Article for Cornwall Today Magazine by David Chapman
Only a mile or so from the heart of Falmouth there is a nature reserve offering an oasis of calm and tranquillity, an escape from the busy life of the town but it hasn’t always been this way.
The history of Swanpool is interesting and varied but there are a few moments which have really helped to shape what we see today. The first and possibly most significant event probably happened a few thousand years ago, though it is difficult to be precise. We know that during the last Ice Age, say about 10,000 years ago, the sea wouldn’t have come close to Swanpool but as the ice melted and the sea level rose the shape of our current coastline was gradually formed.
As this was happening a great deal of sediment was shifted towards the land by the effects of the sea. In the gap between Pennance Point and Swanpool Point shingle and sand was deposited in the sheltered bay. This became the beach that we see today and the whole process resulted in the river, flowing through Swanvale, becoming trapped.
You might recognise a similarity between this story and that at other sites around the south west of England. Loe Bar near Porthleven was formed in exactly the same way, as were Slapton Sands in Devon and Portland Beach in Dorset, to name but a few. In a way it is what has happened since that time which has helped to determine the uniqueness of each of these locations as we see them today.
Industry became prevalent in the area from the end of the 18th century. In 1790 Swanpool mine began to expand its operations on the western side of the lake and even mined the lode underneath the lake. Sediment cores taken from beneath the lake have identified the change in sediment types which occurred in association with mining at this time.
Further industrial development took place in 1852 when a lead mine was opened behind the beach and a tunnel was cut to Pennance Point where the fumes were released through a large chimney stack. Pennance Point is still referred to today as ‘The Stack’. Apart from finding lead and silver the mine, known rather ominously as Wheal Swamp-All, also produced arsenic as a by-product. Some of the arsenic was bound for America where it was used to tackle a pest in the cotton fields known as the boll weevil. The beach was used to ship the goods out and it is possible to see many old photographs showing how the area used to look in the building by the crazy golf course in the car park during the summer.
When the valley became dammed permanently by the beach it was transformed from a tidal muddy creek to a freshwater lake. It remained this way until 1862 when a culvert was created allowing water to flow from the lake into the sea. It is likely that this was cut to reduce the water level in the pool and the amount of water in area of the mine operations but it had a huge impact on the lake.
Prior to this when the lake was full of water it was about three metres deeper than it is today and the surface area of the water was three times greater. Water would only have been able to drain from the lake by percolating through the beach and crucially sea water would rarely have got into the lake.
All this changed when the culvert was created. Not only was the level of the lake reduced but it was also kept at a more constant height. Most significantly sea water could now enter the lake on all but the smallest high tides. We weren’t to know at the time that this would lead to this lake becoming one of the most significant brackish lagoons in Britain.
The end of the mining era changed the face of the area once more. Not much is left of that time today but one thing that does remain is the car park. This was constructed by American soldiers at the end of World War II on marshy ground using spoil heaps left behind by the mine. The Americans with their earth movers were asked by Falmouth Borough Council to level the ground, no spoil was taken away, that is why the car park is higher than the road.
Since that time the lake has been used as a recreational area for the residents of Falmouth. Most notably it was a popular boating lake and though boating no longer takes place it is still used by Falmouth Model Boat Club. The edges of the lake were relatively barren and it is interesting to look through old photographs to see how much the vegetation has grown up in the last few decades.
We are now left with a lake which is fed by six small rivers from its northern end and which is regularly flooded by saltwater at its southern end. This has created quite a unique ecosystem and Swanpool has been classified as one of the 11 most important brackish lagoons in Britain. One of the main reasons for this classification was only discovered relatively recently. Naturalists from the Natural History Museum surveyed the site and found something very unusual.
Growing in the lake, attached to stones and the stems of vegetation is a very rare animal, a primitive species belonging to the phylum of Bryozoans. Bryozoans are known commonly as ‘moss animals’ because they are very small, often only 0.5mm long and grow in mats just like mosses. The particular species which is found in Swanpool is found nowhere else in the UK and is known as the ‘trembling sea mat’ (Victorella pavida).
This creature grows in colonies and each animal uses a crown of tiny tentacles to catch food which drifts by in the current, a process known as filter feeding. This is a species which we still know relatively little about but it is clear that the brackish conditions at Swanpool are suitable for it. Given its rarity it should come as no surprise to learn that it is protected by law and soon after this species was found Swanpool was designated as a Site of Special Scientific Interest (SSSI) in 1995.
