World Oceans Day – Marine Monitoring on Higher Education Placement

James King is on a higher education placement in the marine monitoring team at Natural Resources Wales. To mark World Oceans Day (8 June 2022), he tells us about his day as the Dive Technical Assistant on the Dive Survey on the Llyn Peninsula.

"Working on the dive survey for the north of the Llyn peninsula in North Wales is quite special. It is an important community within the Pen Llŷn a'r Sarnau Special Area of Conservation (SAC) and a priority feature for monitoring. It is designated an Annex I habitat under the Habitats Directive which ensures the conservation of the rare, threatened, or endemic animal and plant species found there. The area also has statutory protection from commercial fishing.

The site is monitored every year because it is part of a horse mussel (modilolus modiolus) reef, and back in June, I was the Dive Technical Assistant on the dive that surveys the area.

The horse mussel reef at Pen Llyn is densely packed with live and dead horse mussels and is diverse in associated fauna. These are the southernmost Horse Mussel reefs in the UK. The data collected during this survey monitors the health and extent of these reefs, which are an important biodiversity hotspot. We protect and monitor sites like these to support the health of our seas in face of biodiversity loss and the impacts of climate change.

As the Dive Technical Assistant, I prepared, serviced, and maintained the day’s equipment that was needed before we set off. Once on board, I assisted the divers, the dive supervisor, and the boat skipper by preparing equipment and communicating with divers from the surface once they were in.  

The conditions were ideal - a hot sun and lack of wind made for a calm sea. The journey to the dive site was a 2-hour trip and was slightly delayed because a Risso’s dolphin came to say hello! It was about 3m long with the distinct stocky body, large blunt head and sickle shaped dorsal fin that makes it an easy species to identify. After riding parallel with Pedryn the dive vessel, the lone dolphin went off to explore elsewhere, and left us to the task of finding our survey site.

Once onsite, I assisted the skipper in laying a ‘shot’ buoy, which the divers used to descend. I helped them prepare to take the plunge by ensuring they had all the equipment they needed. These included cameras, temperature loggers, recording sheets and quadrats.

Quadrats are square grids of metal that let the surveyors monitor how things are changing from year to year. Underwater, the divers place the quadrats in the same spot as the previous years by lining them up with the markers on the reef. Next, they record the species present on the recording forms and with the cameras. Recording things in this way helps us build a long-term picture of what’s happening at the site so we can manage natural resources in a more sustainable way.  

Once the dives were completed, I retrieved the shot buoy and stowed all equipment for the transit back to port. That evening, we offloaded the data that was recorded by the temperature loggers which have been recording the sea temperature for the past year, downloaded the videos and images from the cameras, and fettled equipment that needed attention for the next day’s diving.

All in all, a good day at sea, and made more worthwhile knowing the data collected supports the decisions that improve conservation in Welsh waters and build the resilience of marine ecosystems.”

We are launching a new programme for Marine Nature Networks and have a number of positions available. If you're passionate about making a positive difference to the marine environment around Wales, check out the available roles here.