Like other coastal ecosystems, seagrass beds are under severe threat from eutrophication of coastal waters and the progressing use and development of coastal zones in Hainan. According to our recent study in ECOLOC project conducted by Tim Jennerjahn and his team at the Leibniz Centre for Tropical Marine Research (ZMT), 87% of the biomass of the seagrass beds in the study area disappeared in only ten years and their species richness decreased enormously (Thomsen, et al. 2020).
Seagrass restoration is a common tool for ecosystem service enhancement and compensatory mitigation for habitat loss. Since 2018, Hainan Academy of Ocean and Fisheries Sciences led by ECOLOC Chinese coordinator, Daoru Wang, has been transplanting seagrasses in the northeast coast of Hainan, which was previously destroyed by channel expansion and sea reclamation.
Restoration of seagrasses on exposed open coasts poses special challenges, both logistical and environmental. Several seagrass species were used in the transplanting efforts, including Enhalus acoroides, Thalassia hemprichii and Cymodocea rotundata. After tested, Enhalus acoroides and Thalassia hemprichii were chosen as the species for trial. In terms of transplant methods, China’s desert control method – grid of straw squares, inspired the researchers to make a similar version, which consisted of fishing nets and iron plates.
“When the sea bed is fully recovered, the nets and grid will be disassembled and recycled. The recovered seagrasses will emerge in an orderly pattern as they grow. Little by little, vast stretches of seagrass beds will be formed,” Chen Shiquan, a key member on the research team explained.
More reports are published on: http://en.people.cn/n3/2020/0617/c90000-9701287.html (English), or http://www.iziran.net/difanglianbo/20200617_125050.shtml (Chinese)