{{Short description|Marshland in Anglesey, Wales}} {{Use dmy dates|date=June 2015}} {{Use British English|date=June 2015}} [[File:The Malltraeth Marsh flatlands - geograph.org.uk - 877749.jpg|thumb|right|250px|Malltraeth Marsh flatlands near the village of Pentre Berw]]
'''Malltraeth Marsh''' (also spelled as '''Malldraeth'''; {{langx|cy|'''Cors Malltraeth'''}} or {{langx|cy|'''Cors Ddyga'''|label=none}}) is a large marsh area in Anglesey, North Wales, north-east of Malltraeth village, along the flatlands of Trefdraeth, Bodorgan, Llangristiolus and south of Cefn Cwmwd, Rhostrehwfa. It was reclaimed from estuarine marshes after the construction of the Malltraeth Cob (dyke), a {{convert|1|mi}} long embankment,<ref name="malltraeth.com">{{cite web|url=http://malltraeth.com/|title=Welcome to the Malltraeth Ymlaen Frontpage|work=malltraeth.com|accessdate=14 August 2011}}</ref> and the subsequent canalisation in 1824 of the Afon Cefni.<ref name="angleseynature.co.ukSSSI">{{cite web|url=http://angleseynature.co.uk/webmaps/malltraeth.html|title=Malltreath Marsh/Cors Ddyga SSSI|work=angleseynature.co.uk|accessdate=14 August 2011}}</ref>
The name Malltraeth comes from ''mall'' ('bad'), and ''traeth'' ('sandy shore').<ref name="Carlisle1811">{{cite book|last=Carlisle|first=Nicholas|title=A topographical dictionary of ... Wales, a continuation of the topography of the United Kingdom of Great Britain and Ireland|url=https://books.google.com/books?id=ATITAAAAQAAJ&pg=PT446|accessdate=13 August 2011|edition=Now in the public domain.|year=1811|pages=446–}}</ref> The marsh measures {{convert|1366.5|ha}} in area. The area is recognised as a Site of Special Scientific Interest (SSSI), and has a range of reedbeds, marshes, wet grassland and small pools/lakes.<ref name="rspb.org.uk"/>
==History== thumb|right|250px|Malltraeth Marsh and the Cefni flood embankment
In the Middle Ages the '''Malltraeth estuary''' was tidal, stretching as far inland as Llangefni and Ceint.<ref>{{Citation|url=https://books.google.com/books?id=i1N-DwAAQBAJ&dq=Rhosyr+cantref&pg=PA8 |last=Aris |first=Mary |title=Rhosyr: Its History and Topography in the Age of the Welsh Princes |publisher=Matador |year=2019 |pages=8–9 |isbn=978-1789016-673 }}</ref>
In 1790, an act of Parliament was obtained for more effectually embanking the marshes called Malltraeth and Corsddeuga, under the provisions of which {{convert|230|acre|order=flip}} were allotted to the several proprietors of land in the parish of Llangaffo.<ref name="Genuki">{{cite web|url=http://www.genuki.org.uk/big/wal/AGY/Llangaffo/index.html|title=LLANGAFFO|publisher=Genuki.org|accessdate=13 August 2011}}</ref> The {{convert|4000|acre|order=flip}} of reclaimed alluvium at the mouth of the River Cefni subsequently underwent considerable improvements in the late-18th century and early-19th century with the introduction of embankments and flood mitigation measures.<ref name="CloutMunton2007">{{cite book|last1=Clout|first1=Hugh D.|last2=Munton|first2=R. J. C.|title=Contemporary rural geographies: land, property, and resources in Britain : essays in honour of Richard Munton|url=https://books.google.com/books?id=AkEDI2w5CBsC&pg=PA31|accessdate=14 August 2011|year=2007|publisher=Routledge|isbn=978-0-415-43183-5|page=31}}</ref> During World War I, further improvements were made due to the concerns of farmers. However the reclamation became neglected and by the end of the war, it had fallen into a bad state and was subject to numerous heated conflicts between the drainage engineer, the CWAEC, and the underfunded catchment board managing the drainage of the marsh.<ref name="CloutMunton2007"/> Bitter disputes over the marsh reached a climax with the chairman resigning from the Malltraeth Marsh and Cors Ddyga subcommittee in March 1942 and unusually high rainfall during the harvest in the following year devastating most of the cereal crops in the area.<ref name="CloutMunton2007"/> Due to pressure from local farmers, Lord Anglesey met with Robert Hudson and Megan Lloyd George in 1944 to outline ideas for improving the local habitat.<ref name="CloutMunton2007"/> Some £100,000 was allocated to developing what was about 50% derelict marsh during the war and by 1947, £147,000 had been spent on the scheme.<ref name="CloutMunton2007"/> center|600px|thumb|The marsh near Morfa Brennin
==Geography== thumb|right|250px|Pool alongside the railway line on the Malltraeth Marsh thumb|right|250px|View across Malltraeth Marsh towards Pen-y-Bont Farm
Located in the cwmwd of Malltraeth,<ref name="Carlisle1811" /> Cors Malltraeth Marsh is on the west side of the Afon Cefni valley which crosses Anglesey parallel to the Menai Strait, approximately {{convert|4|mi}} to the north-west.<ref name="Woodward1876">{{cite book|last=Woodward|first=Henry|title=Geological It remains good grazing land compared with Cors Ddyga. landmagazine|url=https://books.google.com/books?id=8DcFAAAAYAAJ&pg=PA134|accessdate=13 August 2011|edition=Now in the public domain.|year=1876|publisher=Cambridge University Press|pages=134–}}</ref> The habitat of Cors Ddyga on the east side of Afon Cefni has been reverted to wetlands and reeds. The wetland reserve is officially called RSPB Cors Ddyga. It consists of marshy grasslands, lakes, pools, fossiliferous coal and shales.<ref name=Site>{{Cite web|url=http://angleseynature.co.uk/webmaps/malltraethmarshsms.html|title=Malltraeth Marsh and Cors Ddyga, Site of Special Scientific Interest|accessdate=15 August 2011|publisher= Countryside Council for Wales}}</ref>
The geology underlying both marshes, Cors Malltraeth and Cors Ddyga, is characterized by Carboniferous Limestone, millstone grit, soft coal measures shales, sandstone, coal seams, and Permian strata.<ref name="SOCIETY1876">{{cite book|author=The Assistant-Secretary of the Geological Society |title=The Quarterly Journal of the Geological Society of London|url=https://books.google.com/books?id=iaMEAAAAQAAJ&pg=RA1-PA120|accessdate=13 August 2011|edition=Now in the public domain.|year=1876|pages=120–}}</ref> The Afon Cefni valley is {{convert|9|mi}} long and runs almost exactly parallel to the valley of the Menai Strait.
