| This experiment takes the culture pond of the sea cucumber as the research object,The effects of three time allocation methods of water raising machine on the regulation and control of cultured ponds were analyzed and compared.A pond where the machine works for 6 hours a day,a pond where the machine works for 12 hours a day,and a pond where the machine works for 18 hours a day.In this experiment,the water temperature,salinity,dissolved oxygen,active phosphate,nitrite,nitrate,ammonia nitrogen,total nitrogen and total phosphorus of the ponds cultured in imitation of the sea cucumber were selected as the monitoring indexes,as well as the quantity of heterotrophic bacteria and vibrio in the water and bottom mud,The annual monitoring of the three kinds of artificial culture ponds was carried out.The following results are obtained:(1)During this study,The range of water quality changes in the three allocation methods for the cultured ponds of pseudoginseng is as follows:Water temperature change range:2.15-32.40℃,the salinity range:24.52-35.48‰,dissolved oxygen range 4.85-10.85 mg/L,active phosphate content range:0.004-0.084 mg/L,nitrite content range:0.003-0.016 mg/L,nitrate content range:0.004-0.170 mg/L,ammonia nitrogen content range:0.011-0.093 mg/L,total nitrogen variation range as follows:0.426-2.352 mg/L,total phosphorus range as follows:0.036-0.165 mg/L.There was no difference in water temperature and salinity between the three configurations.The annual mean concentration of dissolved oxygen content was the highest in the 18 h configuration,followed by the 12 h configuration and the lowest in the 6 h configuration.The ponds with an annual concentration of active phosphate of 18 h had the highest concentration,followed by those with a concentration of 12 h,and the lowest concentration of active phosphate of 6 h had the largest difference in August,with no significant difference in other months(P>0.05).The annual change of nitrite was as follows:except for December,the ponds configured with 18 h were significantly higher than the other two kinds of ponds in other months(P<0.05).The annual change of nitrate was as follows:the 18 h configuration of the pond was slightly higher than the other two ponds on September 30 and December 4,with a significant difference(P<0.05);the nitrate concentration difference in the other three configuration of the pond was not significant(P>0.05).The annual change of ammonia nitrogen was as follows:except that the pond configured with 12 h was slightly higher than the other two kinds of ponds on September 30,all other months were lower than the other two kinds of ponds.There was a significant difference between the configured pond and the other two ponds(P<0.05).The annual change of total nitrogen is as follows:the 12 h configured ponds are at a high level throughout the year;the 18 h configured ponds are higher than the 6 h configured ponds from march to June,and lower than the 6 h configured ponds from August to December.Under the three configurations,the total nitrogen concentration in the pond had a significant difference in September(P<0.05),while the difference in other months was not significant(P>0.05).The average annual concentration of total phosphorus was the highest in 12 h,followed by 18 h,and the lowest in 6 h.In August,the total phosphorus concentration in the 18 h pond was significantly higher than the other two ponds(P<0.05).(2)During the experiment,the annual change of the number of heterotrophic bacteria in water in the three kinds of water raising machine was 1.43×10~5-1.36×10~6 cell/mL.The change trend of the number of heterotrophic bacteria in water is basically the same with time,are the trend of first rising and then falling.The mean value of heterotrophic bacteria quantity in water was the highest at 12 h and the lowest at 6 h.However,there was no significant difference in the mean number of heterotrophic bacteria(P>0.05).The quantity of heterotrophic bacteria in the pond water of the three kinds of water raising machines is lower at the inlet and higher at the middle and outlet.There is a significant difference between the inlet and the other two positions in August(P<0.05),but no significant difference among positions in other months(P>0.05).The variation range of heterotrophic bacteria in the mud under the three configurations was 5.11×10~5-1.05×10~7cell/g.The number of heterotrophic bacteria in the mud showed a basically consistent trend with time,which increased first and then decreased.The lowest value of heterotrophic bacteria in the mud of Apostichopus japonicus pond was at the water inlet on March 5,and the highest value was at the middle position on August7.The mean quantity of heterotrophic bacteria in the mud was the highest in 18 h and the lowest in 6 h,but the difference between the mean quantity of heterotrophic bacteria was not significant(P>0.05).The amount of heterotrophic bacteria in the pond mud of the three configurations was lower at the inlet,higher at the middle and outlet,and there was no significant difference in the amount of heterotrophic bacteria in the mud between the three configurations(P>0.05).The quantity of heterotrophic bacteria in water and mud was lower in spring and higher in summer,autumn and winter.(3)During this test,the annual change of vibrio quantity in water in the three configurations of the water raising machine was:38-1752 cfu/mL,The variation trend of vibrio in water was basically the same,which was first increased and then decreased.The lowest value of vibrio in the water of ginseng pool was at the water outlet on March 5,and the highest value was at the water inlet in August,the mean value of vibrio quantity in water was the highest at 18 h and the lowest at 12,but the difference between the mean values of vibrio quantity was not significant(P>0.05).Under the three configurations,the peripheral changes of vibrio in mud are as follows,0-11357 cfu/g.The change trend of vibrio in mud with time is basically the same,which increases first and then decreases.Under the three configurations,the quantity of vibrio was the lowest in the12 h configuration and the highest in the 6 h configuration.There was no significant difference in the quantity of vibrio in mud among the three configurations(P>0.05).The quantity of vibrio in water and mud was lower in spring and winter and higher in summer and autumn. |
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