Department of Environmental Science, Baylor University, One Bear Place #97266, Waco, TX 76798, USA; Institute for Biomedical Studies, Baylor University, One Bear Place #97266, Waco TX 76798, USA; Center for Reservoir and Aquatic Systems Research, Baylor University, One Bear Place #92766, Waco, TX, USA.
R.M. Parsons Laboratory, Department of Civil & Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Environ Pollut. 2018 May;236:609-618. doi: 10.1016/j.envpol.2018.01.086.
The industrialized portion of the Houston Ship Channel (HSC) is heavily contaminated with anthropogenic contaminants, most prominent of which are the polychlorinated biphenyls (PCBs). This contamination has driven adaptive evolution in a keystone species for Galveston Bay, the Gulf killifish (Fundulus grandis). We investigated the geographical extent of PCB impacts by sampling 12 sites, ranging from the heavily industrialized upper portion of the HSC to Galveston Island. At each site, PCB concentrations and profiles were determined in three environmental compartments: sediment, water (polyethylene passive samplers), and fish tissue (resident Gulf killifish). We observed a steep gradient of PCB contamination, ranging from 4.00 to 100,000 ng/g organic carbon in sediment, 290-110,000 ng/g lipid in fish, and 4.5-2300 ng/g polyethylene in passive samplers. The PCB congener profiles in Gulf killifish at the most heavily contaminated sites were shifted toward the higher chlorinated PCBs and were highly similar to the sediment contamination profiles. In addition, while magnitude of total PCB concentrations in sediment and total fish contamination levels were highly correlated between sites, the relative PCB congener profiles in fish and passive samplers were more alike. This strong correlation, along with a lack of dependency of biota-sediment accumulation factors with total contamination rates, confirm the likely non-migratory nature of Gulf killifish and suggest their contamination levels are a good site-specific indicator of contamination in the Galveston Bay area. The spatial gradient of PCB contamination in Galveston Bay was evident in all three matrices studied and was observed effectively using Gulf killifish contamination as an environmentally relevant bioindicator of localized contamination in this environment.
休斯顿航道（Houston Ship Channel，HSC）的工业化部分受到人为污染物的严重污染，其中最突出的是多氯联苯（PCBs）。这种污染推动了加尔维斯顿湾的关键物种——海湾食蚊鱼（Fundulus grandis）的适应性进化。我们通过在 12 个地点进行采样，从高度工业化的休斯顿航道上游部分到加尔维斯顿岛，调查了 PCB 影响的地理范围。在每个地点，我们都确定了三个环境部分（沉积物、水（聚乙烯被动采样器）和鱼组织（当地的海湾食蚊鱼）中的 PCB 浓度和分布。我们观察到 PCB 污染的急剧梯度，从沉积物中的 4.00 到 100,000ng/g 有机碳，鱼中的 290-110,000ng/g 脂质和聚乙烯中的 4.5-2300ng/g 聚乙烯。在污染最严重的地点，海湾食蚊鱼中的 PCB 同系物分布向高氯化 PCB 转移，与沉积物污染分布高度相似。此外，虽然沉积物中总 PCB 浓度和鱼类总污染水平之间的相关性很高，但鱼类和被动采样器中相对 PCB 同系物分布更为相似。这种强烈的相关性，以及生物-沉积物积累因子与总污染率之间缺乏依赖性，证实了海湾食蚊鱼可能是非迁徙性的，并表明它们的污染水平是加尔维斯顿湾地区特定地点污染的良好指标。在研究的所有三个基质中，都可以明显看到加尔维斯顿湾 PCB 污染的空间梯度，并且通过使用海湾食蚊鱼的污染作为该环境中局部污染的环境相关生物指标，有效地观察到了这种梯度。
