The Effect Of Petroleum Hydrocarbon And Nutrients On Phytoplankton And Bacteria In The Jiaozhou Bay

In the dissertation, The effect of petroleum hydrocarbon and nutrients on phytoplankton and bacteria in the Jiaozhou Bay is studied.⒈The petroleum hydrocarbon concentrations and distribution features in Jiaozhou Bay from 1997 to 2004 are analyzed and discussed.⑴The mean concentration of petroleum hydrocarbon is 44.56μg/L,varying from 0.03 to 430.00μg/L in Jiaozhou Bay and in most of the survey sataion. The petroleum hydrocarbon concentrations are higher in the east and northeast of the Bay.⑵The seasonal changes in petroleum hydrocarbon in Jiaozhou Bay indicate that among the three seasons, the average concentration of petroleum hydrocarbon in August is the highest,next is in May, and the lowest is in October.⑶The relationship between the petroleum hydrocarbon concentration and the environmental factors shows that there exists a certain positive correlation between the petroleum hydrocarbon concentration and the dissolved inorganic nitrogen as well as phosphate, suggesting that they might come from a similar source.⒉Petroleum hydrocarbon and nutrients are added into the cultivation,the four phytoplanktons are cultivated. The effects of petroleum hydrocarbon on the uptake of phosphate and nitrogeon by phytoplankton are studied in this paper.⑴Within the first 30 minutes, all the four phytoplanktons have a significant uptake for the two nutrients,and after that the uptake decrease.⑵T he uptake of nutrients by Skeletonema costatum and Heterosigma akashiwo decrease when adding petroleum hydrocarbon;The negative effect of uptake by them weaken at first,and then strengthen with petroleum hydrocarbon increase.When the concentration of petroleum hydrocarbon is low,it improves the uptake of nutrients by the Alexandrium miutum and Scrippsieua trochoidea.As the concentration of petroleum hydrocarbon increases,the positive effect at first strengthen and then wheaken.⑶When the concentration of petroleum hydrocarbon is 8 mg/L,the four algaes are all damaged more or less.⒊Petroleum hydrocarbon and nutrients are added into the cultivation,the three phytoplanktons called Skeletonema costatum,Heterosigma akashiwo and ScrippsieUa trochoidea are cultivated in the lab. The effects of nutrients on the uptake of petroleum hydrocarbon by phytoplankton are studied.⑴Within the first 12 hours,when the nutrients are added according to the redfield ratio, the uptake by the three phytoplanktons are all the best;When adding according to other ratios,the uptake of petroleum hydrocarbon by phytoplankton in the 12 hours is the most when it is inhibited by lack of N,next is P,and the least is Si(only for Skeletonema costatum).Under the same nutrient conditions, the Skeletonema costatum has a higher uptake of petroleum hydrocarbon.⑵In the first 12 hours,the concentration of petroleum hydrocarbon is nearly reduced for the uptake by phytoplankton.After 12 hours,the concentration of petroleum hydrocarbon begin to increase,because the phytoplankton release the petroleum hydrocarbon which it uptake into or onto its cell.⒋Petroleum hydrocarbon and nutrients are added into the cultivation ,bacteria is cultivated regularly,the concentration of Petroleum hydrocarbon and the density of bacteria are measured. The effects of nutrients on the degradation of petroleum hydrocarbon by bacteria are analyzed.⑴At first,the concentration of petroleum hydrocarbon decreases rapidly,and then it is almost unchangeable.⑵When both N and P exist,the degradation of petroleum hydrocarbon by bacteria is the most;when it is lack of N or P,the degradation reduce obviously.The concentration of petroleum hydrocarbon decreases with the density of bacteria increases.