Surveying Advanced Mooring Systems

30 June 2021  /  By Jean-Luc Solandt, Marine Conservation Society

Jean Luc Solandt, MCS

Jean Luc Solandt, MCS

As part of ReMEDIES, Jean-Luc Solandt of the Marine Conservation Society took a dive at Cawsand Bay to record the effects of introducing new Advanced Mooring Systems which reduce impacts on the seabed and will hopefully lead to seagrass growing back…

There were six volunteers and me. On the surface, and all around us, Cawsand had many day trippers – mooring, anchoring, jet skiing, swimming, fishing. Lots of humanity having a lovely time. They outnumbered us at least one hundred to one.

Nothing wrong with people enjoying the sea, right? It’s healthy, gives us tremendous well-being and offers us an experience of something a little wilder than our comfy lives.  But, some recreational activities impact on important seabed habitats such as seagrass.

We know that some boat moorings can ‘scour’ the seabed and prevent the growth of seagrass blades. So, we’re working locally with volunteer mooring holders to simply lift the moorings off the seabed by attached submerged buoys (see illustration, right).

The dive
Our dive was aboard ‘Red Alert’ with skipper Danny and logistics coordinated by Mark Parry – the Project Manager of the Ocean Conservation Trust. We’ve received funding for this work from Princess Yachts (between 2018 and 2020) and the EU LIFE Programme (2019 – 2023).

Setting out from Bovisand Fort at about noon, we started diving around an hour later. Each dive buddy pair dropped in with pencil and slate (to record the information), quadrat (a heavy metal square that we use to quantitatively record a set area of seabed seagrass), a measuring tape (to measure the length of seagrass blades), and a transect tape (to measure up to 9m distance from the base of the mooring) – oh and a camera. A lot of kit to take underwater!

On the dive, we lay out the transect line 10 metres from the pin at the base of the helical screw pile out to four points of the compass. At six intervals along the transect we record the amount of seagrass, its shoot length, sediment depth and any unusual species in each quadrat. Twelve quadrats per mooring – with the dive taking an hour. There were three buddy pairs, and we did two moorings for each buddy pair, covering all five Advanced Moorings in Cawsand Bay as well as a nearby ‘standard’ mooring to compare and contrast the abrasion from that mooring to the Advanced Moorings.

Anchor on seabed. Credit Jean Luc Solandt

Anchor on seabed. Credit Jean-Luc Solandt

On the first dive we were almost trawled up by an anchor passing right under my face, nudging my shoulder on the way through. It stirred up the sediment in the seagrass bed and showed me – more closely than I wished – the issues related to lack of awareness. Lack of awareness of where seagrass beds are, of recognising a ‘diver down’ buoy (that was above our heads), of how to set an anchor, and of how close one should be to a mooring to set an anchor (the anchor only passed about 3 metres from the base of the mooring we were working from).

I wasn’t angry. How can you be? It’s just something to do with our known normal use of the sea based on what we see at the surface without considering what is on the seabed. Without mariners being asked to sit a ‘marine highway code’, this problem will persist, particularly on the sunniest, busiest days. And we understand the desire to get that boat anchored, feel secure and connected to the sea, and then rest. What a lovely way to spend a sunny day at sea!

What is ReMEDIES doing to address the issue?
Well, we’re producing an up-to-date map of seagrass bed locations, installing Advanced Mooring Systems at Cawsand Bay, Cowes and other Marine Protected Areas, using Advanced Moorings for the Voluntary No-anchor Zone at JennyCliff Bay in Plymouth Sound where we planted seagrass seed bags in April, as well as in the shallow waters of Osborne Bay on the Isle of Wight. We’re engaging with boaters through webinars and face-to-face events to raise awareness of sensitive seabed habitats, share best practice and find out more about the impact of boating practices on the seabed, and evaluating the impact that our work is having. You can learn more about boating best practice in The Green Guide to Anchoring and Moorings [LINK] produced by The Green Blue as part of ReMEDIES.

Together we can foster change and help our seagrass beds ‘regrow’. After all they are the lungs of our coasts, absorbing huge volumes of carbon. We need to let these habitats that help us to live rewild. The Advanced Mooring Systems are starting to show us that boating and seagrass can go hand-in-hand.