In this paper,the history,main events and present status of red tide（HAB,harmful algal blooms） along China coast in recent years were reviewed and presented.It showed that the HAB’s frequency and scale,number of HA...In this paper,the history,main events and present status of red tide（HAB,harmful algal blooms） along China coast in recent years were reviewed and presented.It showed that the HAB’s frequency and scale,number of HAB species,percentage of toxic HAB events and the degree of damages to marine environment and economy have sharply increased in China since 1960’s.Eutrophication was key factor for high occurrence of red tide.In this paper,main causes of frequent HAB occurrence along China coast was discussed.Many factors might influence the occurrence of red tide,which included weather,climate,coastal current,tidal current,water temperature,salinity,hydrodynamic and nutrient conditions,trace metals and the variation of biological environment.Numerous evidences from all over the world revealed the linkage between the increases in nutrient loading and the occurrences of high biomass blooms.Eutrophication was one of the important causes that involved in high occurrence of HAB.The main sources of nutrients potentially stimulating HABs included terrestrial runoff,aquaculture self-pollution,atmospheric deposition,sea projects and other pollution events in the ocean.Studies showed that the input from land contaminations and the self-pollution of marine aquaculture accelerated eutrophication in coastal waters and were also important impact factors on red tide.Researches suggested that nutrient composition could affect the species composition of phytoplankton as well as the development of some HABs.The changes in nutrient supply ratios,primarily N∶P,often resulted in shifts in red tide species composition.The correlation between cysts and formation of HAB was discussed from the viewpoint of transformation of cyst and vegetative cell,the effects of trace elements and other organic substances on the occurrence of HAB were presented also.It indicated that the nutrient control could be an effective way to reduce the risk of red tide occurrence.Seaweed would play an important role for decreasing marine eutrophication.Among the different methods of red tide controlling studied,seaweed biomass has received much attention due to the cost saving,low sensitivity to environmental and impurity factors,the possible contaminant recovery from the biomaterial and its elevated adsorption capacity.Cultivated seaweeds have very high rates of productivity higher than that of seaweed in its natural habits and grow well in water bodies with higher nitrogen and other nutrients.Seaweeds are able to absorb large quantities of nitrogen,phosphorus and carbon dioxide,produce large quantities of oxygen,and have excellent effect on decreasing eutrophication.Large amounts of C,N and P are accumulated into seaweed tissues as they accumulate considerable biomass over a period of months or years depending on the cultivation season.When seaweeds are harvested,nutrients are removed from the sea area.An investigation was carried out for inorganic nitrogen and inorganic phosphorus concentration at Lusi Coast,Qidong County,Jiangsu Province in China,where there were about 270 hm2 for Porphyra yezoensis cultivation with eutrophic seawater in recent years.While during Porphyra yezoensis cultivation,from Sep 2003 to May 2004,the concentration of ammonium nitrogen declined form 0.511-0.778 mg·L-1 to 0.006-0.057 mg·L-1,nitrite nitrogen concentration declined from 0.010-0.040 mg·L-1 to 0.001-0.009 mg·L-1,and nitrate nitrogen concentration declined from 0.466-0.549 mg·L-1 to 0.286-0.0568 mg·L-1,the average concentration of inorganic phosphorus declined from 0.024 mg·L-1 to 0.019 mg·L-1. Furthermore,during five hours,the concentration of ammonium nitrogen in the seawater declined form 220.88 μmol·L-1 to 8.59 μmol·L-1 by cultivated Gracilaria lemanaiformis,and the concentration of ammonium nitrogen declined form 213.84 μmol·L-1 to zero by cultivated Enteromorpha clathrata.Other bioremediation mechanisms of seaweed inhibiting the red tide microalgae such as nutrients competition and allelopathic effects were also discussed.展开更多
