“Seagrass ecosystems are shaped by tightly coupled biological and physical processes that determine their persistence, recovery, and response to environmental change”.

Seagrass meadows are among the most productive and valuable coastal ecosystems, yet they have declined dramatically across much of their range due to eutrophication, physical disturbance, altered hydrodynamics, and cascading ecological feedbacks. As a result, restoration has become a central tool in coastal management. However, restoration success remains highly variable, and many efforts fail to establish self-sustaining meadows.

Over the past two decades, my research has focused on why seagrass restoration succeeds in some contexts and fails in others, and on translating mechanistic understanding of ecological and physical processes into practical, scalable restoration strategies. Rather than treating restoration as a planting problem, this work frames restoration as a diagnostic challenge, where success depends on identifying and overcoming site-specific recruitment bottlenecks.

This theme presents applied research on seagrass restoration outcomes and interventions, integrating insights from seed ecology and hydrodynamics-seagrass interactions to provide an evidence-based framework for designing restoration that works with, rather than against, ecosystem processes.

Seagrass restoration is constrained by interacting biological and physical processes operating across spatial and temporal scales. Key questions guiding this research include:

• What mechanisms prevent natural recovery after seagrass loss?
• When are seed-based approaches preferable to transplanting adult shoots?
• How do waves, currents, and sediment dynamics constrain establishment and survival?
• Which feedbacks stabilise restored meadows, and which promote collapse?
• How can restoration methods be adapted to local environmental conditions?

Addressing these questions requires integrating ecology, hydrodynamics, and geomorphology, rather than treating restoration as a purely biological problem.

Restoration can be implemented using seeds, nursery-raised seedlings, or transplantation of adult shoots, and these approaches differ fundamentally in scalability, cost, and vulnerability to site conditions. Seed-based methods offer the greatest potential for large-scale restoration with minimal donor impacts, but success is often limited by bottlenecks acting on early life stages (e.g., seed availability and maturity, dispersal and retention, predation, burial depth, sediment oxygen conditions, and seedling stability under hydrodynamic exposure). Seedling-based approaches can bypass some early constraints through nursery production and controlled establishment, while adult shoot transplants may perform better where recruitment windows are narrow or physical stress is high, at the expense of higher cost and potential donor impacts. My work uses a process-based framework to diagnose which bottlenecks dominate at a site and to match restoration method choice to local ecological and hydrodynamic constraints.

Key publications:

• Infantes et al. (2016) Eelgrass (Zostera marina L.) restoration methods on the west coast of Sweden using seeds. MEPS.
• Eriander et al. (2016) Assessing methods for restoration of eelgrass (Zostera marina L.) in a cold temperate region. JEMBE.
• Infantes & Moksnes (2018) Eelgrass seed harvesting: flowering shoot development and restoration on the Swedish west coast. Aquatic Botany.
• Zenone et al. (2025) Stitching up Posidonia oceanica anchorage scars using beach-cast seeds. Biological Conservation.

Restoration is often evaluated by short-term plant survival and cover, yet the long-term value of restoration depends on whether meadows recover the functions and services that motivate restoration in the first place. These include habitat complexity, biodiversity support, food-web recovery, and key ecosystem processes such as benthic metabolism and carbon cycling. My work quantifies how quickly communities recolonise restored meadows and how ecosystem functioning responds during recovery, providing outcome-based benchmarks that complement establishment-focused metrics.

Key publications:

• Gagnon et al. (2023) Rapid faunal colonisation in restored eelgrass. Restoration Ecology.
• Kindeberg et al. (2024) Structural complexity and benthic metabolism in restored seagrass meadows. Biogeosciences. 
• Castro-Fernández et al. (2025) Fish community structure in restored eelgrass meadows. Aquatic Conservation.

In many systems, seagrass loss triggers coupled physical and ecological feedbacks that prevent natural recovery, including increased turbidity, sediment instability, altered biogeochemistry, and shifts in faunal communities. Hydrodynamic exposure can amplify these processes by increasing sediment resuspension and light limitation, while feedbacks can stabilise degraded states even after initial stressors are reduced.

Restoration therefore often requires breaking negative feedbacks and working within physical limits, rather than simply reintroducing plants. By integrating physical constraints with ecosystem feedbacks, this work helps explain why recovery trajectories diverge among sites, and why some systems exhibit threshold dynamics and regime shifts.

Key publications:

• Adams et al. (2018) Water residence time controls the feedback between seagrass, sediment and light: implications for restoration. Advances in Water Research.
• de Smit et al. (2022) Quantifying the resilience of seagrass to climate change: combining in-situ wave-erosion experiments with data-driven modelling. Limnology and Oceanography.
• Infantes et al. (2022) Seagrass roots strongly reduce cliff erosion rates in sandy sediments. MEPS.
• Moksnes et al. (2018) Local regime shifts prevent natural recovery and restoration of lost eelgrass beds along the Swedish west coast. Estuaries and Coasts.
• Riera et al. (2020) Regime shifts in Zostera marina epifauna: a 21-year comparative study in the Swedish Skagerrak. Marine Pollution Bulletin.

