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A New Way to Film Marine Life

An opportunity to work with the BBC on its Beach Live: Jurassic Coast Revealed, gave Sonardyne’s Andy Marsh a chance to trial and prove an idea he’s been working on in his spare time; using his experience as a marine videographer and subsea equipment designer, aided by Sonardyne technology, to find a better way to film and monitor the marine life around our coasts.

Filming marine life without being invasive is not an easy task. If you use a remote operated vehicle (ROV) you kick up the silt and cannot see the marine life. Divers have a limited amount of time in the water and even when they’re there, they’re not seeing the wildlife as it acts when it’s undisturbed.

For about 10 years, in my spare time, I’ve been working with the Dorset Wildlife Trust, monitoring and recording Dorset’s marine life. I have also dived with Seasearch, a programme through which scuba divers in the UK can help to monitor marine life. Each year, we look to see if there has been any change in the seabed, if it’s more or less healthy or if there have been any other changes, and record these.

EMBED WT Andy 0110I used to film these dives using an underwater video camera, which could then be used by researchers. But, diving can be cumbersome. There’s so much kit to take down with you and it becomes quite complex. You also scare the marine life – you’re a big bulk that sounds like Darth Vader with a cold. I wanted a non-invasive way to film marine life.

Working with the BBC on the Beach Live, I created a system called SharKam, which has two high definition underwater surveillance cameras that are capable of filming at a depth of up to 45 metres. They are both mounted on downward facing tripods and connect to a surface Wi-Fi mesh using an Ethernet umbilical, either direct to a vessel or via a buoy.

What’s great is that, using SharKam, you can use any laptop (or even a smart watch) to connect into the mesh and view what the camera is seeing, live. If there’s something you want to save, then you just press the record button and it is stored locally. We could also tilt, pan and zoom the cameras without disturbing the marine life – so you see it how it behaves normally.

To film some marine life, it’s hard to do it any other way. For example, there’s an area the size of two football pitches filled with brittle stars, a type of starfish, with “arms” up to 60 centimetres long, off Kimmeridge Bay in Dorset. They live on the seabed and reach up with their tentacles to feed. Because they feed by filtering the sea water, they live in areas with strong currents, which makes filming by divers, while trying to hang on to a surface marker buoy with one hand and the camera with the other, without falling, difficult. I know – I’ve tried. Instead, I tried filming them with SharKam off a boat with a live link. It was not only easier, I got some beautiful images of a brittle star feeding.

Like all live filming, there are challenges. During Beach Live a gale meant we couldn’t get to where we wanted to film initially. So, for some time during Beach Live we just had barren seabed, as people who watched the live-aired programme back in July, would have seen.

But, at another site, we hit the jackpot. A beautiful young conger eel came up and ripped our bait clean off the seabed leg frame. Next, we got three catsharks swimming around the frame at the same time. That was a great sight – I have never seen three in one place before.

Then, an edible spider crab arrived, trying to eat what was left of the bait and a scrap started between it and an edible crab, with the catfish also joining in on the action. It was quite an episode. Myself and the BBC camera crew were jumping up and down on the vessel with joy to see this. You just don’t see this kind of activity as a diver or with an ROV. That was the highlight of the week.

We couldn’t have done it without Sonardyne’s support, both in terms of time, as I had the help of projects manager Tom Bennetts, and equipment.

For my work with Seasearch and the Dorset Wildlife Trust, we want to do more than just see marine life, however. While it’s important that we see what is on the seabed, it’s even more important that we know where that sighting is, so we can then monitor it. During the Beach Live filming in Lyme Bay, we used a Sonardyne Nano transponder on the seabed camera frame, and a Micro-Ranger transceiver hung from a pole on the boat, so we knew the exact location of where we were filming.

Nano is Sonardyne’s smallest, rechargeable acoustic transponder. it's under 160mm-long, 52mm–diameter and weighs just over 200 grams, making it easy to transport and use. Mini-Ranger 2 is a sixth-generation (6G) Ultra-Short BaseLine (USBL) underwater positioning system, able to track up to 10 subsea targets, with a range of up to 995 metres, which is extendable. It's a great solution for small vessels working in nearshore waters – and for operating SharKam.

EMBED 2 lyme regis 924431 1920No one has done this before. Being able to know the exact location of what you are filming is very important, because it means we can monitor the health of the seabed in a non-invasive way over time. We can also feed this information into a system called DORIS (DORset Integrated Seabed Study). DORIS is a collaborative project between Dorset Wildlife Trust, the Maritime and Coastguard Agency (MCA), the Channel Coastal Observatory (CCO) and the National Oceanographic Centre, Southampton (NOCS) to map Dorset’s coast. The DORIS data base is based on side scan sonar data of the seabed, over which photos showing marine life can be overlaid, exactly where they were taken. It’s similar to Google Earth – and can in fact be viewed online using Google Earth. If you were a diver getting these images you could be 10, 20, 30 metres out and you would just not be able to find the same spot the next year to monitor if it had changed. Using the Nano and Micro-Ranger, we can properly map and track marine biodiversity in a useful way.

This is important for areas like Lyme Bay, which extends of 65 kilometres and where Beach Live was filmed. Here, cold water from the north meets warmer water from the south, resulting in cold and warm water species living here. Its reefs and the associated fauna are considered to be nationally important. It’s home to rare and protected species and seven species of coral. It has been designated as a candidate Special Area of Conservation (cSAC) and a large proportion of it is subject to a mobile fishing gear ban. We need to monitor areas like this.

By Andy Marsh

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