溢油胁迫下孔石莼碳氮稳定同位素的变化

为了研究溢油对海岸潮间带重要的大型绿藻孔石莼（Ulva Pertusa）的影响，本文探究了在180#燃料油的原油分散液（WAF）胁迫下，孔石莼的生长速率、叶绿素a以及碳氮稳定同位素的变化。在低WAF浓度（1.43 mg/L、2.87 mg/L和4.30 mg/L）胁迫下，对孔石莼的生长具有促进作用，生长速率均高于对照组，同时叶绿素a和碳氮稳定同位素均呈现上升的趋势；而高浓度WAF（5.72 mg/L和7.17 mg/L）会抑制藻类生长，导致生长速率低于对照组，而叶绿素a含量却高于对照组，孔石莼的δ15N和δ13C相比对照组偏负。对于孔石莼来说，C、N稳定同位素变化的趋势比叶绿素a更明显，这表明在溢油胁迫下，孔石莼的C、N稳定同位素能够更好更快速地评价溢油胁迫毒性大小，因此可以作为海洋环境监测和评价的一种新手段。

Effect of oil spill stress on carbon and nitrogen stable isotope of Ulva Pertusa

In order to study the impact of oil spills on the Ulva Pertusa, one of the major macroalage in the intertidal zone of the coast, this study measured the growth rates, chlorophyll a as well as the carbon and nitrogen stable isotope of U.Pertusa under the stress of the water accommodated fraction (WAF) of 180# fuel oil.At the low WAF concentrations (1.43 mg/L, 2.87 mg/L and 4.30 mg/L), the growth rates of U.Pertusa were higher than the control group, indicating that the growth was promoted.Meanwhile, the contents of chlorophyll a increased, and carbon and nitrogen stable isotopes were enriched.However, at the high WAF concentrations (5.72 mg/L and 7.17 mg/L), the algal growth was inhibited, with the lower growth rates but higher concentrations of chlorophyll a than those in control group.In addition, compared to the control group, U.Pertusa showed the depletion in δ15N and δ13C at the high WAF concentrations.Overall, the carbon and nitrogen stable isotopes were more sensitive to the WAF stress than chlorophyll a for U.Pertusa.The present study indicated that δ15N and δ13C of U.Pertusa were the promising proxies to evaluate the toxicity of oil spill in marine environment.