Dissertation > Agricultural Sciences > Aquaculture, fisheries > Aquatic basic science > Aquatic Biology > Aquatic Botany

A Study on the Effects of Environmental Factors on Growth, Living Conditions and Uptake Rates of Enteromorpha Prolifera

Author CongShanShan
Tutor GongQingLi
School Ocean University of China
Course Aquaculture
Keywords Environmental Factors Enteromorpha Grow Survival of the state Nitrate Absorption rate
CLC S917.3
Type Master's thesis
Year 2011
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This paper studies the temperature, salinity, light intensity and nutrient concentrations and other four kinds of environmental factors on the growth of green tide Enteromorpha biological, survival status changes and the impact of nutrient absorption capacity, as discussed by the Enteromorpha floating submerged state to state provide the basis for theoretical research. Temperature experimental set 10.0,15.0,20.0,22.5,25.0,27.5 and 30.0 ℃, etc. The results show that Enteromorpha at 10-30 ℃ can maintain more than 20% between the relative growth rate, where the optimum temperature is 25 ℃, relative growth rate of 29.57%; when the temperature is greater than 20 ℃, Enteromorpha from submerged state induced into a floating state, and with the temperature-induced shortened; temperature on chlorophyll a, b and tissue carbon and nitrogen content of element content no significant effect. Salinity experiment set 0,5,10,15,20,25,30 other seven salinity gradients. Experimental results show that the growth of Enteromorpha optimal salinity of 15 -2 5; when the salinity of 5 -2 5 时 Enteromorpha survival status changes; salinity Enteromorpha is 0:00 chlorophyll a / b levels significantly lower than other salinity values ??were 0.399mg g -1 , 0.238mg g -1 , and chlorophyll maximum in salinity of 30, the time of chlorophyll a and chlorophyll b content was 1.547 mg g -1 , 0.793 mg g -1 ; salinity on carbon and nitrogen content in Enteromorpha organization had no significant effect. Light experiment set 20,40,80,160,320,400 μmol · m -2 · s -1 , etc. 6 light intensity gradients. Experimental results show that the optimum Enteromorpha light intensity was 160-320μmol · m -2 · s -1 . Enteromorpha chlorophyll a / b content was negatively correlated with the light intensity at 20μmol · m -2 · s -1 when measured at the maximum, then the chlorophyll a / b The contents were 3.15 mg g -1 and 1.79mg g -1 , while the light intensity of 400μmol · m -2 · s -1 when measured at the minimum, then the chlorophyll a / b levels were 1.19 mg g -1 and 0.49mg g -1 . Enteromorpha organization of light intensity on carbon-nitrogen ratio of carbon and nitrogen, and no significant effects. Nutrient experiment set 0μmol · L -1 and 0μmol · L -1 , 50μmol · L -1 and 3.13μmol · L < sup> -1 , 100μmol · L -1 and 6.25μmol · L -1 , 200μmol · L -1 and 12.5 μmol · L -1 , etc. 4 N, P concentration. The experimental results show that with the N, P concentration, Enteromorpha relative growth rate was significantly increased. Gradient established in this experiment, the highest chlorophyll content in N, P concentrations were 100μmol · L -1 and 6.25μmol · L -1 time, we can see When the N, P concentrations were 200μmol · L -1 and 12.5μmol · L -1 , although the relative growth rate Enteromorpha greater than N, P concentration of 100μmol · L -1 and 6.25μmol · L -1 time, but the chlorophyll content was significantly less than 100μmol · L -1 and 6.25μmol · L < sup> -1 time. NR activity with N, P increases with the increasing concentration. Environmental factors on Enteromorpha nitrate absorption capacity has a significant influence. Enteromorpha different temperatures on nitrate uptake rate than before 6h 12h and 24h; 20 ℃ lower rate of absorption of each time period maximum. Salinity and Enteromorpha absorption rate is positively correlated. Enteromorpha absorption rate is the largest light intensity of 160μmol · m -2 · s -1 when in low light, Enteromorpha on nitrate uptake rate than low. Enteromorpha on nitrate uptake rate increased with the increase of nutrient concentrations increased significantly. In N, P concentration of 200μmol · L -1 and 12.5μmol · L -1 when Enteromorpha for maximum nitrate uptake rate for 8.29μmol · g -1 · h -1 . It can be seen, for the wide temperature Enteromorpha wide salt type of algae, but also to adapt to a larger range of light, which is widely distributed in nature Enteromorpha provides the foundation. Enteromorpha has a high nutritional absorption capacity, can rapidly absorb the nutrients in the water column to achieve their own growth and material accumulation. In addition, at high temperatures Enteromorpha, low salinity conditions, easily submerged by the state into a floating state, and Enteromorpha floating state growth rate of more than submerged state. This is also Enteromorpha in appropriate conditions can form a green tide outbreaks ecological reasons.

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