Collecting citizen science data as a free diver

citizen science cornwall free diving seagrass Apr 26, 2024

I first became curious about what I think of as the 'underscape' while sea swimming in 2019. The following year, I finned my way through a beginner freediving course and a Seasearch Observer course followed in 2021.

The morning of this particular day, my dive buddy Amy and I head for a regular spot, Grebe Beach on the Helford River. I can already see from the shore that the vis is sub-par, but I love diving here. I've put in more than one form for this spot. There's a great diversity of life to be seen and often something new to record.

Underwater at Grebe Beach, Cornwall

Underwater at Grebe Beach, Cornwall.

On entering the water, we head left, hugging the shore and inspecting one of the large boulders whose crown just peaks on a super-low tide. There is some oarweed here, and even a little sugar kelp, but it's sparse. This location makes a change from the kelp beds I so often spend my time in. A smattering of sargassum and thongweed also hem the seagrass.

Elspeth free diving in Cornwall.

Diving on less than a lungful of air allows me to defeat the buoyancy of my weighted suit in the shallows and inspect the lower nooks and crannies in stillness. The boulder I have chosen is rich in red foliose seaweeds, Irish moss and clumps of sea lettuce. There is animal life, too– a cluster of pretty lightbulb sea squirts at the base and club-shaped colonial sea squirts lurking further up at a respectful distance. Higher still, patchy breadcrumb sponges are well-established and a couple of plump suberites carnosus grip tightly onto the rock.

Elspeth on a free dive in Cornwall.

Leaving the edge of the river, we join wriggling clouds of sand eels who scatter before us like lametta. Diving the seagrass always startles the sentinel worms who live there, who retract supernaturally fast and then appear again once the imagined threat I pose has passed. Today, between the blades, I see daisy anemones poking out. A beleaguered little hermit crab hauls past with a disproportionately large anemone on its back that seems to have the better end of the deal.

Swimming under the water, as far as my lungs will carry me over the seagrass, is such a pleasure. It's like a dream sequence flying through a flowery meadow, with many little beige snakelocks anemones nodding precariously on the grass. Often, this is how I spot the egg cases of small- spotted cat sharks, their parents, or a dozy nursehound eyeballing me sleepily from its bed.

Elspeth's sketch from the Seasearch Observer form she filled out for the dive.

Elspeth's sketch from the Seasearch Observer form she filled out for the dive.

Today holds a new surprise encounter though. A ribbon is weaving through the seagrass below me. It's a little juvenile snake pipefish. It pauses, freezes, effortlessly impersonating the grass. I try to do the same, but clumsily. Perhaps taking offence, it shoots off in another direction in a whiff of irritation and I let it go, a little dragon with pointed snout and glittering eyes that leaves a lasting impression on me beyond its entry on a form.

As Elspeth says "There is no such thing as an ordinary sea creature!"

Further information about Seasearch in Cornwall from Cornwall Wildlife Trust.

Photos and sketch all by Elspeth.

AUTHOR

Elspeth

Elspeth
Seasearch Volunteer & Free Diver