Study Of Photosynthetic And Bioremediation Of Large Epiphytic Marinealgae In Mariculture Area

Seaweed as primary producers of important marine ecological system, has the ability of super accumulation of nutrients, by which the eutrophication of waters can be repaired effectively. The study of physiological ecology and bioremediation of marinealgae has an important role in the development and utilization of algae. This paper carried out large epiphytic marinealgae and seasonal changes in photosynthetic carbon sequestration, the repair of aquaculture wastewater from large seaweed under laboratory conditions, and effect of environmental factors on the absorption of nutrients and growth of Codium fragile.1. Seasonal variation of large epiphytic marinealgae in mariculture areaLarge epiphytic marinealgae from marichulture area in Ningde Sanshawan and Lianjiang Luoyuan Bay mariculture area were collected and identified. A total of 18 marinealgae was reported. Rhodophyta has most 11 species, including Grateloupia turutura, Polysiphonia urecolata, Martensia fragilis, Hyphea cervicornis, Ceramium japonicun,, Corallina officinalis, Acanthophora spicifera, Chondrus ocellatus, Gracilaria asiatica., Gracila sp, Lomentaria hakodatensis. Chlorophyta has 6 species, including Cladophora hutchinsiodes, Bryopsis plumose, Enteromorpha prolifera, Ulva pertusa, Chaetomorpha spirclis, Codium fragile. One species?Sargassum horner? was found in Phaeophyta. In different seasons, there is a large difference in the number and size for the same species of algae. Most algae grow well in the spring.2. Study on Photosynthesis of large epiphytic marinealgaeUsing black and white bottle method, we measured photosynthesis of large epiphytic algae in Sanshawan and Luoyuan Bay mariculture area. The results showed that the photosynthesis of Grateloupia turutura and Ulva pertusa were better in the four seasons tested, and the effect of oxygen production and carbon fixation was the best in summer. Comparison of different epiphytic marinealgae absorption rate of PO₄^3--P on the seasonal variation showed that the Ulva pertusa, Grateloupia turutura and Gracilaria asiatica in four seasons on absorption rate of PO4-3-P was higher, Acanthophora spicifera on absorption rate of PO₄^3--P is lower.3. Nutrient absorption and purification of of marine alga in aquaculture wastewaterIn the condition of indoor environment, after cultivation of 6 days, effect on purification of wastewater is obvious in Grateloupia turutura, Cladophora hutchinsiodes, Chaetomorpha spirclis and Codium fragile, and the highest uptake rate of nitrogen and phosphorus was found in the high concentration group. Of four species tested, Grateloupia turutura was the best bioremediation species. Four species of marine algae growed healthly in aquaculture wastewater, maintaining a certain growth rate, but Grateloupia turutura and Codium fragile in the late stage of cultivation appeared "whitening" phenomenon.4. Effects of temperature and salinity on nutrient absorption of Codium fragileThe growth and nutrient absorption of Codium fragile at different temperature and salinity were studied. The results show that the temperature had highly significant impact on the growth of Codium fragile ?P<0.01?, salinity had significant effects on the growth of Codium fragile ?P<0.05?. There were the highest growth rate of SGR in combination with a temperature of 25? and salinity of 20, and the best absorption rate of nutrients in combination with the temperature of 32? and salinity of 30 in Codium fragile.