Er gwaetha’r tensiynau rheoli hyn, a gyda help Prosiect LIFE y Fôr-wennol Wridog, mae Ymddiriedolaeth Natur Gogledd Cymru wedi penderfynu parhau â thraddodiad Cemlyn o reolaeth ragweithiol a pharhau â’r gweithredu positif i wella cadernid môr-wenoliaid Cemlyn drwy ddarparu ‘rafftiau’ ar y môr-lyn. Mae’r rafftiau hyn yn efelychu cynefin nythu’r môr-wenoliaid ar yr esgair ac yn hafan ddiogel i gywion a rhieni fel ei gilydd – gan eu gwarchod rhag ysglyfaethwyr, aflonyddwch a lefelau’r dŵr yn newid. Mae’r rafftiau wedi’u hadeiladu o blastig wedi’i ailgylchu gyda haen o ro mân ar y top ac yn ddigon ysgafn i’w symud yn hawdd. Mae offer cynnal fertigol a thraws aelodau’n atal y gro mân rhag symud o gwmpas pan mae’n stormus ar y môr-lyn ac, i atal ysglyfaethwyr, mae ymylon uchel o bolycarbonad clir wedi cael eu hychwanegu. I osgoi defnydd gan wylanod Cemlyn ac adar ‘cynnar’ eraill nad oes cymaint o groeso iddynt, ni fydd staff YNGC yn angori’r rafftiau yn y môr-lyn nes ei bod yn amser i Fôr-wenoliaid y Gogledd a’r Môr-wenoliaid Cyffredin ddychwelyd. Bydd y defnydd o’r rafftiau’n cael ei fonitro drwy gydol 2017 gyda help y tîm o wirfoddolwyr sy’n cefnogi’r wardeniaid.     

Prif bwrpas y rafftiau yw helpu i greu cynefinoedd newydd a diogel i Fôr-wenoliaid y Gogledd a’r Môr-wenoliaid Cyffredin.  Er hynny, drwy helpu’r rhywogaethau hyn, ac yn enwedig y Fôr-Wennol Gyffredin, gobaith YNGC yw creu’r amodau sydd eu hangen ar gyfer dychweliad y Fôr-wennol Wridog, sydd â pherthynas yn aml (ac yn agos iawn yn achlysurol!) â’r Fôr-wennol Gyffredin.

‘O adeiladu ar eu cyfer, efallai y byddan nhw’n dod’.

Alison Brown, Swyddog Cymunedol y Môr-wennol gwridog

Today we have a blog post from Alison Brown, Roseate Tern Community Engagement Officer about the breeding terns and the hard working efforts of NWWT and volunteers at Cemlyn Bay in Wales.

You’ve probably seen the film and know the central theme that ‘if you build it, they will come’. One of the core aims of the Roseate Tern LIFE Project is for its partners to undertake enhanced management and to provide the conditions needed for a re-expansion of roseate terns in the UK and Republic of Ireland. For the Project’s participating sites where rosie’s still visit and breed; increasing their numbers and resilience presents many challenges. 

For sites recently abandoned by breeding roseate terns and where even sightings of the birds are few and far between, there is an increased urgency for pro-active management, habitat building and lateral thinking. At its’ Cemlyn Reserve, North Wales Wildlife Trust are building on a long tradition of active management and are providing new opportunities for terns to flourish and for the ‘rosies’ to come back to ‘mainland’ Wales.

Located on the north coast of Anglesey and on the eastern shores of the Irish Sea, Cemlyn is treasured for its remarkable scenery, its spectacular wildlife and its’ easy accessibility. It is this ease of access and popularity with all kinds of visitors that makes Cemlyn unique amongst all the sites being managed as part of the Roseate Tern LIFE Project. Surrounded by busy farms and farmland, the Cemlyn Reserve includes a large lagoon, separated from the sea by a spectacular, naturally-created shingle ridge. To the immediate east, the view is dominated by the Wylfa nuclear complex- currently the focus of proposals for a second nuclear power station. 

The easy accessibility of the Cemlyn Reserve, its’ lagoon, islands and nesting terns is not restricted to human visitors. The fields, wetland and scrub that surround the Reserve provide a rich mosaic of habitat for many wildlife species, including mammal predators which cross the shallow waters of the lagoon to reach the tern colonies on their low lying islands. Several species of raptors are also regularly seen in the locality and the larger gulls are also daily visitors. 

The Cemlyn Estate and farms are owned by the National Trust however, the lagoon and shingle ridge are managed by the North Wales Wildlife Trust who manage the Reserve and provide a summer warden service to help reduce disturbance, undertake monitoring and practical management as well as engaging with the visiting public.  Community engagement and supporting a wardening service at such an accessible and popular site is essential in protecting the interests of Cemlyn’s natural heritage.

While Cemlyn's shingle ridge in its' current form is geomorphologically young, being thrown up in storm 'events', the lagoon behind the shingle was effectively created in the twentieth century. Cemlyn holds a rather special place in the history of conservation, given that it was one of the first places to benefit from pro-active management solely for the benefit of its birds. The site's history as a wildlife site is tied to the story of Captain Vivian Hewitt, who came to northern Anglesey in the 1930s, settling in Bryn Aber, now a large house that dominates the western end of the Cemlyn Reserve. A wealthy eccentric, Cpt Hewitt's passion for birds led him to construct a dam and weir at Cemlyn, which replaced the tidal saltmarsh with a large and permanent lagoon intended as a refuge for wildfowl. His legacy and the creation of a stable body of water with small islands provide Cemlyn's terns with their nesting sites and a positive tradition of management that the North Wales Wildlife Trust continue today.

Maintaining Cemlyn’s lagoon islands and creating ‘space’ for breeding terns has presented a number of other challenges, not least being the ‘tension’ between overlapping European nature conservation ‘designations’.  Cemlyn’s shingle ridge and lagoon are designated as an SAC (Special Area of Conservation) and the lagoon itself is a priority feature, providing habitat for a number of rare species including the bryozoan Conopeum seurati, the lagoon cockle Cerastoderma glaucum, and the lagoonal mud-snail Ventrosia ventrosa.

Merely raising or expanding the lagoon islands for the benefit of the terns and other breeding birds is not a simple option given the potential for adverse effects on the SAC’s features of interest.  However, Cemlyn and the surrounding seas and coasts of Anglesey are also included within the Anglesey terns potential Special Protection Area and NWWT, as managers of the Site, must also maintain and ensure the integrity of Cemlyn’s ternery.

Despite these management tensions and with help from the Roseate Tern LIFE Project, North Wales Wildlife Trust have decided to continue Cemlyn’s tradition of pro-active management and to continue positive action to improve the resilience of Cemlyn’s terns by providing ‘rafts’ on the lagoon. These rafts replicate the terns’ shingle nesting habitat and provide a safer place for chicks and parents alike -protecting them from predators, disturbance and changing water levels.  The rafts are constructed from recycled plastic with a gravel tray on the top and light enough to be easily moved.  Vertical supports and cross members prevent gravel from moving around in choppy conditions on the lagoon and to deter predators, tall sides of clear polycarbonate have been added.  To avoid the rafts being used by Cemlyn’s gulls and other less welcome ‘early’ birds, NWWT staff won’t anchor the rafts on the lagoon until just before the return of the common and Arctic terns.  The use of the rafts will be monitored through 2017 with help from the team of volunteers who support the wardens.

In the first instance, the rafts are designed to help create new and safer habitat for common and Arctic terns.  However, by helping these species, and particularly the common tern, NWWT hope to build the conditions needed for the return of roseate tern which often associate (occasionally intimately!), with common tern.

‘If we build it, they might come.'