辽东湾水体中石油类的时空分布特征和污染状况

Temporal and Spatial Distribution of Petroleum Hydrocarbon and the Pollution in Seawater of the Liaodong Bay

关键词:  辽东湾，石油类，分布特征，变化趋势

Key words:  Liaodong Bay  Petroleum hydrocarbon  Distribution characteristics  Change trend

摘要:

根据2013-2014年春、夏、秋、冬季对辽东湾海域8个航次的调查资料，研究了水体中石油类的空间分布特征及季节变化趋势，分析了其污染状况，探讨了其污染来源。结果显示，辽东湾海域海水石油类含量范围为(0.003–0.239) mg/L，平均为0.027 mg/L，随着季节周期性变化波动，整体呈下降的变化趋势；春、秋、冬季各航次均存在不同程度的海水水质超标准现象，表底层石油类含量存在显著相关性，具有秋季>冬季>春季>夏季的季节变化趋势，石油类含量呈沿岸高于远岸，开放海域大于海洋保护区的平面分布特征。深入分析发现，石油类含量范围为0.030–0.032 mg/L，分布区域面积最广，为6960 km2，占调查海域的27.0%；集中分布在辽东湾北部沿岸和西部近岸海域。石油类含量低于0.024 mg/L的区域分布面积为2806 km2，占辽东湾调查面积的10.9%，分布区域主要集中在大连斑海豹国家级自然保护区范围内。石油类含量高于0.032 mg/L，区域分布面积为1170 km2，仅占辽东湾调查面积的4.5%，集中分布在辽东湾西部沿岸港口区海域。季节变化主要受机动渔船海上作业污染影响；陆源输入和人类海上活动的输入为辽东湾海域石油类主要来源。

Abstract:

Here we studied the seasonal, temporal and spatial distribution of petroleum hydrocarbon in the Liaoning Bay based on the all-year-around environmental monitoring data in 2013 and 2014. The source and degree of pollution were also analyzed and discussed. The range of petroleum hydrocarbon concentration in seawater was 0.003-0.239 mg/L with an average of 0.027 mg/L. The concentration tended to decrease over time and exhibited seasonal fluctuation. Petroleum hydrocarbon concentrations in spring, autumn and winter exceeded the limit of the national benchmark with varying degrees. There was a significant correlation between concentrations in the surface and bottom seawater. The petroleum hydrocarbon concentration varied in seasons (autumn > winter > spring > summer), and gradually decreased from inshore to offshore, and from open areas to protected areas. It could be concluded that regions with petroleum hydrocarbon concentrations of 0.030-0.032 mg/L, < 0.024 mg/L, and > 0.032 mg/L accounted for 27%, 10.9%, 4.5% of the total investigated sea area respectively. The region with a concentration of 0.030-0.032 mg/L had an region of 6960 km2 and was mostly within the northern and western coastal region of the Liaodong Bay. The area with petroleum hydrocarbon concentration below 0.024 mg/L was 2806 km2 and was mainly located in the Dalian harbor seal nature reserve. The smallest area was about 1170 km2 in the western harbor area of the Liaodong Bay. Analysis also showed that seasonal variation in petroleum hydrocarbon concentration was affected by the pollution from fishing vessel operations, and that the major sources of petroleum hydrocarbon were the terrestrial inputs and marine anthropogenic activities.