Effect of silt and clay percentage in sediment on the survival and growth of eelgrass Zostera marina: Transplantation experiment in Swan Lake on the eastern coast of Shandong Peninsula, China

• We investigate the effect of percent silt and clay in the sediment on Z. marina.
• High-silted sediments could promote establishment of eelgrass transplants.
• The survival rate of Z. marina transplants were 100%.
• No negative effects of lower silt sediments on Z. marina transplants are found.
• The most suitable weight percentage of silt and clay in sediment may be 75%.

This study tested the responses of eelgrass Zosteramarina transplants to changes in the silt and clay content of sediments. A transplantation experiment using the staple method was conducted in Swan Lake on the eastern coast of Shandong Peninsula, China. We subjected Z. marina to different weight percentages of silt and clay in sediments (0%, 25%, 38%, 50%, 75%, and 100%) for 120 days and then measured plant response in terms of survivorship, growth rate, individual shoot weight and productivity. Natural sediments (38% silt and clay content) from the experimental site were used as reference sediment. The survival rate of Z. marina transplants was 100%. Aboveground absolute growth rate, shoot weight, and productivity of Z. marina transplants grown on different sediment types varied significantly with maximum values recorded at 75% silt and clay content and the minimum value in reference sediment. However, the rhizome elongation rate was not significantly affected by the silt and clay content of the sediment. The results indicated that sediments with high silt and clay content could promote successful eelgrass transplantation. However, no negative responses were found on sediments with low silt and clay content. The sediment with 75% silt and clay content may be the most suitable for the growth and establishment of Z. marina transplants.