Swanpool and the beach are under the aegis of Cornwall Council but are leased to Peter Lochrie who runs the cafe, car park, crazy golf course and nature reserve. Peter is passionate about the lake and its wildlife, that much soon became evident to me as we chatted about the management of the area in his office, which overlooks the lake from the car park.
The designation of the site as a SSSI brought Swanpool to the wider attention of the conservation community but it just confirmed what Peter and most locals already knew; that Swanpool had become very important as a breathing space for nature as well as people. A management forum was formed which involves Peter, Cornwall Council, Natural England and representatives of local groups. This forum is very much still a part of the decision making for the future of the lake and surrounding area.
Regular work undertaken around the reserve includes coppicing of willow and alder to encourage the re-growth of reeds around the fringe of the lake. Reeds are very important to the many species of birds which seek refuge here. Litter picks are undertaken regularly to help keep the place looking respectable and encourage a greater respect for the environment amongst casual visitors.
Litter doesn’t just come in the form of plastic bags and wrappers from convenience foods. Another form of littering comes from the dumping of garden waste and this can lead to more significant problems. In amongst garden waste can be the seeds and rhizomes of non-native, sometimes invasive, species. Japanese Knotweed has been found on site and because of the sensitivity of the area this has to be dealt with very carefully. Cornwall Council has adopted the strategy of cutting the stems and injecting poison to deal with this difficult issue.
Issues relating to non-native species don’t stop with garden plants. At Swanpool, in the past, people have even discarded unwanted terrapins into the lake. Terrapins are not native to Britain so releasing them in this way is illegal but more importantly it is impossible for us to tell what damage they might do to our native species. There are plenty of examples of us causing wildlife catastrophes by releasing non-native species carelessly into the environment, one example is the release of mink from fur farms which has caused the extinction of the water vole in Cornwall.
When I met Peter a few weeks ago he had just heard some good news. Above Swanvale a new housing development is being built by Wainhomes and as part of the agreement to build here they have agreed to donate £10,000 to the Swanpool Management Forum and Peter was about to meet with other forum representatives to discuss how this would be spent. The plan is to build a boardwalk, viewing and feeding platform with interpretation boards and seating on the western side of the lake so that people can get access safely into this special wetland habitat.
Peter is particularly keen on the idea because school parties regularly come down to learn about wildlife at Swanpool and it is now a regular part of the curriculum for local primary children. To be able to provide a boardwalk and interpretation area will enrich this experience and enable the children to see more whilst being safe from traffic on the road.
It is interesting to reflect on the history of a location like Swanpool partly because it makes us realise that nothing is fixed. Swanpool will continue to change and there is no getting around that. What I hope will happen is that the future changes will be managed so that wildlife can adapt and the local community can continue to enjoy this beautiful place. Looking at what is happening here I feel confident that it will do just that.
Swanpool is south of the centre of Falmouth at SW 803 313. It is easily accessible on foot from the train station. There is a car park which is free in winter but from 1st April to 30th September there is a £2 charge. This allows you to park for the whole day and even entitles you to one free cup of tea in the café and you can come and go as you please all day.It is possible to walk around the entire lake using the path along the road and a minor road. At the car park there are toilets and a cafe for refreshments. Don’t forget to have a look at the old photographs of the area in the information building in the car park
Swans at Swanpool
Mute swans have a long association with the lake and are the reason for its name. In years gone by there were many pairs nesting here but in recent times there has been just the one. The male swan, or cob, which has lived here for the last 10 years, or so, had a settled relationship with a single female, or pen. He was quite aggressive in his defence of their territory, so much so that no other swans were tolerated in the breeding season.
Last year something very sad happened. The pen was taken by a fox. When a male swan is left alone he can respond in many different ways but in this case he disappeared for a few days, taking in a trip to the Helford River, and came back with a new mate. They are now to be found at the northern end of the lake.
Strangely the old cob now seems to be tolerating a new pair of swans which have taken up residence at the southern end of the lake.
To try to help the swans, in 2007, two floating islands were constructed on the lake to encourage them to nest in safety. Funding for these islands came from the ‘Awards for All’ community grant scheme which is part of the National Lottery Fund.Another issue which has caused problems for the swans is that of discarded fishing line and hooks. In 2009 one of the cygnets was found unwell. After monitoring the situation this bird was taken to a wildlife hospital in Somerset called West Hatch. Here it was discovered that the swan has swallowed a fishing line and that the hook was embedded in its throat. Fortunately the swan recovered with the help of an operation and all was well. In response to this the forum has established a permit system for fishermen who must now follow a code of conduct to try to prevent this happening again.