| Green tide is large Marine algae blooms,caused its biomass accumulation in the intertidal zone and shallow water area of an abnormal ecological phenomenon.The main organisms have the green tide genera(Ulva),hard trichodesmium(Chaetomorpha)and bristles chara(Cladophora)and other large algae.Usually occurs in the estuary,lagoon,bay and city populated coastal waters eutrophication degree is relatively high,such as environment.Human activities caused by offshore nutrients,especially nitrogen(N)and phosphorus(P)content increased,often cause algae outbreak.In the eutrophication of water environment,and the green tide algae under the stimulus of nutrient can be multiplied,and high light energy use efficiency,with strong competitive advantage.Green tide algae breeding way of diversity,including sexual reproduction and asexual reproduction,vegetative propagation,etc.Reproductive ability,in the middle of the life cycle of any shape can develop into mature algae body alone.This article in view of the green tide alga,from green tide algae growth and the change of water quality,prevent adhesion,enteromorpha enteromorpha spores into algal chemical culling and the use of biological research,and in order to green tide algae removal and effective utilization of the development of new methods.??Assessment of bioremediatin abilities of U.flexuosaBased on investigation data obtained from January to December in the enclosed Fengxian bay throughout the 2015,water quality and eutrophication conditions were evaluated on the basis of organic pollution index(A)and eutrophication index(E)and the species composition,biomass as well as bioremediation abilities of benthic algae community were analyzed.The results of water quality indicate that this mariculture area has been in serious eutrophication state.Dissolved inorganic nitrogen(DIN)and dissolved inorganic phosphorus(DIP)complied with the Grade inferior ? and ?,respectively.The annual average values of A and E were 1.88 ±0.21 and 29.95±1.18,respectively.The results also show that the dominant species of green algae is E.flexuosa,accounting for 97.3%.From March to December in 2015,the biomass of U.flexuosa increased by 1497.3 tons.The average N and P contents of algae were 3.50% ± 0.02% and 0.13% ± 0.01% and(4354.90±46.78)kg of N and(161.75±1.74)kg of P could be removed by this seaweed.The population of U.flexuosa has certain bioremediation abilities by assimilating nutrients generated by human aquaculture activities.However,the biomass of U.flexuosa stocked on hand could not completely remove all excess nutrients.Establishing an integrated multi-trophic level system co-cultured with macroalgae showed high bioextraction efficiencies on nutrients and could balance the nutrient produced by marine aquatic animal farming in the enclosed bay.??The influence of coating and paint on algae attachedIn the laboratory,explores the coated with two kinds of coating and a kind of plastic,bamboo,glass paint effect of germination of enteromorpha gametes.The results showed that enteromorpha gametophyte in three kinds of matrix on the germination rate were 0%,inhibitory effect is obvious.Respectively,moreover,in October 2016-March 2017 in jiangsu rudong laver culture zones and medlar island mussels culture zones in zhejiang province,using two kinds of coating and daub a paint of rope,watch the wild algae and fouling organisms in the attachment.Placed on some laver culture zones of daub on two kinds of coating and paint a cable,algae are not attached,mussels in Chinese wolfberry island culture zones of two kinds of coating of fouling organisms to the cable,and over time extended,attachments to continue to increase,apply paint is not found on the cable of algae and other nondestructive biofouling.??Chemical removalPorphyra Porphyra Porphyra cultureculture has important position in China's aquaculture,which is one of the representatives of the aquaculture industry in China,and its scale is second only to the kelp in the algae culture industry.On the world market,Porphyra Porphyra culture in our country has grow dramatically in the late 90 s,and overtake Japan as the world's largest seaweed culture country in 2000.However,Porphyra Green algae on Porphyra culture raft frame became one of the important factors that affect the growth and quality of seaweed in our country.Therefore,how to efficiently remove Porphyra culture raft frame attached green algae has become an important problem.This study taking Jiangsu Porphyra culture zones mainly speciegreen alga-attached green algae,U.flexuosa,as an object,investigated the effects of two kinds of organic acid on the growth and kill effect.The main results were as follows:1.We used attached U.flexuosa green algea for investigation,studied the effects of