Eel Grass and Anchoring in Cawsand Bay, Cornwall

Appledore

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The local evening news had an article this evening about the damage anchoring in Cawsand Bay, Cornwall is doing to the Eel Grass. Apparently 'they' (I believe they said the local Gig Club and Princess Yachts) are intending to place permanent moorings into the anchoring area which will be permanently fixed by way of boring down into the seabed thus doing away with concrete block sinkers. No mention was made as to who will be able to use these permanent moorings, nor how many nor whether visitors will still be allowed to anchor off, similar I suspect to the Helford River.

Does anyone have any further details. It's a very popular anchorage, which I personally rely on to wait for the flood tide up the Tamar. So far no mention has been made of Seahorses!
 

oldharry

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Sounds like they are planning to use the standard helical screw type anchorage which has a very small seabed footprint. RYA has been invovled in quitea bit of research here: https://www.rya.org.uk/knowledge-advice/planning-environment/Pages/efm-overview.aspx

Generally speaking these moorings have to be matched fairly closely to the weight of the boat using them, so are unsuitable fro use as visitor moorings without close supervision. Is Cawsand part of the Plymouth Harbour area? If so the moorings will be laid under their jursidiction, and the HM can impose any controls or restrictions on anchoring he sees fit. If on the other hand it is 'open sea' then other than they must obtain a licence from the owner of the seabed - usually but by no means always Crown Estates - but there is nothing anyone can do to stop you from continuing to use the anchorage in the vicinity of the moorings, whatever the mooring owners may say. But equally there is very little you can do to object to the moorings either, as they are effectively exercising that same right. This is at the core of the Studland argument - the continued right of anchoring in open water as part of the constitutional right of free navigation in UK waters.

As to the accusation of anchor damage to the eelgrass, see the BORG website for more information!

You could contact RYA Legal Department to ask them what the situation is. They can and will apply pressure on MMO to ensure anyone can use the anchorage if it is open sea. If it is part of Plymouth Harbour, then the HM's Office should be able to clarify for you.
 
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Appledore

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Thanks for your response OH. I thought you might be 'on the case'!

Cawsand Bay is within the Plymouth Dockyard Area so will, I assume, come under the juristiction of the QHM. I shall listen out for more details and thanks again for your response.
 

doug748

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I have not seen the story.

There has been very little work on eelgrass in the Sound just some undergraduate type stuff and a Natural England study from 2009 which sought to establish a baseline and, of itself, is no yardstick whatever. It is overdue to be followed by a repeat study but nothing has been heard:

publications.naturalengland.org.uk/file/4991709209952256

Perhaps we have junked science and put measures in place with a vague idea that it may do some good, perhaps it is Princess Yachts doing a bit of PR. The moorings in Cawsand Bay are not tenable over the winter months so I am guessing that Princess are funding some nice summer moorings for the Gig Club use - but that is just a guess
It would be good if someone could link to the story

Maidment was trying to drum up money for a seahorse study with the Marine Aquarium , about 4 years ago, but seems to have got nowhere.

I would not panic over this one, it is a large and important anchorage used commercially and the QHM Plymouth have acted with discretion in the past:

https://www.royalnavy.mod.uk/qhm/pl...raft-anchorage-off-plymouth-hoe---information
 

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I saw that on the news, but they only mentioned existing moorings I didn't hear them make any mention about anchoring . . . . . . . . . I know I'm of an age where I am prone to nod off but pretty sure I was awake throughout that bulletin.

There was no mention of seahorses but their main push to save the eelgrass was because it uses more carbon dioxide than a rain forest apparently, or something along those lines, basically their main reason this time is to combat global warming.
 
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Appledore

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That was the point Pete, no mention of anchoring, but I'm sure there was a clip of an anchor on the seabed - could have been anywhere I suppose!

There aren't that many permanent moorings in Cawsand, and I think this year less than there used to be. It used to be quite easy to pick an unused one up for a short stay, but not anymore.

Any mention of Eel Grass (or Seahorses) makes me wonder what might come next.
 

Scillypete

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That was the point Pete, no mention of anchoring, but I'm sure there was a clip of an anchor on the seabed - could have been anywhere I suppose!

There aren't that many permanent moorings in Cawsand, and I think this year less than there used to be. It used to be quite easy to pick an unused one up for a short stay, but not anymore.

Any mention of Eel Grass (or Seahorses) makes me wonder what might come next.

