Assessment of the establishment success of eelgrass Zostera marina (Alismatales: Zosteraceae) from seeds in a cost-effective seed protection method: implications for large-scale restoration

Abstract

Abstract We describe a protective bag method for planting seeds of eelgrass Zostera marina and have evaluated the cost effectiveness of the method for potential use in large-scale restoration projects. A 90-day laboratory experiment was conducted to determine the effect of protective bags on seed viability. Successful establishment of new patches from seeds in the protective bags was assessed through a seed-sowing field experiment over 11 months. The viability of Z. marina seeds was not significantly affected by the use of protective bags. Retention rate of Z. marina seeds in the protective bags ranged from 64 to 98%, with an average of 85% after 5 months following distribution. The seedling establishment rate of Z. marina ranged from 11 to 44%, with an average of 24% after 6 months following distribution. New patches from the planted seeds were fully developed 11 months after planting with a maximum shoot density of 350 shoots m-2. The cost of planting in 1 ha of sea bed with Z. marina seeds was $14,820, and the average cost per Z. marina seed was $0.03. The protective bag method is an efficient and cost-effective restoration technique, and is potentially useful in facilitating large-scale restoration projects.