Malltraeth Marsh is a wide and perfectly flat expanse of reedy pasture. An embanked tidal river runs through its midst, opening to Malltraeth Sands, {{convert|0.5|mi}} to the southwest. A short tunnel, the first in Anglesey, pierces the low hills which extend along the west side of Malltraeth Marsh before reaching Bodorgan railway station.<ref name="Baddeley1884">{{cite book|last=Baddeley|first=Mounftord John Byrde|title=North Wales (part 1) Chester, Rhyl, Llandudno, Bangor etc.|url=https://books.google.com/books?id=F_sVAAAAYAAJ&pg=PA95|accessdate=13 August 2011|edition=Now in the public domain.|year=1884|publisher=Dulau & Co.|pages=95–}}</ref> Above Malltraeth lies the extensive common land of the marsh, which is bounded on the north-west by the parishes of Llangadwaladr, Trefdraeth, and Llangristiolus; on the northeast by Llangefni and Llanffinan. Cors Ddyga ("Tygai's marsh") lies in the commote of Rhosyr. It is on the east side of the Afon Cefni River or Afon Fawr Llanfihangel-y-Ceifiog, Llanidan, Llangaffo, Llangeinwen, and Newborough.<ref name="Carlisle1811" />
==Vegetation== The vegetation reported from the Malltraeth Marshand and Cors Ddyga consist of reed canary-grass, water-plantain, branched bur-reed, club rush and reed sweet-grass. Spiked water-milfoil, blunt-leaved pondweed, horned pondweed are also reported in the marsh land, apart from rare species of flowering rush, water-violet and marsh stitchwort.<ref name=Site/>
==Fauna== European water voles inhabit the marsh. Birds such as northern lapwing, Eurasian curlew, common redshank and common snipe are reported from the lowland wet grassland. Eurasian teal, northern shoveller, gadwall and common pochard occupy the open water.<ref name=Site/> Other birds recorded are Eurasian bittern and grey heron.<ref name=Site/> Invertebrates include water beetles (''Hydrochus brevis'') and hairy dragonflies.
==Conservation== thumb|right|Reclaimed farmland on the western edge of the Malltraeth Marsh
Malltraeth Marsh and Cors Ddyga is a Site of Special Scientific Interest (SSSI). The marshes are notable for their breeding bird community, lowland damp grassland, reedbeds, the threatened habitat of wet meadows, and the botanical importance of their ditches and watercourses.<ref name="angleseynature.co.ukSH440710 ">{{cite web|url=http://angleseynature.co.uk/webmaps/malltraethmarshdesc.htm|title=Anglesey Malltraeth Marsh / Cors Ddyga National Grid reference: SH440710 |work=angleseynature.co.uk|accessdate=14 August 2011}}</ref> A Royal Society for the Protection of Birds reserve is situated in the north-east corner of the SSSI.<ref name="rspb.org.uk">{{cite web|url=http://www.rspb.org.uk/reserves/guide/m/malltraethmarsh/index.aspx|title=Malltraeth Marsh|work=rspb.org.uk|accessdate=14 August 2011}}</ref>
Management options undertaken to conserve the marshland consists of: maintaining water levels by proper upkeep of clay-lined ditches to conserve flora and fauna; maintaining an exclusive swamp area to breed bittern; creation of shallow water ditches along old water courses to drain large land areas where waders can feed; establishing water control structures on secondary drains to maintain high ground water table during the spring season; control of introduced invasive plant species such as fairy fern, Australian stonecrop and Himalayan balsam; reduce risk of predation (by predators such as crows and minks) of birds by constant conservation and preservation of hedges; encouraging grazing during the winter season and reducing it during summer to attract ground nestling birds, and controlled agricultural management to provide nestling sites for waders.<ref name=Site/>
==References== {{Reflist|2}}
{{coord|53.216|-4.333|display=title}}
Category:Llanfihangel Ysgeifiog Category:Llangristiolus Category:Marshes of Anglesey Category:Nature reserves in Anglesey Category:Sites of Special Scientific Interest in West Gwynedd Category:Royal Society for the Protection of Birds reserves in Wales