Restoring Eelgrass (Zostera marina L.) Habitats Using a Simple and Effective Transplanting Technique

Abstract

Eelgrass beds in coastal waters of China have declined substantially over the past 30 years. In this study, a simple new transplanting technique was developed for eelgrass (Zostera marina L.) restoration. To assist in anchoring single shoots, several rhizomes of rooted shoots were bound to a small elongate stone (50–150 g) with biodegradable thread (cotton or hemp), and then the bound packet was buried at an angle in the sediments at a depth of 2–4 cm. This stone anchoring method was used to transplant eelgrass in early November 2009 and late May 2010 in Huiquan Bay, Qingdao. The method led to high success. Three month survivorship of the transplanted shoots at the two transplant sites was >95%. From April 20 to November 19, 2012, the following characteristics of the 2009 and 2010 transplanted eelgrass beds were monitored: morphological changes, shoot density, shoot height, leaf biomass, and sediment particle size. Results showed that the sexual reproduction period of the planted eelgrass was from April to August, and vegetative reproduction reached its peak in autumn. Maximum shoot height and biomass were observed in June and July. After becoming established, the transplanted eelgrass beds were statistically equal to natural eelgrass beds nearby in terms of shoot height, biomass, and seasonal variations. This indicates that the transplant technique is effective for eelgrass restoration in coastal waters.

Prolonged buoyancy and viability of Zostera muelleri Irmisch ex Asch. vegetative fragments indicate a strong dispersal potential

“…However in other Zostera species, survivorship subsequent to transplanting has been shown to be low with Thomson et al (2014) reporting 100% mortality of Z. nigricaulis fragments within 100 days. While artificial transplanting techniques have had greater success for Z. marina (L.) with 95% of transplants surviving for more than 90 days (Zhou et al 2014) and 68% survival following 243 days (Kenworthy & Fonseca 1992), these varied findings raise the question as to how effective vegetative fragments of Z. muelleri are at developing new populations?…”

“…In this role, seagrasses alter water flows and increase sedimentation, providing firm substrata for further colonisation by macroalgae and invertebrates (Bos et al 2007). Other notable benefits include important nutrient cycling services, provision of critical nursery habitat for economically significant fish and prawn species, and protection from predators for many marine invertebrates (Waycott et al 2009;Zhou et al 2014). In Z. muelleri, anchorage to the sediment is achieved by the development of herbaceous, laterally compressed rhizomes.…”

Temporal pattern in biometrics and nutrient stoichiometry of the intertidal seagrass Zostera japonica and its adaptation to air exposure in a temperate marine lagoon (China): Implications for restoration and management

“…1), also known as Moon Lake, is a shallow marine lagoon that is located in Rongcheng (Weihai), Shandong, at the easternmost part of Jiaodong Peninsula (Zhou et al, 2014a;Zhang et al, 2014). Swan Lake covers an area of 4.8 km 2 and has an average water depth <1.5 m. The lagoon has an average tide range ca.…”

“…The seagrass bed covers an extensive area in Swan Lake. The dominant seagrass species are Z. marina L. (Zhou et al, 2014a) and Z. japonica. The lagoon is rich in biological resources, such as sea cucumbers (Liu et al, 2013), shellfish, and fish.…”

“…Our recent research programme is to understand and restore the degraded seagrass beds in temperate China, and our previous work has shown that seagrass beds are also an important coastal ecosystem in northern China (e.g. Liu et al, 2013;Zhou et al, 2014a), and we have developed several new techniques for seagrass restoration, mainly on the common species Z. marina (e.g. Zhou et al, 2014b).…”