海水氮浓度和盐度对孔石莼(Ulva pertusa)生物量和碳氮含量的耦合影响

Coupling effects of nitrogen and salinity in seawater on biomass,carbon and nitrogen contents of Ulva pertusa

全球气候变化和人类活动已经对近岸海域海水氮营养盐和盐度产生了显著影响。孔石莼(Ulva pertusa)作为温带近岸海域的优势种,在富营养条件下会爆发性生长,对海洋生态系统造成显著的负面影响。本研究采用室内模拟实验,分析了海水中氮营养盐和盐度对孔石莼的耦合影响。结果表明:海水氮营养盐和盐度对孔石莼的生物量有显著的协同影响,在较高的盐度(40)条件下,孔石莼生物量较高,并且氮营养盐升高会使其生物量降低;孔石莼组织碳(C)含量、氮(N)含量以及碳氮比值(C/N)与氮营养盐浓度无显著相关性,与海水盐度有显著相关性。研究结果可为明确全球气候变化背景下富营养化海域大型海藻爆发的机制和科学管理提供依据。

Global climate change and human activities affect nitrogen nutrient and salinity in coastal waters.Ulva pertusa,a dominant species in the coastal waters of temperate zones,will grow faster under eutrophication conditions,with negative impacts on marine ecosystems.In this study,the coupling effects of nitrogen content and salinity of seawater on U.pertusa were examined in laboratory experiments.The results showed that nitrogen and salinity had significant synergistic effects on the biomass of U.pertusa.Under high salinity(40)condition,U.pertusa showed high biomass,whereas nitrogen enhancement led to lower biomass.C,N concentrations and C/N ratio in U.pertusa tissues did not correlate with seawater N concentration,but correlated with seawater salinity.Our results provide a basis for the mechanism and scientific management of macroalgae blooms in eutrophication water under the background of global climate change.