Horse Island & The Pink Seaweed

Maerl the pink coral-like nobbly stuff is  precious.

Sea Change, SCFF and SubSea.TV have collaborated on surveying Wester Ross Marine Protected Area since its creation in 2016. Our focus has largely been on surveying maerl because of its importance to commercial fisheries and the whole ecosystem. The film above was made as a collaboration between us, local fishermen, and Wild Fish groups who share our concern about the Horse Island salmon farm proposal. (See the credits at the end of the film).  The video shows some of the survey discoveries we have made and how this relates to the story of why maerl, the pink coral-like nobbly stuff, is worth protecting.

Maerl is what makes Wester Ross special.  It is also possibly one of the reasons the area was once one of the richest areas with abundant herring and whitefish fisheries.   Herring spawns on maerl, which also supports other finfish too. The Pink seaweed has international scientific and legal importance due to its role in supporting hundreds of other species too. The preciousness of maerl is enhanced by the fact that so much of it has been damaged elsewhere (it was once dredged to be used on gardens instead of lime etc).  How little we knew then! A cautionary tale given there is still a lot to learn.

Thanks to Andy’s interest in macro-photography we can also glimpse the abundant life maerl supports amongst the pink nobbly-noodles,  a small amount of what he shot is visible in the film.

For the really curious amongst you who wonder about the fish farm nutrients mentioned in the film and what the impact might be, have a look at the one minute film below which shows the red and brown algae growing on maerl in the channel in the Summer Isles between Tanera beg and Fada. We have also seen this in Loch Ewe too.

It is vital to note that there is no proof that the algae growth is caused by nutrients from the fish farm, but we definitely need to encourage further investigation.  The marine scientist observing this during our survey said”

My general feeling, which I cannot prove at the moment without further survey, is that the maerl beds around the Summer Isles are being stressed. I believe that  any increase in nutrient levels, sediment deposition or reduced water clarity would be detrimental to the long term survivability of the these beds and putting a new fish farm within a short distance of an existing maerl bed would be a bad idea.  

He also said:

When we dived on the maerl bed between Tanera Beg and Eilean Fada much of the maerl was covered by filamentous algae, mainly reds but also some browns. I had noticed something similar over the maerl bed in Scotnish narrows in Loch Sween which I’d dived earlier in the year. The Loch Sween maerl is nowhere near a fish farm and I think that the luxuriant algal growth noted was probably something to do with the warm sunny summer we had.  Growth of algae over the summer is perfectly natural phenomena and the maerl can generally cope. However if there is too much filamentous algae it will hinder maerl photosynthesis and when it dies off over the winter it could have a major detrimental impact on the maerl bed. Normally there will only be excessive algal growth every few years which the maerl can cope with but increased nutrient levels and warming seas could result in increased algal growth,  maerl die off and loss of the bed.  Unfortunately it is very difficult to work out exactly what is going on and more importantly predict future changes.

I know Heriot Watt are currently carrying out research into the impact of rising temperatures on maerl survivability amongst other projects.   What I would like to do is dive on the Tanera Beg maerl bed in the winter/early spring and assess the ratio of live to dead maerl, something which is difficult to do non-destructively in the summer. “ 

Thanks from Sea Change goes to:

The surveys which supplied the footage for “Horse Island & The Pink Seaweed” would not have been possible without Sea Change’s partners Andy Jackson of SubSeaTV, Alasdair Hughson of the Scottish Creel Fishermen’s Federation and Keltic Seafare, as well as a huge collective effort. Andy and Alasdair helped to coordinate the surveys with Sea Change. This especially applies to the surveys around Horse Island in 2016 and June 2018 which support the citizen science discovery project in Wester Ross Marine Protected Area. More of Andy’s beautiful video from the June 2018 survey (including Graham Saunder’s photos) is shared on another post called An Ecosystem and Flowers of the Sea Forest! Both films were made by Little Green Island films.

In order to make the Maerl film above, the June  2018 Survey was critical:

Special Thanks for Donations for the film making and surveys: 

Wester Ross Salmon Fisheries Board for their support covering the music costs.

Gabby Rex for donating the funds for the survey’s technical equipment;

Andrew Hopetoun for funding Andy’s expenses to come to Wester Ross to film.

Accommodation given: Brian Wilson, Reiff Beach Cottage (Sara Nason).

Boat, Air Supply and divers support: Thanks to Keltic Seafare for air supply and Pete Watson for generously driving it to us. Thanks also to North Minch Shellfish Assoc and Robyn and Scott for their day out on Goldseeker…

Thanks also to Tanera’s Restoration Project for their support in the loan of a boat & a donation towards our costs.

Thanks goes also to Marine Scientists, Divers too numerous to mention but Owen Paisley and Lewis Press….amongst many others..Others have been involved in the surveys referred to in the film too. They will have particular thanks on pages referring to the specific surveys however those who helped support, guide and provide knowledge in preparation for the making of this film are: Robyn Dutton and North Minch Shellfish Assoc, Donald Rice of Dundonnel, Richard Luxmoore (National Trust for Scotland),  Gary Lewis an Ullapool based scallop diver for his knowledge on the seabed in Wester Ross MPA, Keith Dunbar and John McIntyre and many more …