Nursery‐propagated plants from seed: a novel tool to improve the effectiveness and sustainability of seagrass restoration

Abstract

Summary1. Seagrasses and the valuable ecosystem services they provide are threatened world-wide by impacts of human activity. Numerous revegetation efforts have attempted to restore seagrasses. Most restoration programmes use plants collected from the field because of limited seed availability, low seedling survival and difficulty in culturing plants. However, this practice risks damage to donor populations and has the potential to reduce genetic diversity, which may counteract the desired effects of restoration. 2. A novel aquaculture system for producing plants (mother plants and cuttings) from a limited number of seeds was tested using Cymodocea nodosa as model species. The ability of transplanted cuttings to survive and grow in the natural habitat was also evaluated. 3. Seed germination was high (48%) compared with field conditions, and most seedlings produced mother plants with up to 7Á8 m of rhizome and 300 shoots within 4 years in culture. All cuttings from mother plants regenerated new plants. Up to 100 transplants were produced from two seeds, and most (85%) of them survived and initiated the colonization of substrate, 1 year after planting. 4. Synthesis and applications. This study provides a robust protocol that can reduce plant and/or seed collection pressure on donor populations and produce a high number of transplants which show lower mortality rates during the early transplantation phases. This method can also help to preserve genetic diversity in restored populations, which should be one of the major goals of ecological restoration. This novel tool can be applied to other seagrass species with low or unpredictable reproductive success, therefore the development of nurseries should be incorporated in future restoration programmes. This is currently the only sustainable methodology to produce material for transplanting programmes for protected species.

Effects of Sediment Fertilization and Burial on Cymodocea nodosa Transplants; Implications for Seagrass Restoration Under a Changing Climate

“…Sea surface water temperature varied from 12°C in winter to 27°C in summer and salinity ranged from 37.5 to 38. In June 2010, apical rhizome fragments of C. nodosa (8 cm in length, with two shoots) were excised from nursery grown plants (Balestri & Lardicci ) and transplanted in two sites, hundreds of meters apart, at similar depth (0.20–0.30 m). In each site, fragments (16) were planted at randomly chosen places several meters apart using galvanized iron staples that were removed four months after planting.…”

“…Specifically, we examined the performance and biomass allocation of Cymodocea nodosa (Ucria) Ascherson transplants either subjected to the application of fertilizer to sediments or left at ambient nutrient availability, and exposed to two burial regimes over their second growing season. This small relatively fast‐growing species was selected as a model because of growing interest in restoring damaged meadows (Zarranz et al ; Balestri & Lardicci ). As environmental conditions may vary within a meadow (Balestri et al ; Balestri ), the experiment was conducted in two sites of a north‐western Mediterranean meadow.…”

Assessing Posidonia oceanica Seedling Substrate Preference: An Experimental Determination of Seedling Anchorage Success in Rocky vs. Sandy Substrates

“…The so-called donor bed-independent methods address these requirements through the use of seeds and seedlings [ 8 – 10 ], nursery-propagated plants from seeds [ 11 ], beach-cast vegetative fragments [ 12 ] or the facilitated recruitment of sexual propagules released from adjacent beds through specifically deployed suitable substrates [ 13 – 14 ]. Methods based on the use of sexual propagules also ensure the maintenance of population genetic variability [ 15 ] and should be recommended [ 16 – 17 ].…”

Biotic resistance and vegetative propagule pressure co-regulate the invasion success of a marine clonal macrophyte

“…We conducted two separate mesocosm experiments in an outdoor aquaculture system set up on a coastal dune area at the INVE Aquaculture Research Center of Rosignano Solvay (Italy), and equipped following a protocol established for successfully growing marine plants 50 . The first experiment examined the main and interactive effects of propagule pressure and native species presence on the colonization success (establishment and spread) of the non-native invasive C .…”