PROJECT DESCRIPTION
BACKGROUND
Some coastal lagoons of considerable ecological importance in the Mediterranean have been progressively depleted of marine phanerogams – vascular, flowering plants that live fully submerged in coastal marine environments. This decline has led to an impoverishment of the biodiversity of this habitat.
Marine phanerogam vegetation is predominantly composed of seagrass meadows, which play a key role in stabilising the seabed and maintaining water quality. The loss of such vegetation can be attributed to various factors, including changes in water circulation and the accumulation of organic matter. One important side-effect of this habitat degradation is the colonisation by invasive alien plant species.
OBJECTIVES
The LIFE-TRANSFER project aimed to improve the conservation status of the Coastal lagoons habitat in 5 Natura 2000 sites: 3 in Italy (Valli di Comacchio; Sacca di Goro, Po di Goro, Valle Dindona, Foce del Po di Volano; and Delta del Po: tratto terminale e delta Veneto), 1 in Greece (Amvrakikos Gulf – Logarou/Mazoma lagoon) and 1 in Spain (Mar Menor).
The project would follow the process of recolonisation of aquatic plants (phanerogams) by transplanting small sods and rhizomes of species previously present in each area: Zostera marina (eelgrass), Zostera noltii (dwarf eelgrass), Ruppia cirrhosa (spiral ditchgrass) and the seagrass Cymodocea nodosa. The aim was to enhance the natural propagation capacity of these plants through seed production, harvesting and dispersion.
The specific objectives were:
- restoring and consolidating priority Coastal lagoons habitats at 6 sites by transplanting submerged phanerogams, to promote ecosystem self-sustainability (an area of 1 000 m2 was to be transplanted at each coastal lagoons with seagrass species typical of that biogeographic area), by restoring water circulation in one lagoon and removing invasive green algae in another lagoon,
- contributing to achieve a good ecological state of transitional water, in line with the objectives of the EU Water Framework Directive,
- quantifying the value of ecosystem services provided by the coastal lagoon environments and the seagrass meadows,
- training future trainers in the habitat restoration techniques, targeting site managers/professionals not participating in the project to ensure transferability and replicability in other sites.
RESULTS
Building on the successful methodology developed by a previous LIFE project – LIFE SeResto – the LIFE-TRANSFER project implemented a network of small-scale transplants that served as nuclei for natural recolonisation. After 5 years, the process of seagrass recolonisation obtained varying results depending on the lagoons and species, and hence, the extension of the target Coastal lagoon habitat remained the same in the different sites, and did not increase as expected.
- Mar Menor (Spain): Cymodocea nodosa transplants demonstrated an over 80% survival rate with substantial growth as expected, while Ruppia cirrhosa showed approximately a 65% survival. The total newly formed surface by angiosperms of the target habitat was 935 m2 (900 m2 of C. nodosa and 35 m2 of R. cirrhosa).
- Caleri Lagoon in the Delta del Po (Italy): Zoostera noltei has shown exceptional growth, with transplanted sods expanding from 15cm to over 1m in diameter within a single growing season. By 2025, these patches (with a survival rate of the transplanted sods over 50%) have merged to create continuous meadows, transforming the previously bare substrate. In the other Italian Lagoons (Goro-Bassunsin, Barbamarco, Fattibello) transplant was not successful and only small, scattered tufts of angiosperm meadow were present, indicating limited establishment success.
- Logarou Lagoon (Greece): the survival rate of transplanted sods appears dependent on the type of methodology used. With the updated tools designed by the project, the 6-month survival rate ranged from 38% to 46%, whilst the 12-month survival rate ranged from 28% to 46 % during the project lifetime.
In the Barbamarco Lagoon, in addition to seagrass transplant, dredging of a sub-lagoonal channel improved water circulation and prevented anoxic phenomena over about 600 hectares.
Despite the seagrass transplant not being very successful in all sites, it has triggered a cascade of positive effects on water quality improvement for the lagoons of the targeted Natura 2000 sites across Italy, Spain and Greece, as quantified through multiple physio-chemical and biological indicators:
- the Macrophyte Quality Index (MaQI) improved from "Poor" (0.25) to “Moderate" (0.55) in the Caleri lagoon, demonstrating enhanced plant community structure,
- the Benthic Macroinvertebrate Index (M-AMBI) in transplant sites consistently showed higher values compared to control sites, with Caleri and Barbamarco reaching "Good" status,
- the Habitat Fish Bio-Indicator (HFBI) in transplant areas showed increased values (0.35 in Caleri versus 0.21 in control sites), indicating improved habitat quality for a richer fish community.
These combined results demonstrate that the approach of small-scale, strategically placed transplants can effectively initiate large-scale habitat recovery. Through the transplanting of native seagrass species, the project has initiated a process of ecosystem recovery that extends beyond simply restoring vegetation cover.
The main technical improvements of the seagrass transplants are:
- the adaptability of the transplant method to different environmental conditions: in turbid waters, the project developed a specialised tool for planting sods in the highly turbid waters of Logarou Lagoon (Greece), where low visibility makes traditional transplantation methods challenging,
- species-specific approaches: the different success rates and methodologies for various seagrass species (Z. marina, Z. noltei, R. cirrhosa and C. nodosa) were described in detail in a handbook, providing valuable insights on which species work best under specific conditions,
- small-scale, low-impact methodology: a refined technique uses small sods – 15 cm diameter – making transportation easier and reducing impact on donor sites while maintaining effectiveness; for larger species such as Z. marina it was possible to transplant the single rhizomes.
The presence of the invasive alien species Caulerpa prolifera was not eliminated in the Mar Menor site, but the transplant of seagrass proved to be efficient in triggering the recolonisation of the area coping with the invasive species.
LIFE TRANSFER also offered relevant information for the implementation of the Nature Restoration Law.
- Evidence-based restoration techniques: the project provided tested restoration measures for coastal lagoons through seagrass transplantation, as a practical example of restoration measures. The varying success rates between species (e.g. C. nodosa performing better than R. cirrhosa) provide valuable insight for developing species-specific restoration protocols.
- Stakeholder engagement model: the successful involvement of local fishers in restoration activities demonstrates a practical approach to the socio-economic considerations embedded in the Nature Restoration Law (50 local operators trained). This participatory model helps build local ownership of restoration efforts and aligns nature conservation with livelihoods, addressing one of the main concerns about implementation feasibility.
The LIFE TRANSFER project also involved 2 675 students in environmental education activities and developed a replicable methodology for knowledge transfer events targeting site managers and technicians from other Natura 2000 sites (training of 8 trainers). Through this knowledge transfer, the project staff of another LIFE project – LIFE FOR POMORIE LAGOON – adopted the methodology of seagrasses transplant in their coastal lagoon restoration activities.