文摘2006年8～9月,在浙江象山港花鲈（Lateolabrax japonicus）养殖网箱中吊养真江蓠（Gracilaria verrucosa）对网箱养殖造成的水体富营养化进行生态修复研究。通过45d内的平面监测、定点跟踪监测和断面监测,结果表明：该网箱养殖区水体呈严重富营养化状态,营养状态指数（E）为32.00,其营养盐分布由高浓度的中心区向周围150m非养殖水域扩散;真江蓠对养殖区的富营养化海水具有较好的修复效果：江蓠生态修复区及其相邻网箱中水体PO4-P、NO2-N、NH4-N和NO3-N含量显著低于非修复区（P〈0.01）,修复区海水PO4-P、NO2-N、NH4-N和NO3-N浓度比非修复区分别降低22%～58%、24%～48%、22%～61%和24%～47%。养殖真江蓠45d后,修复区水体DO浓度和透明度显著高于非修复区（P〈0.05）,DO平均提高28%,透明度平均提高30%;而修复区水体Chl-a浓度显著低于非修复区（P〈0.05）,平均降低49%。通过建立基于N平衡的鱼藻生态养殖模式,每收获1kg花鲈至少需要匹配江蓠4.7 kg wetwt才可实现对鱼类排放N的完全吸收。因此网箱内栽培江蓠的混合生态养殖模式,可平衡因经济动物养殖所带来的额外营养负荷,有利于实现动物养殖环境的自我修复。
文摘In this paper,the history,main events and present status of red tide（HAB,harmful algal blooms） along China coast in recent years were reviewed and presented.It showed that the HAB’s frequency and scale,number of HAB species,percentage of toxic HAB events and the degree of damages to marine environment and economy have sharply increased in China since 1960’s.Eutrophication was key factor for high occurrence of red tide.In this paper,main causes of frequent HAB occurrence along China coast was discussed.Many factors might influence the occurrence of red tide,which included weather,climate,coastal current,tidal current,water temperature,salinity,hydrodynamic and nutrient conditions,trace metals and the variation of biological environment.Numerous evidences from all over the world revealed the linkage between the increases in nutrient loading and the occurrences of high biomass blooms.Eutrophication was one of the important causes that involved in high occurrence of HAB.The main sources of nutrients potentially stimulating HABs included terrestrial runoff,aquaculture self-pollution,atmospheric deposition,sea projects and other pollution events in the ocean.Studies showed that the input from land contaminations and the self-pollution of marine aquaculture accelerated eutrophication in coastal waters and were also important impact factors on red tide.Researches suggested that nutrient composition could affect the species composition of phytoplankton as well as the development of some HABs.The changes in nutrient supply ratios,primarily N∶P,often resulted in shifts in red tide species composition.The correlation between cysts and formation of HAB was discussed from the viewpoint of transformation of cyst and vegetative cell,the effects of trace elements and other organic substances on the occurrence of HAB were presented also.It indicated that the nutrient control could be an effective way to reduce the risk of red tide occurrence.Seaweed would play an important role for decreasing marine eutrophication.Among the different methods of red tide controlling studied,seaweed biomass has received much attention due to the cost saving,low sensitivity to environmental and impurity factors,the possible contaminant recovery from the biomaterial and its elevated adsorption capacity.Cultivated seaweeds have very high rates of productivity higher than that of seaweed in its natural habits and grow well in water bodies with higher nitrogen and other nutrients.Seaweeds are able to absorb large quantities of nitrogen,phosphorus and carbon dioxide,produce large quantities of oxygen,and have excellent effect on decreasing eutrophication.Large amounts of C,N and P are accumulated into seaweed tissues as they accumulate considerable biomass over a period of months or years depending on the cultivation season.When seaweeds are harvested,nutrients are removed from the sea area.An investigation was carried out for inorganic nitrogen and inorganic phosphorus concentration at Lusi Coast,Qidong County,Jiangsu Province in China,where there were about 270 hm2 for Porphyra yezoensis cultivation with eutrophic seawater in recent years.While during Porphyra yezoensis cultivation,from Sep 2003 to May 2004,the concentration of ammonium nitrogen declined form 0.511-0.778 mg·L-1 to 0.006-0.057 mg·L-1,nitrite nitrogen concentration declined from 0.010-0.040 mg·L-1 to 0.001-0.009 mg·L-1,and nitrate nitrogen concentration declined from 0.466-0.549 mg·L-1 to 0.286-0.0568 mg·L-1,the average concentration of inorganic phosphorus declined from 0.024 mg·L-1 to 0.019 mg·L-1. Furthermore,during five hours,the concentration of ammonium nitrogen in the seawater declined form 220.88 μmol·L-1 to 8.59 μmol·L-1 by cultivated Gracilaria lemanaiformis,and the concentration of ammonium nitrogen declined form 213.84 μmol·L-1 to zero by cultivated Enteromorpha clathrata.Other bioremediation mechanisms of seaweed inhibiting the red tide microalgae such as nutrients competition and allelopathic effects were also discussed.
