A Gary-O’Hara box corer (0.15 m2) was used to collect sediment
samples and matched macrobenthic samples. Sixteen sampling
stations plus one reference station were located throughout the
Bay (Fig. 1), with an emphasis on the southwest stations affected
by the Huanghe River and Xiaoqing River. The reference station
(C5) was situated in the northeast part of the surveyed area near
the middle of the Bohai Sea, because this location was far from
the Huanghe River mouth and south bank of Laizhou Bay and thus
relatively unaffected by anthropogenic and natural stressors. Sediments
at all locations, with water depth ranging from 3.0 to
15.5 m, were sampled in quadruplicate. Sediments from the top
10 cm of the first sample, which usually correspond to the living
space of benthic organisms, were collected for chemical measurements.
The sediments were divided into three sub-samples for
determination of geochemical parameters, including grain size
and the contents of total organic carbon (TOC), metals and petroleum
hydrocarbons (PHs). These subsamples were then stored at
20 C. Due to intensive oil exploitation and shipping-related
activities (Wang et al., 2007), PHs were analyzed as a potential