In honour of World Seagrass Day, we had the privilege of interviewing Dr. Leanne Cullen-Unsworth, CEO of Project Seagrass, a charity we’re proud to support at The P&M Group. Beyond learning about their incredible efforts, it was equally important for us to deepen our understanding and help raise awareness of seagrass’s vital role in our blue planet— what was once an unsung hero in marine research!
Founded in 2013 by three scientists dedicated to seagrass conservation, Project Seagrass has since grown into a thriving team united by a shared mission to protect and restore these crucial underwater ecosystems.
What is Seagrass?
As the only true marine angiosperm, seagrass is essentially a flowering plant, much like lilies on land. So, as you’d imagine, it thrives in shallow, soft sediment with plenty of sunlight—often in areas that serve as safe havens for boats. There are 74 known seagrass species worldwide, but a common misconception is they’re the same as seaweed, when in fact seaweed is an algae that requires a rocky substrate for attachment. Instead, seagrass plants have a complex root system that stabilises sediment, acting as shoreline protection—just one of the many ecological benefits it offers.
Where it all began for Leanne
My first introduction into seagrass happened to be quite accidental. During my PhD research on marine resource use patterns in Indonesia I quickly realised how dependent people are on seagrass meadows for the fisheries they provide, and as an easily accessible food resource. Seagrass could represent a good example of a sustainably used habitat where people are an integral part of this ecosystem and shouldn’t be excluded from it, nor do they need to be. Knowing this, it was incredibly interesting and mind-blowing that these meadows weren’t included in any management plans or given any protection.
That marked the beginning of my research journey, focusing primarily on the interaction between people and the environment, amongst many other key factors.
The benefits
Seagrass provides vast resources, and if we continue to care for it, it will keep delivering. It’s a real powerhouse of the ocean, ticking the boxes of 16 of 17 sustainable development goals! In the UK, for example, restoring seagrass can offer coastal protection by dissipating wave energy to reduce storm impact while also forming a dense barrier against coastal erosion.
More importantly, seagrass boosts biodiversity and supports marine life cycles, with 40,000 fish per hectare more likely to live in seagrass meadows compared to UK bare sand. There’s even biodiversity within surrounding sediments that play a crucial role in its recovery and overall health. We also know seagrass to store carbon in its leaves, yet the full extent of its carbon sequestration potential is still being studied, with ongoing research in the UK working to determine its effectiveness.
Research/actions
In the UK, our main focus is on seagrass recovery—understanding its decline, even its natural expansion in some areas, and the impacts driving these changes. Water quality remains the greatest global threat, as seagrass, like any plant, depends on unrestricted light. That said, our team continually conduct extensive research on restoration methods across various sites, using different techniques to determine the most effective approach for each location.
Not to mention our incredible seagrass nursery in West Wales as a hub for research on seed husbandry, storage, treatments, and sediment types to enhance germination. While less than 80% germination is disappointing in tree planting, marine restoration is far more challenging—so for us, 10% is a success! We also have a current PhD student researching greenhouse gas balances within seagrass systems subjected to varying water quality.
Internationally, we primarily serve as a technical partner to national organisations seeking answers to a specific research question. For instance, we’re currently nearing the completion a project across multiple Southeast Asian countries, where we are helping develop scientific frameworks to highlight the local significance of seagrass meadows. Our role includes providing guidance on data collection, analysis, and presentation to stakeholders.
At The P&M Group, as we continue to fundraise for the vital work of Project Seagrass in restoring seagrass and the benefits it offers to UK shorelines, you can also pledge your support here – Charity Sail Around The World | Give as you Live Donate.