Blue Carbon Restoration in Northern Ireland – Feasibility Study J. A. Strong1, K. Mazik2, N. Piechaud1, L. Bryant2, C. Wardell1, S. Hull2, M. Tickle2, E-M. Norrie2, H. McIlvenny3, and A. Clements3 National Oceanography Centre, UK (1) University of Hull (2) Ulster Wildlife (3) Saltmarsh ©Paul Corbett This report was funded by the DAERA Challenge Fund Contents Summary .................................................................................................................................... 8 Research Briefing ..................................................................................................................... 10 Introduction ............................................................................................................................. 22 Policy context ....................................................................................................................... 22 Northern Ireland’s Marine Plan ....................................................................................... 22 Future Developments: Northern Ireland’s Climate Change Bill, Environment Strategy/Environmental Improvement Plans .................................................................. 23 UK Marine Strategy .......................................................................................................... 23 UK Climate Change Act and the UNFCCC’s Paris Climate Agreement ............................. 23 International conventions and agreements: ................................................................... 24 The scope of coastal habitats in Northern Ireland to act as ‘blue carbon’. ........................ 25 Seagrass............................................................................................................................ 25 Saltmarsh ......................................................................................................................... 26 Shellfish beds ................................................................................................................... 26 Threats to coastal blue carbon habitats .............................................................................. 27 Project aims and structure of this report ............................................................................ 28 Part I: A review of seagrass (Zostera marina) restoration potential ....................................... 30 Distribution of Zostera marina ........................................................................................ 30 Habitat requirements....................................................................................................... 31 Global decline and threats to Zostera marina ................................................................. 32 Restoration Techniques ....................................................................................................... 35 Transplantation/ Seedling transplantation ...................................................................... 35 Artificial seed germination ............................................................................................... 39 Re-seeding/Seed planting ................................................................................................ 40 Seed collection ................................................................................................................. 40 Broadcasting / direct sowing of seeds ............................................................................. 41 Burial ................................................................................................................................ 41 Mechanical planting ......................................................................................................... 41 Deployment of reproductive shoots from buoys ............................................................ 41 Deployment of seeds in hessian bags .............................................................................. 42 Habitat modification ........................................................................................................ 44 Seagrass restoration feasibility ............................................................................................ 44 Challenges to restoration................................................................................................. 44 Importance of habitat suitability ..................................................................................... 45 Wider ecological considerations ...................................................................................... 47 Societal aspects of seagrass restoration .......................................................................... 48 Recommendations for Z. marina restoration ...................................................................... 48 Part II: Habitat suitability modelling ........................................................................................ 50 An Introduction to Habitat Suitability Modelling ................................................................ 50 Methods ............................................................................................................................... 50 Estimation of Extent and Habitat Suitability.................................................................... 50 Gathering the Predictor Variables ................................................................................... 51 Presence and absence data for species and habitats ...................................................... 55 Variable selection............................................................................................................. 61 HS model training, prediction and validation .................................................................. 62 Mapping extent ................................................................................................................ 64 Value range for suitable habitat ...................................................................................... 65 Results .................................................................................................................................. 66 Estimation of Extent and Habitat Suitability.................................................................... 66 Estimation of current extent ............................................................................................ 66 Habitat suitability (medium and high suitability) ............................................................ 75 Confidence layers ............................................................................................................. 75 Blue carbon hotspots ....................................................................................................... 87 Value ranges for medium and high habitat suitability .................................................... 87 Estimation of Extent and Habitat Suitability within Northern Ireland’s Inshore MPA Network ........................................................................................................................... 91 Discussion............................................................................................................................. 96 Estimation of Extent and Habitat Suitability.................................................................... 96 Potential Blue Carbon Value ............................................................................................ 98 Conclusion ............................................................................................................................ 99 Part III: Blue Carbon Restoration Feasibility Workshop ........................................................ 100 An Introduction to the Workshop...................................................................................... 100 Kelp Forests ........................................................................................................................ 101 Case Study: Help Our Kelp ............................................................................................. 101 Discussion Questions ..................................................................................................... 102 Summary ........................................................................................................................ 104 Saltmarsh ........................................................................................................................... 106 Case Study: Experimental saltmarsh restoration in Essex ............................................. 106 Discussion Questions ..................................................................................................... 107 Summary ........................................................................................................................ 109 Seagrass Meadows............................................................................................................. 111 Case Study: Seagrass Ocean Rescue .............................................................................. 111 Discussion Questions ..................................................................................................... 112 Summary ........................................................................................................................ 114 Shellfish Beds ....................................................................................................................