Effects of different current velocities on survival,growth and photosynthetic pigment contents of Zostera marina transplants

Zostera marina transplantation was conducted using the staple method in Swan Lake,a typical lagoon in Rongcheng bay of Shandong Peninsula,China.To determine the suitable current velocity range for Z.marina transplants,survival,growth and photosynthetic pigment contents of Z.marina transplants were examined under different current velocities (6.5,8.2,11.8 and 24.6 cm/s).After 90 days transplantation,survival rate of Z.marina transplants were up to 100%.Under 6.5 to 8.2 cm/s current velocities,the morphological parameters,mass and productivity of Z.marina transplants above ground tissues were significantly higher than those of transplants under 11.8 to 24.6 cm/s current velocities.However these parameters of below ground tissues of Z.marina transplants reached to the minimum in 6.5 cm/s.The photosynthetic pigment contents of all transplants showed the same trends and reached the maximum under 24.6 cm/s current velocity,which were 1.2~1.3 folds higher than other treatments.No significant differences were detected among treatments from 6.5 to 11.8 cm/s.Comprehensive analysis suggests that Z.marina transplants using the staple method can survive at least in the current velocity range from 6.5 to 24.6 cm/s,and the suitable current velocity range for the transplants is from 8 to 10 cm/s.