Yeah, saw the clip of the anchor which they used more than once probably a stock photo. It didn't seem to be aimed at anyone anchoring as they mentioned that the rame gig club are responsible for moorings in the bay, of which there are a few, and the emphasis was on moorings. . . . . But like you say any mention about protecting eelgrass does make you wonder where it will end.

One particularly hot weekend last May I was there and there must have been at least 150 boats at anchor it was as if the tamar and all marinas had emptied out and gone to cawsand
 

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A busy summers weekend will be interesting as 50 boats will be wander round looking for a place to drop the hook.

Some of them dont do it very well either!

On the hook last year in Cawsands when a Corvette MoBo faffed about and dropped the hook. I said to First Mate that I though he should have let out more scope.

The couple on board launched their dink and took the dog ashore.

A nearby yacht upped anchor and moved quickly before the Corvette hit his boat and another was ready with the fenders and boathook as the Corvette slipped quietly by at about a Knot.

Someone went ashore, found the Corvette owners who came back, got aboard and then proceeded to refit the dink on the davits before stopping the dragging.

I estimate their boat dragged 250 metres before they returned, and about 150 metres after.
 

doug748

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I have not managed to find anything about the story in the local paper or news but there is this:

https://www.scubaverse.com/new-eco-...replacing-damaging-anchorage-2/?cn-reloaded=1

Dr Solandt:
“We believe we’ll be protecting something like 0.5km square of seagrass bed with our project in the first year. We hope to cover the entire bed within three years, if the project proves successful,” says Dr Solandt. “The seagrass bed is considered to currently be in ‘unfavourable condition’ by Natural England

However the 2009 NE study said this:

"Of the four Zostera marina beds within Plymouth Sound and Estuaries SAC surveyed in July 2009, namely Cawsand Bay, Drake’s Island, Cellars Cove and Red Cove (north & south), all were found to be in a healthy condition. There was no sign of the wasting disease caused by the slime mould/fungus Labyrinthula macrocystis,"

Just to update post 4, there was a follow up study ( using some different methodologies) from Natural England
It said this in 2012:

"It is recommended that the seagrass beds within Plymouth Sound SAC are assessed as being in Favourable Condition for all attributes with the exception of infection scores/percentage cover, where the condition of the attribute is unknown..."
If anyone has a link to any work later than 2012 that would be interesting.

From the local MPA (Marine Protected Site) joint site:

"The Plymouth Sound is a very popular site for recreational boaters, but we also have important areas of subtidal seagrass that overlap with anchoring and mooring locations. Research has shown that the effects of anchoring and mooring can be devastating to seagrass beds as a result of scour from the chain and anchoring dragging up the seabed."

So, more general, and questionable, ideas applied to specific sites. Worth noting that the small and intensively anchored Cellars has some of the best density of grass.

Having said this stuff, the seagrass in Cawsand Bay is in quite a small area to the south of the anchorage.
At the moment.
 

Tranona

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It will be interesting to see how the EFMs work in this location. It is true that conventional sinker and chain moorings damage the seabed and eel grass. This is shown in the work done in Studland. However it is atypical there because the moorings are in shallow water, generally less than 2m and a range of nearly 2m at springs. So the scouring radius at low water is large. This high range to depth ratio is the main reason together with the narrow weight range why EFMs are not considered suitable for general use moorings such as visitor moorings.

I don't know what the depths and range are in this proposed location, nor whether there will be any restrictions on how they are used, but one would hope that there will be a sound monitoring mechanism to report on how they work out.
 

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I don't know what the depths and range are in this proposed location, nor whether there will be any restrictions on how they are used, but one would hope that there will be a sound monitoring mechanism to report on how they work out.

I usually anchor in about 5 meters (about an hour before LW last time would have been 1 meter (+4)), which is about as close as I can get for my 1 meter draught.
 

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Thanks, doug748, for the eelgrass survey references. There is in fact very little published research into UK eelgrass, many fewer actual papers than people who queue up to pontificate about how threatened it all is. The report of the diving survey done in summer 2009 (of which I was not previously aware) can also be accessed from http://publications.naturalengland.org.uk/publication/5738192108519424 and I've added it to our BORG database, as it gives very useful baseline data. I've not read it properly yet, so no further comment at this stage, except to wonder why, if NE can commission a proper survey in Plymouth Sound and estuaries, they have failed to do so in the very controversial Studland Bay. Worried about what it might reveal, perhaps?

There was mention earlier about eelgrass and global warming: a recent paper which Old Harry drew to my attention (https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0204431 ) made some estimates of how much CO2 is sequestered by all the eelgrass in the UK, and if I got my arithmetic right when you convert the number of tonnes of carbon to a % of the UK annual carbon emissions, it comes to about 0.04%. A drop in the ocean, as it were, aka diddly-squat.
 
