海州湾海洋牧场人工鱼礁投放对营养盐的影响

为了解海州湾海洋牧场人工鱼礁投放对营养盐的影响,基于2008—2015年间共24个航次水质调查资料,分析了海州湾海洋牧场鱼礁区和对照区活性磷酸盐(PO_4~(3-)-P)、活性硅酸盐(SiO_3~(2-)-Si)和溶解无机氮(DIN)的浓度、组成及营养盐结构的变化.同时,比较了鱼礁区和对照区营养盐的变化,初步分析了人工鱼礁投放量与营养盐的相关性,尝试探索人工鱼礁投放对营养盐浓度与结构的影响.结果表明,鱼礁区和对照区PO_4~(3-)-P、SiO_3~(2-)-Si浓度均呈现出秋季夏季春季的特点,且鱼礁区高于对照区.DIN在鱼礁区和对照区也呈现出同样的季节变化特点,但鱼礁区的变化幅度显著大于对照区.海洋牧场人工鱼礁的投放使鱼礁区PO_4~(3-)-P和DIN浓度增加.受热力学平衡的影响,对照区DIN浓度也出现了增加,而PO_4~(3-)-P受人工鱼礁投放的影响小.鱼礁区和对照区SiO_3~(2-)-Si受人工鱼礁投放影响均不明显.另外,海洋牧场DIN组成也发生了改变,2012年前NO_3~--N为DIN主要组成,之后为NH_4~+-N.营养盐结构分析显示,海州湾海洋牧场营养盐对浮游植物主要表现为磷限制.

Effects of artificial reefs deploymenton nutrients in the marine farming zone of Haizhou Bay

According to the water quality survey data collected during 24 cruises in the reef and control areas from 2008 to 2015, the concentration, composition and seasonal distribution variationsof active phosphate (PO₄^3--P), active silicate (SiO₃^2--Si) and dissolved inorganic nitrogen (DIN) were studied to understand the effects of artificial reefs deployment on nutrients in the marine farming zone of Haizhou Bay.These data were discussed in terms of the nutrient changes in reef and control areas, the relationship between nutrients and delivery volume of artificial reefs, and the nutrient structure changes in the marine ranching area.The seasonal concentration levels of PO₄^3--P and SiO₃^2--Si show that autumn > summer > spring in the reef and control areas, and the amounts of both chemical species in reef area are higher than the control area.Although similar seasonal trends of PO₄^3--P, SiO₃^2--Si and DIN contents are found in both studied areas, the seasonal variation of DIN in the reef area is more significant than the control area.And the results show that the contents of PO₄^3--P and DIN can increase withthe deployment of artificial reefs.Moreover, our data suggest that the level of DIN in the control area can be promoted due to the thermodynamic reactions.In contrast, this promotion in the reef area is not obvious.Additionally, the data also present that the dominant composition of DIN in the marine ranching area has been changed from NO₃^--N to NH₄⁺-N since 2012.The changes of nutrient structure indicate PO₄^3--P is the main limiting factor for the development of phytoplankton in the marine farming zone of Haizhou Bay.