Beyond planting methods, restoration success often depends on modifying local conditions to favour establishment. No single technique resolves restoration failure across all systems. Instead, interventions must be matched to diagnosed bottlenecks.

Evaluated approaches include sediment manipulation and sand capping to improve substrate stability, reduction of hydrodynamic stress to enhance early establishment and survival, nursery-based seed and seedling production to increase propagule availability while minimizing impacts on donor meadows, and adaptive, site-specific planting strategies that align restoration methods with local ecological and physical constraints.

Key publications and applied resources:

• Domínguez et al. (2012) Experimental evaluation of the restoration capacity of a fish-farm impacted area with Posidonia oceanica seedlings. Restoration Ecology.
• van der Heide et al. (2022) Coastal restoration success via emergent trait-mimicry is context dependent. Biological Conservation.
• Temmink et al. (2020) Mimicry of emergent traits amplifies coastal restoration success. Nature Communications.
• Cossa et al. (2025) Restoring Halodule uninervis: evaluating planting methods and biodiversity. Restoration Ecology.
• Sand capping to promote eelgrass restoration (Video-Blog)
• Handbook for eelgrass restoration in Sweden – A guideline (Handbook)
• Seagrass Nursery Network – Kristineberg (Video-Blog)

Restoration outcomes increasingly depend on interacting stressors that affect physiology, sediment processes, and ecological interactions. Beyond classic drivers such as eutrophication and physical disturbance, emerging pressures, including microplastics and microbiome disruption, may erode resilience and alter carbon cycling even when restoration establishes initial plant cover.

This work examines how stressors interact and propagate through microbial pathways and sediment processes, providing mechanistic insight into why restored or recovering meadows may remain vulnerable to collapse.

Key publications (emerging stressors):

• Egea et al. (2026) Successive stressors alter microbiome composition and reduce resilience in the eelgrass Zostera marina. Marine Environmental Research.
• Egea et al. (2026) Microplastics threaten seagrass carbon sinks through microbial changes. Marine Pollution Bulletin.
• Dakos et al. (2025) Carbon storage of seagrass ecosystems may experience tipping points in response to stress: a modeling perspective. Frontiers in Complex Systems.
• Cossa et al. (2024) Hidden cost of pH variability in seagrass beds on marine calcifiers under ocean acidification. Science of the Total Environment.
• Moksnes et al. (2021) Major impacts and societal costs of seagrass loss on sediment carbon and nitrogen stocks. Ecosphere.

Effective restoration and conservation require robust, scalable monitoring that can quantify baseline condition, track recovery trajectories, and detect early warning signals of decline or failure. Monitoring must also translate across scales, from local intervention plots to landscape-level mosaics, and incorporate biological indicators, habitat mapping, and emerging technologies.

My work contributes to indicator-based assessment (e.g., infauna for conservation management), large-scale monitoring frameworks, spatial modelling of seagrass occurrence, and remote sensing and drone-based mapping for linking habitat use, ecological pressure, and conservation outcomes.

Key publications (monitoring and assessment):

• Riera et al. (2025) Towards a more integrative environmental assessment: infauna as tool for Zostera marina conservation management. PLOS ONE.
• Huber et al. (2022) Novel approach for large-scale monitoring of submerged aquatic vegetation – a nationwide example from Sweden. Integrated Environmental Assessment and Management.
• March et al. (2013) A Bayesian spatial approach for predicting seagrass occurrence. Estuarine, Coastal and Shelf Science.
• March et al. (2013) Probabilistic mapping of Posidonia oceanica cover: a Bayesian geostatistical analysis of seabed images. Aquatic Botany.
• Mtwana et al. (2024) The 100 priority questions for advancing conservation, monitoring and research of seagrass ecosystems in Europe. Plants, People, Planet.
• Cossa et al. (2023) Monitoring using drones and machine-learning reveals an overlap between dugong foraging behavior and gillnet fishing. MEPS.
• Panyawai et al. (2025) RGB and multispectral UAV mapping of dugong foraging hotspots and seagrass beds in Thailand and Mozambique. Aquatic Mammals.

This research combines complementary approaches to ensure mechanistic understanding while maintaining relevance for management:

• Field-based restoration experiments
• Long-term monitoring of restored and natural meadows
• Flume experiments to isolate hydrodynamic mechanisms
• Seed harvesting, storage, and planting trials
• Integration of ecological and physical measurements

This work has been carried out in close collaboration with PhD students, postdoctoral researchers, technicians, and international partners. Training early-career scientists in field experimentation, underwater work, and process-based thinking has been a central component of this program.

Although much of the work is based along the Swedish west coast and the Baltic Sea, the mechanisms identified are broadly relevant to temperate and subtropical seagrass systems worldwide.

→ Link to Seagrass Ecology Lab
→ Link to People page

• Practitioners: Identify constraints and design site-specific restoration strategies.
• Researchers: Explore process-based links between ecology, hydrodynamics, and recovery.
• Students: Use this page as a structured entry point into restoration science.

Related blog posts, guidelines, and networks are linked throughout to support applied use and further exploration.