Two Masters projects plotting native and invading sealife of Falmouth Harbour

From a curious small-spotted cat shark and eels, to the less welcome invasive Pacific Oyster – two University of Plymouth MSc Marine Conservation students have been studying the underwater world of Falmouth Harbour for projects that are helping inform conservation and management in sensitive marine habitats.

Supported by Falmouth Harbour, Khianna Lee deployed Baited Remote Underwater Video Systems (BRUVS) to film and compare the diversity of marine life in artificial habitats of reef cubes and habitiles, with natural seagrass meadows and kelp forests.

Khianna recorded and painstakingly counted 545 individual animals across 18 families and four classes: the artificial habitats recorded the greatest abundance (including shoals of up to 169 sand smelt at a time on the reef cubes), while seagrass meadows supported the highest species richness and overall diversity.

“People see the surface of the sea, but very few get the incredible opportunity I’ve had of observing the complex ecosystems thriving beneath it,” says Khianna. “What I’ve found is that engineered structures can and are helping provide habitats for marine life (I even recorded a critically endangered European eel near the wall of habitiles).

“But my findings also reinforce the exceptional ecological value of established natural habitats and the importance of protecting and enhancing them – which I know Falmouth Harbour constantly strives to do.

“I hope this project piques people’s interest, especially among schoolchildren, about the incredible world beneath our seas and the need to take care of it.”

Meanwhile, Nadine Milner conducted an undersea project looking at the numbers of invasive Pacific Oysters within Falmouth Harbour – specifically in and around the Fal and Helford Special Area of Conservation (SAC) – and she worked closely with Falmouth Harbour and the Falmouth Marine Conservation group.

These invaders can create deep beds of oysters forming large reefs which can, if not controlled, encroach on important protected estuarine habitats. They are an increasing issue as regular attempts since 2019 at culling them have done little to dent their proliferation.

“I’ve been building a spatial risk map combining Pacific oyster density with their distance from sensitive habitats, including seagrass, kelp and maerl,” says Nadine. “Pacific oyster abundance has actually increased since culling started, and around 2 km of the SAC was identified as being potentially at risk.

“We may not be able to eradicate this invasive species from our waters – but the findings should help to focus future efforts to protect particularly important and sensitive habitats.

“I was so grateful for the support from Falmouth Harbour and the Falmouth Marine Conservation group who are making heroic efforts to control these invaders. It was fantastic to have the opportunity to present my research at the SAC Management Forum.”

Falmouth Harbour’s Environment Manager Vicki Spooner says, “We feel privileged to have supported Khianna and Nadine with research that is both academically robust and directly relevant to the management of our local marine environment.

“Their work gives us valuable evidence about the role of nature-inclusive infrastructure, the importance of natural habitats such as seagrass and where collaborative action on Pacific Oysters may be most effective. It also shows what can be achieved when students, researchers, volunteers and local organisations work together.”

Both projects will help inform future monitoring, partnership working and practical marine management. Falmouth Harbour hopes the students’ achievements will encourage further collaboration between academic institutions and organisations working to understand, protect and restore the marine environment.

University of Plymouth Professor of Marine Ecology Emma Sheehan, Director of its Centre for Marine Biology and Conservation Science (CMACS), says, “Khianna and Nadine’s work demonstrates how student-led research can make a meaningful contribution to marine conservation.

“Through our strong partnership with Falmouth Harbour, students have the opportunity to tackle real management issues, producing robust scientific evidence that helps guide the protection and sustainable management of these valuable coastal habitats.”

Organisations involved in the two research projects also include Natural England and Cornwall Council – with special thanks going to Chris Sharpe of Falmouth Marine Conservation’s Oyster Surveys, who has put vast amounts of effort into controlling local Pacific Oyster populations.

Falmouth Harbour will be sharing some of Khianna and Nadine’s videos and other images captured during their Masters’ projects. For more on these and other environmental, leisure and commercial work of Falmouth Harbour visit https://www.falmouthharbour.co.uk/   and for information on the University of Plymouth’s Centre for Marine Biology and Conservation Science (CMACS) visit https://www.plymouth.ac.uk/research/cmacs.