Underwater Videos

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Our Aerial Images page shows the expansion and consolidation of the eelgrass beds in Studland Bay in recent years. We now support this with an Underwater HD Video Sample Survey which the Boat Owners Response Group conducted on 18th July 2016. We used a Nikon AW120 underwater camera mounted on a pole and deployed from a small inflatable dinghy which drifted downwind in a series of passes, such that the lens was about 1.5 metres (5 ft) beneath the sea surface. Five passes are reported here, average run length 70 metres, covering a total of over 350 m of seabed in different inshore parts of the Bay. The camera was equipped with a GPS unit and the position of the start and end of the runs was recorded by the camera. (For readers not familiar with the appearance of eelgrass, just look for the long grass-like leaves in the images. Also for those uninitiated in the finer details of eelgrass life, the conspicuous whitish flower- or star- like objects are actually snakelocks anenomes, which are commonly found growing on eelgrass leaves. The actual flowers of eelgrass are inconspicuous, and may just be seen as evenly spaced irregularities along the edges of some leaf blades).

There were two main objectives. The first was to provide photographic “ground truthing” of the aerial image conclusions, showing that the green areas in the aerial images are indeed predominantly eelgrass (seagrass Zoster marina). The second was to test the assertions that the eelgrass in the Bay is damaged and declining, leading to the absence of seahorse sightings in recent years, an assertion continually being made by the Seahorse Trust in the person of its Director, Mr Garrick-Maidment, but never supported by any proper photographic evidence. Our  video evidence will also test the opinion expressed by Natural England that eelgrass is “highly vulnerable” to anchor damage.

The positions of the video runs are shown on the diagram below, and links are given to the YouTube videos. They clearly show healthy, abundant eelgrass over extended areas, which include the main study areas used by the Seahorse Trust (SHT). These images give the lie to the SHT’s claims of doom, gloom and destruction – and which they have never supported with photographic evidence, apart from a handful of images of unclear provenance showing small areas of alleged damage.

These videos from the moorings area were in comparatively shallow water and taken near low tide, so the camera lens was about 4 ft, 1.2 m, above the seabed. This means, after correcting for underwater refraction, that the videos show strips of seabed about 40 inches or 1 metre wide, from the left hand to the right hand edges of the frame. They are effectively close-ups, and the size of any discontinuities in the eelgrass cover can be judged against that 1 metre width. There is not a single linear scar visible, in stark contrast to SHT tales of “anchors being dragged through the seagrass ripping it up”.

As well as raising serious questions over the integrity and credibility of the SHT’s reports, the images totally undermine the Natural England view that eelgrass is “highly vulnerable” to anchor damage, since anchoring has been going on in these areas for decades, and the eelgrass is thriving, as shown by the aerial, and now underwater, images.

We believe it important to shine the light of real and recent evidence on the exaggerated and false claims that are being made about the eelgrass in Studland Bay. We encourage all readers to click on the links, view the videos – which are HD and can be viewed in full screen mode –  and enjoy the images of healthy, flourishing eelgrass.

A location map based on the Google Earth 2009 image of the Bay is shown, clickable links to the videos are beneath. Note that the large bare patches in the aerial image are caused by the ground chains of the mooring buoys in the Bay. This is a well-known effect of limited and stable extent, and not connected with anchoring.

A full, more detailed report of this work is available here.

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Pass 1, 60 m long, link https://youtu.be/HJwFicucaHw

Pass 2, 73 m, https://youtu.be/CNX00jizWE0

Pass 3, 43 m, https://youtu.be/wTZqPi3ieJM

Pass 4, 107 m, https://youtu.be/A5LRMse3N1w

Pass 5, 75 m, https://youtu.be/EiXItx3hFbE

It will be seen that abundant eelgrass is growing throughout all five passes. The growth is however not homogenous and uniform, which is common with eelgrass beds. For an interesting example of an eelgrass bed in the Helford River which offers various sub-habitats for the various creatures in the short film, see https://www.youtube.com/watch?v=w1f0J7UP7LM .

Shown below is a 2009 Google Earth image of patchy eelgrass at the far north end of Studland Bay: this is an area where boats just do not anchor (it’s too constricted and shallow).

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