Growth of Enteromorpha Prolifera Under Different Uutrient Conditions

A large scale of Enteromopha prolifera tide(in green)occurred in the coastal area of Qingdao in June 2008.The samples are taken in the area to study the growth rate of Enteromorpha prolifera under different nutrient conditions in the laboratory.As the results show,the daily average relative growth rate of Enteromorpha prolifera is 3.85%/d for the control sample group without any nutrients added.The growth rate of the group with 10 μmol/L concentration of nitrogen(N)added is 6.31%/d and the rate of the group with 50 μmol/L concentration of N added is 6.32%/d.The growth rate of the group with 1 μmol/L phosphorus(P)added becomes 5.79%/d,lower than any of the N-added groups.There is less difference between the rate of the experimental group with both 20 μmol/L of N and 1 μmol/L of P added and the rate of the group with only N added.If N,P,and other tracers are all added into the nutrients solution,the growth rate becomes 6.84%/d,the highest among those groups.The rate can be fruther high if the nutrients solution is renewed everyday and it is 7.75%/d The maximum rate appears on the third day.It can reach as high as 27.57%/d under the optimum conditions.It is shown by the experiment that enteromorpha prolifera need much of N,and the tracers such as Fe,Mn etc.help a lot for its growth.