject of a recent editorial (Morton, 1998). It only occupies a total area of 2500 km 2 , including land and sea, being situated between latitudes 22°90 0 and 22°37 0 N, and longitudes 113°52 0 and 114°30 0 E (Fig. 1). Its natu- rally deep harbour lies at the eastern edge of the Zhujiang (Pearl River) estuary. The marine environment of Hong Kong and the hydraulics conditions have been described by Watts (1973) and Ip (1996). ManÕs in¯u- ence on Victoria Harbour is signi®cant: reclamation activities have been extensive (Fig. 2). Not only has this changed the coastline seaward, but it has also aected the sedimentation process in the harbour, with for Marine Pollution Bulletin Vol. 40, No. 9, pp. 769±779, 2000 Ó 2000 Elsevier Science Ltd. All rights reserved Printed in Great Britain 0025-326X/00 $ - see front matter PII: S0025-326X(00)00025-4 *Corresponding author. Tel.: +852-2788-7840; fax: +852-2788- 7406. E-mail address: bhtan@cityu.edu.hk (P.A. Tanner). 1 Present address: Technology Transfer Group, Environmental Management Division, Hong Kong Productivity Council, 78 Tat Chee Avenue, Kowloon SAR, Hong Kong. 769