different time 0.5% Lactic acid on photosynthetic rate.U.flexuosa by liquid oxygen electrode,Chlorophyll extract and chlorophyll fluorescence technology.The results showed that the photosynthetic rate of U.flexuosa decreased to 44 % of the control group with 0.5min 0.5% Lactic acid treatment.With Lactic acid soaking time increased.U.flexuosa are gradually decreasing.After 4min 0.5% Lactic acid treatment,Chla and Chlb respectively reduced to 2.917 mg/L and 2.474 mg/L.0.5 and 1min 0.5% Lactic acid have significant influence on the fluorescence characteristics of the algae.2.We invested the effects of Citric acid with different soaking time on photosynthetic rate.U.flexuosa by liquid oxygen electrode,Chlorophyll extract and chlorophyll fluorescence technology.The results showed that as for the photosynthetic rate of U.flexuosa,we found that after 0.1% Citric acid treated 0.5min,the rate was only 1/4 of control algae,and there was no significant difference from 1.0 to 2.0 min,while the photosynthetic rate of algae of 4.0 min have gone down to 0.004?mol·min-1·g-1.After 0.1% Citric acid treated,the content of Chla and Chlb were both declining,and with time of 0.1% Citric acid treatment increased,Chla and Chlb content decreasing.After 0.1% Citric acid soaked 4min,the content of Chla decreased by 89.5 %,Chlb decreased by 89.7 %,and the whole chlorophyll content decreased by 89.6 %.With 0.1% Citric acid soaked,Fv/Fm had a dramatic decline,and Fv/Fm of E.flexuosa decreased to 2 % of the control group with 1min treatment.while the Fv/Fm of algae of 2 and 4min was undetectable.3.Combined with this two kinds of organic acids,Common to different soaking time of U.flexuosa and seaweed processing.Studied photosynthetic rate U.flexuosa by liquid oxygen electrode,Chlorophyll extract and chlorophyll fluorescence technology.The results showed that Ulva 0.5min under the acid treatment,make its photosynthetic rate dropped to 7.4% of the blank sample quickly and seriously disrupted photosynthesis,increase over time,after the photosynthetic rate at 0.002?mol/min·g;Porphyra is only at the time of processing time is 4.0 min,photosynthetic rate fell slightly,other no obvious difference between the experimental group and the blank group.After soaking solution of Ulva and Porphyra of chlorophyll content were reduced,0.5min processing makes Ulva chlorophyll fell to 38.02% of the blank group,and between 1 to 4min,the content of chlorophyll gradually dropped to near zero point;Porphyra chlorophyll is not sensitive to acid treatment,only in 2.0 and 4.0min group has slightly visible change.By soaking the solubility solution 0.5min can make normal Ulva algae body Fv/Fm value dropped below 0.2,4min group appear even in low of 0.031,basic lose the ability of photosynthesis;And after the solution treatment of seaweed algae body Fv/Fm value and no significant difference,only 4min value fell slightly,to 83.1% of the blank control group.??Effects of three different states of U.prolifera on feeding habit characteristics of Siganus canaliculatusThe study was conducted to evaluate the effects of three different states of U.prolifera on feeding performance of juvenile Siganus canaliculatus and then water qualities were assessed by comparing fed with U.prolifera and artificial diets.To investigate the daily food intake,feeding rhythem and growth characteristics of S.canaliculatus,180 fish were equally cultivated in twelve 50cm×40cm×40cm cages(15 fish per cage and).The fish were divided into four diet groups(three cages of each group)and fed with three different states of U.prolifera(green,yellow-green and yellow,i.e.,treatments)and traditional diet(i.e.,controls)for 120 d,respectively.During the culturing period,water temperature varied from 24°C to 25.5°C,p H was 8.3±0.3,and dissolved oxygen was more than 5.0 mg/L.The results showed that the daily food intake quantity of the group fed with green U.prolifera was significantly higher than the other two groups with yellow-green and yellow seaweeds(P<0.05).The optimal feeding density of green U.prolifera was 3-8 g/ind.There were three apparent feeding peaks at 5:00-7:00,9:00-11:00 and 13:00-15:00.S.canaliculatus had no feeding behavior at night.The average weight and length of each fish increased from 3.83±0.20 g,53.5±2.3cm to 7.63±0.47 g,87.4±0.8cm at the beginning and end of experiment,respectively.Compared with traditional fish diet,feeding with green U.prolifera showed positive advantages for ameliorating water environment.These results indicated that,considering the production of fish and low-cost environmental diets,the advice for using S.canaliculatus to control the booming growth of E.prolifera could realize an important role in the future. |
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