The part of Newport Wetlands National Nature Reserve we call Goldcliff Lagoons is primarily managed for the designated features laid out in the citation when Newport Wetlands was designated a Special Site for Scientific Interest, (SSSI). At Goldcliff Lagoons these include:
Another aim of the management at Goldcliff is to support the adjacent Severn Special Protection Area (SPA) by providing a safe un-disturbed high tide roost. Whenever the management of these features allow we also try to provide suitable habitat for migratory wading birds, flowering plants for pollinating insects and access for all to enjoy and appreciate nature.
We aim to achieve suitable habitat for the designated wintering waterfowl by having minimal vegetation on the lagoon islands to allow birds to roost, a short sward and low vegetation surrounding the lagoons to provide grazing for wigeon, but also so that waterfowl have clear vision of avian predators and cannot be ambushed by mammals. Water levels on Prior's lagoon would normally be lowered in September to provide a roosting area for black-tailed godwit. This water would be let on to Monk's and Bec lagoon to begin to raise the water levels to provide suitable habitat for dabbling ducks in the winter. The Prior's sluice is raised in October to begin to catch the winter rains, in this way Prior's provides habitat for diving duck in the winter and stores water that can be used to maintain water levels in Bec and Monk's lagoons during the critical period when wader chicks are feeding.
Habitat is maintained for breeding waders by ensuring minimal vegetation on the lagoon islands to allow waders, particularly avocet to nest and to prevent birds being ambushed by small mammals. Nesting conditions for lapwing and redshank are created on the grassland surrounding the lagoons by grazing with cattle. Cattle create the necessary tussocky sward for nesting waders and create habitat for insects by poaching the edges of the waterbodies and through their dung because they are not treated with Ivermectin. We try to keep cattle away from ground nesting birds to prevent them trampling nests.
The anti-predator fence is maintained to prevent foxes, otters and badgers eating the wader nests and chicks. We try to remove all the scrub within the anti-predator fence to deny an easy vantage point and roost for predatory birds like crows.
We aim to maintain water levels on Bec and Monk's lagoon so that there are feeding opportunities for wading chicks from mid-April to mid-July and that the water level never gets so high that it floods nests or so low that the mud dries out and kills the benthic invertebrates on which the waders feed. The water levels are held higher in Prior's to help us achieve the right levels on Bec and Monk's lagoons. We try to maintain the salinity of the Bec and Monk's lagoons at about fifteen parts per thousand to maximise the invertebrate biomass available to wading birds. Prior's is used as a fresh water supply to help maintain salinities on the other lagoons.
It's vitally important during the wintering and breeding seasons that disturbance is kept to a minimum. We do this primarily through managing visitor access but also by restricting our management work to between mid-July and the beginning of September and from mid-February to the beginning of March.
This is what we try to achieve but often many factors intervene for example, budgets, contractors, procurement, tenants, vandals etc. The biggest factor this year has been the unprecedented dry weather, with conditions like this it is not possible to keep the lagoons wet. Prior's lagoon is not big enough to hold the volume of fresh water required and there just hasn't been enough water on the rest of the reserve to make pumping into the lagoons viable. We can't winch open the tidal flaps and let the Severn in because the salinity is too high and the silt load clogs up the ditches and lagoons requiring mechanical removal.
Rainfall is a significant factor at Goldcliff Lagoons. All of the rain that falls within the 2.1km (1.3miles) of sea-wall, flood defences and secondary flood defences that en-circle the 28 hectares of Goldcliff Lagoons, can only drain out of that area through one 1.2m wide tidal flap. Before that it has to pass over a 54" wide wooden sluice-board. The tidal flap is closed 2 times a day by the high tide, so no water can drain out then. During periods of pro-longed heavy rain, the water levels in the lagoons can rise dramatically and take a long time to go down, regardless of how high the sluice boards are set. The recent work to "cast" the main ditches at Goldcliff, which connect all 3 lagoons and through which water has to flow to reach the tidal-flap outfall, will speed up the time it takes water to drain out of the lagoons. The dense Phragmites, "clogging up" the ditches greatly slowed down the flow of water.
In recent years we have not been able to exert the grazing pressure necessary to achieve the management objectives described above, we are working to change our grazing arrangements but in the meantime we took the opportunity of assistance from our Internal Drainage District team to cut the rank vegetation ready for the wintering waterbirds during the six weeks available. It's not something we could or would want to do every year, it's much better for plants and insects if the vegetation can be maintained through grazing alone.
Whilst we had use of the IDD excavator, we asked them to clean some of the reens. This is something that needs doing periodically for them to maintain the hydrological and ecological function. Ideally, we would clear sections every year with a de-weeding bucket on a two or three year rotation depending on how much phragmites was in the ditch. These ditches would need casting (the silt dug out) approximately every ten to fifteen years on rotation to maintain a mosaic of ditch habitat. Unfortunately, we don't always have the budget or an available contractor to do the work.
Whilst casting the reens the IDD noticed the reens that had been de-weeded by a contractor two years ago hadn't been weeded properly. As a result, we asked them to cast all the ditches for three reasons. The unprecedented drought meant that a lot of the reens were already dry, so casting them now had a minimal impact on wildlife. Secondly some of the reens had got so overgrown that they needed doing soon and I couldn't guarantee having the money or the staff/contractors next year. Thirdly the IDD are highly skilled and represent much better value for money than if we hired in contractors.
Mireland Pill Reen, the reen which runs next to the main visitor route between the 1st and 2nd hides, is managed by the NRW's Internal Drainage District (IDD). They manage it with the aim of preventing flooding, but also to supply water, diverted from the Monk's Ditch just before it goes into the sea, to farmland to the east. The sea defences and flood defences along Goldcliff Pill are managed by NRW with the aim of allowing the defences to be inspected twice a year and to prevent the growth of trees and scrub which could damage the defences. This is achieved by mowing the defences once a year. This is done in July or August and we encourage them to do this as late as possible, primarily to benefit shrill carder bees.
Tom Dalrymple and Kevin Boina M'Koubou Dupé