Murphy Kathleen R, Ruiz Gregory M, Dunsmuir William T M, Waite T David
Smithsonian Environmental Research Center, P.O. Box 28, Edgewater, Maryland 21037, USA.
Environ Sci Technol. 2006 Apr 1;40(7):2357-62. doi: 10.1021/es0519381.
Mid-ocean ballast water exchange is mandatory for ships discharging foreign ballast in US territorial waters in order to reduce the risk of biological invasions. However, a reliable tool for determining whether the procedure took place is lacking. We investigated chromophoric dissolved organic matter (CDOM) fluorescence as a tracer of mid-ocean exchange on nine research cruises out of Asia, Europe, and the USA, focusing on challenging source conditions (high salinity, low CDOM). Using parallel factor analysis, we identified nine independent fluorescent components present in varying concentrations in the ocean and in ballast water. One component was sufficient for predicting the coastal vs oceanic source of most ballast water samples. Across nine cruises, thresholds (1.7 and 0.7 ppb quinine sulfate equivalent units) at two fixed wavelength pairs (lambda(ex)/lambda(em) = 320/414 and 370/496 nm, respectively) discriminated coastal from oceanic ballast water in > 95% of samples (N = 514). Our results suggest that single- and dual-channel fluorometers could be optimized for verifying ballast water exchange.
对于在美国领海排放外国压舱水的船舶，在大洋中部进行压舱水交换是强制性的，以降低生物入侵的风险。然而，目前缺乏一种可靠的工具来确定该程序是否已实施。我们在来自亚洲、欧洲和美国的9次研究航行中，研究了发色溶解有机物（CDOM）荧光作为大洋中部交换的示踪剂，重点关注具有挑战性的源条件（高盐度、低CDOM）。通过平行因子分析，我们确定了海洋和压舱水中存在的9种独立荧光成分，其浓度各不相同。其中一种成分足以预测大多数压舱水样本的沿海或海洋来源。在9次航行中，两个固定波长对（分别为λ（ex）/λ（em）= 320/414和370/496 nm）处的阈值（1.7和0.7 ppb硫酸奎宁当量单位）在超过95%的样本（N = 514）中区分了沿海压舱水和海洋压舱水。我们的结果表明，单通道和双通道荧光计可以进行优化，以验证压舱水交换。
