A seaweed search is not an everyday event at Porthcurnick beach, but on the last low spring tide in June, a group of wildlife enthusiasts could be seen wading through rockpools along the shore below Pednvadan Point. They were looking for just 14 of the 650 species of seaweed that can be found around the British Isles.
By Chris Townsend.
The Big Seaweed Search is a national project run by the Natural History Museum and Marine Conservation Society. Its aim is to get people interested in the wonderful seaweeds on our shores, and in doing so contribute to some real scientific research. The plan is to monitor 14 target species around UK coasts; evidence shows that seaweeds may be affected by three key environmental changes: sea surface temperature rise, ocean acidification and the spread of non-native species.
Many people are new to seaweeds and names can be tricky. Harpoon Weed, Hook Weed, Wakame or Wireweed? These four non-native project species may become invasive, having an impact on local ecosystems. Sugar Kelp, Bladder Wrack and Thong Weed are three of the eight cool water seaweeds targeted – possibly affected by warming seas. Chalky red seaweeds can become corroded by more acidic water; project species are Calcified Crusts and Coral Weeds. On the beach our group had a close look at named specimens in trays of sea water and got to grips with identifying the 14 seaweeds before their survey.
National Trust Rangers had earlier marked out our five metre wide transect, from the upper shore to the low tide mark. We plan to do annual surveys here (if not more frequently) so that changes are monitored. Starting at the sea’s edge, the presence or absence of the 14 seaweeds was noted as we walked up the shore. Six of the eight cold water seaweeds were found, including two little Channel Wrack plants high on the shore – distribution ‘sparse’! We were surprised to find Wireweed and Harpoon Weed growing abundantly in most rock pools. The Calcified Crusts and Coral Weeds grew on all the rocks underneath Serrated Wrack. We’d found 10 of the 14 species, and will record our findings at www.nhm.ac.uk/seaweeds
Seaweed pressings, seaweed foraging, the Fal’s maerl and the ecological and economic importance of seaweeds are fascinating aspects of this great group of plants. Watch this space – Roseland’s Seaweed Group might get together again for more surveys and seaweed events! Look for the local National Trust events at www.roselandonline.co.uk and Wild Roseland events at www.wildroseland.org
Photography by Chris Townsend, Steve Sudworth.
Upcoming Wild Roseland Walks and Talks – dates for your diary
Note that all events are free but a small donation of £3 would be welcomed.
– Sue Sayer, Cornwall Seal Group.
Thursday 21st September 2017, 7.00pm, Philleigh Community Centre.
Grey seals are one of the world’s rarest seal species, making our populations globally significant. This talk covers all aspects of the life of grey seals, their habitat and behaviour, and is presented by Sue Sayer, founder of Cornwall Seal Group.
Cirl Bunting Reintroduction Project News
We had some great news to celebrate in July, regarding our oldest and last, ringed, reintroduced male Cirl, who lives at Churchtown Farm in St Just. He turned the grand old age of six years, which for a Cirl bunting is a considerable age given the trials of life that these small farmland passerines experience. In spring 2011, this little bird was taken as an early season nestling with his siblings, from Agatha Christie’s Greenway House estate near Brixham in Devon; to be hand reared in the Rosleand before release from Tregassick. Like many others, he survived this unusual start to his life and somehow made his own way west to St Just, where at the age of one he established the breeding territory that he has held ever since. This little bird’s strength of character and determination to survive are truly remarkable. We hope he has passed on his exceptional genes to many offspring.
Edited by Sarah Vandome
Chris Townsend, Steve Sudworth.
References and links
Natural History Museum, The Big Seaweed Search:
Enjoy more Roseland wildlife and landscapes – visit Sarah Vandome’s Heart of Roseland Facebook feature:
Wild Roseland is a group of volunteers who care passionately about looking after the nature and landscape of the Roseland peninsula in south Cornwall. Through a number of initiatives and projects, the aim is to inspire and enhance the conservation of this special place for all.