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doug748

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No problem MS. CO2 - figures are taken out of context and then repeated as significant facts, seems to be becoming standard practice!
Appledore, most of the seagrass is inside the 4m contour, almost all within the 5. A link to the 2012 study, PDF, is here:

publications.naturalengland.org.uk/file/4797619915194368

It shows a good chart of the extent of the grass.
 

alahol2

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Appledore, most of the seagrass is inside the 4m contour, almost all within the 5. A link to the 2012 study, PDF, is here:
publications.naturalengland.org.uk/file/4797619915194368
It shows a good chart of the extent of the grass.

Just had a quick skim through that report and what is noticeable is the number of times the report states that no evidence of anchor scarring was found by the survey. That statement was invariably followed by a string of excuses as to why there was no evidence. The only excuse that was noticeable by its absence was the possibility that anchoring causes no long term damage. The overriding impression is that they want to find evidence of damage and are very disappointed when they don't. To me, that doesn't sound like a very scientific approach to report writing.
 

oldharry

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Just had a quick skim through that report and what is noticeable is the number of times the report states that no evidence of anchor scarring was found by the survey. That statement was invariably followed by a string of excuses as to why there was no evidence. The only excuse that was noticeable by its absence was the possibility that anchoring causes no long term damage. The overriding impression is that they want to find evidence of damage and are very disappointed when they don't. To me, that doesn't sound like a very scientific approach to report writing.

... but one which I fear we see too much of in this game. As we all know we keep being told anchoring is an important factor in eelgrass studies, yet nobody has actually researched it properly. There are many questions: weight of anchor , length and material of rode, what difference is there between the various types: there are reports which just state that susch and such a type does more or less damage, but no supporting research to actually determine which is the best anchor for us to use to minimise disturbance.
 
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moomba

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... but one which I fear we see too much of in this game. As we all know we keep being told anchoring is an important factor in eelgrass studies, yet nobody has actually researched it properly. There are many questions: weight of anchor , length and material of rode, what difference is there between the various types: there are reports which just state that susch and such a type does more or less damage, but no supporting research to actually determine which is the best anchor for us to use to minimise disturbance.

There has been numerous studies in the Mediterranean about anchoring and the destruction of a species close the the eel grass in the UK , although the differences are substantial in that the eel grass in colder waters tend to grow back faster and have more tolerance to pressures put onto it. but in science you can make a correlation between the 2.
The 0,04 percent of UK eel grass taken up CO2 can be multiplied by the number of eel grass beds around the world , it would be like saying I have only thrown one cotton bud in the sea , its ok. (accumulate effect)
The reason eel grass beds are now being looked at around the UK is that the environmental agencies have a duty of care to select areas to protect , this comes from central Government and the EU directives to protect he environment. Now clearly this can, and will affect people and businesses around the area, without sounding unconcerned for these people , it happens all the time around the UK were areas are selected fro National parks ,etc and there will always be the negative arguments between those, that use the sea and land and those that want to protect it.
Balance as always needs to be found for all.
 

Tranona

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There has been numerous studies in the Mediterranean about anchoring and the destruction of a species close the the eel grass in the UK , although the differences are substantial in that the eel grass in colder waters tend to grow back faster and have more tolerance to pressures put onto it. but in science you can make a correlation between the 2.
The 0,04 percent of UK eel grass taken up CO2 can be multiplied by the number of eel grass beds around the world , it would be like saying I have only thrown one cotton bud in the sea , its ok. (accumulate effect)
The reason eel grass beds are now being looked at around the UK is that the environmental agencies have a duty of care to select areas to protect , this comes from central Government and the EU directives to protect he environment. Now clearly this can, and will affect people and businesses around the area, without sounding unconcerned for these people , it happens all the time around the UK were areas are selected fro National parks ,etc and there will always be the negative arguments between those, that use the sea and land and those that want to protect it.
Balance as always needs to be found for all.

You are still catching up - there is nothing new in what you say here. Suggest you actually read the studies on anchoring in the med before you suggest they have any relevance to the issues (if there is an issue at all) in the UK.

The fact is that none of the studies in the UK have identified anchoring as an issue. Many would like it to be and have stated that it does, but without any evidence to support their claims.

But then we are going over old ground. If you claim decisions should be based on evidence then you need the evidence. If there is no evidence do not make the claims.
 
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