Seagrass restoration using seed ball burial in northern China

As seagrass bed restoration by seeding becomes more common, it is necessary to develop a simple and reliable method to improve the efficiency of seed-based restoration. In this study, we describe a novel method using seed ball burial for eelgrass restoration. Using this method, seeds were wrapped in a wet mud ball, which represented a transplant unit, and the balls were then buried in the sediment. Three experiments (proof of concept study, main study, and large-scale restoration) were conducted to test this method at three degraded sites (Rizhao, Qingdao, and Tangshan) with different environmental conditions. The density of seedlings and seedling shoots was 54 and 110 per m(2), respectively, in Rizhao, a site with coarser sediment and higher temperatures. Seedling survival in Qingdao reached 46.67 +/- 9.46%. Relatively low seedling survival (26.67 +/- 7.03%) in Tangshan was induced by local waves and currents. Seedling survival was also low (ca. 15% in April and 2% in July) at the large-scale restoration site , reflecting a mismatch between the environment at this site and the seed ball restoration method. In conclusion, our study provides evidence of the effectiveness of a novel seagrass seed planting method referred to as seed balls.