Advanced Moorings for Environmental Growth
Format of the day:
- 29th January at Pennycomequick, Falmouth, was the third meeting of the Advanced Moorings Tevi Challenge Network (CN).
- 15+ organisations attended the workshop to build on the discussions held in the first and second meetings
- The format was a facilitated open discussion between all attendees
Overview of the issue:
- Conventional (thrasher chain) swing moorings scour the seabed as the chain (even without a boat attached) moves around the mooring due to tide and wave movement, thus preventing the growth of seagrasses and other marine flora and fauna within the effected seabed.
- Seagrasses, particularly eelgrass, are an important part of the marine ecosystem and provide a range of essential ecosystem services. They are a significant carbon sink, a nursery ground for commercial fish species, a haven for threatened and protected species, as well as providing coastal defence from wave erosion. 92% of seagrasses have been lost since 1930.
- Advanced Mooring Systems (AMS), which come in a variety of designs, lift the riser / thrasher chain section of the mooring system off the seabed, thus allowing for the regrowth of seagrasses where conditions are favourable; sheltered, good light levels and a sandy or muddy seabed.
Aims of this CN:
- The overarching aim of this CN is to accelerate the installation of AMS by demonstrating their importance ecologically, their effectiveness regarding boat safety, and their impacts on moorings maintenance.
- During the course of the CN discussions key barriers to the uptake of AMS have become apparent:
- Concern regarding whether existing AMS solutions are appropriate for deployment in unsheltered and high tidal range harbours due to the low numbers of trials and the challenge of accessing the findings of these trials.
- Lack of knowledge regarding locations of eelgrass in order to understand where the deployment of AMS would be most effective.
Outcomes of CN meeting III:
- Attendees still agree on the ecological benefits of AMS but
- Outlined concern regarding;
- Boat behaviour on the mooring particularly where there may be a mix of conventional and AMS moorings side by side.
- The performance of an AMS in more extreme conditions
- Cost of replacing existing systems verses being able to retrofit them
- Outlined benefits regarding:
- Potentially lower maintenance costs, depending on AMS
- Being ahead of customer sustainability awareness and pressure
Next steps for this CN:
- Create a report summarising the available AMS solutions and costs, safety and boat movement outcomes from AMS trials, and the ecological impacts from AMS trials (Tevi and Natural England).
- Create a chart overlaying known communities of eelgrass on top of Carrick Roads, River Fowey, Helford River, River Tamar, Lynher River and relevant creeks / tributaries charts (Cornwall Council, Natural England and Tevi).
- Create a report modeling how known AMS could behave in the participating harbours listed within the rivers and tributaries listed above (Tevi and Marine I / external consultant)