Oysters Return to the Haven

In Welsh and English

Prosiect adfer wystrys yn mynd ati i gyfoethogi Dyfrffordd y Daugleddau

Mae prosiect newydd cyffrous ar y gweill i adfer y boblogaeth o wystrys brodorol a fu unwaith yn doreithiog yn Nyfrffordd Aberdaugleddau a, thrwy wneud hynny, bydd yn gwella cyflwr Ardal Cadwraeth Arbennig (ACA) Forol Sir Benfro.

Mae’r gwaith hwn yn cael ei gynnal mewn partneriaeth â Phrifysgol Bangor, Swyddog ACA Forol Sir Benfro, a Tethys Oysters ym Mae Angle, ac mae’n rhan o Elfen Carbon Glas y Rhaglen Arfordir Gwyllt! Tirweddau Cynaliadwy, Lleoedd Cynaliadwy yn Awdurdod Parc Cenedlaethol Arfordir Penfro, a ariennir gan Lywodraeth Cymru ac a gydlynir gan Tirweddau Cymru.

Dywedodd James Parkin, Cyfarwyddwr Natur a Thwristiaeth Awdurdod Parc Cenedlaethol Arfordir Penfro: “Mae 25% o dirwedd Cymru yn dirweddau dynodedig, fel Parc Cenedlaethol Arfordir Penfro, sy’n golygu eu bod yn chwarae rhan hollbwysig yn y gwaith o helpu natur i adfer.

“Mae’r Gronfa Tirweddau Cynaliadwy, Lleoedd Cynaliadwy, yn cael effaith sylweddol ar ein gallu i greu amgylchedd cynaliadwy a chadarn ar gyfer cenedlaethau’r dyfodol.”

Ers i’r prosiect ddechrau ym mis Tachwedd 2023, mae stoc mag Ostrea edulis wedi cael ei gasglu o Fae Angle a Burton Ferry a’i gludo i Brifysgol Bangor, gyda’r nod o’i fagu a’i ddychwelyd i Ddyfrffordd Aberdaugleddau i roi hwb i boblogaethau presennol.

Disgwylir y bydd hyd at 200,000 o silod wystrys brodorol yn cael eu cynhyrchu, ond gallai’r niferoedd fod yn llawer mwy.

Esboniodd Sarah Mellor, Swyddog Bioamrywiaeth Awdurdod y Parc Cenedlaethol: “Mae poblogaethau wystrys Prydain wedi dirywio’n arw dros y degawdau, o ganlyniad i golli cynefinoedd, llygredd, gor-gynaeafu a chlefydau. Mae goblygiadau hyn i iechyd ein hamgylchedd morol yn sylweddol. Yn ogystal â bod yn hidlwyr bwyd sy’n puro’r dŵr o’u cwmpas, mae wystrys hefyd yn storio carbon, ac mae eu riffiau hefyd chwarae rhan bwysig o ran meithrin bioamrywiaeth drwy ddarparu bwyd, lloches a gwarchodaeth i amrywiaeth eang o fywyd morol.”

Ar hyn o bryd, ychydig iawn o gyfleusterau meithrin sy’n gallu darparu wystrys brodorol i’w hadfer. Mae’r wystrys brodorol sydd wedi cael eu cyflwyno i’r Ddyfrffordd hyd yma wedi cael eu magu ym Mae Morecambe. Mae statws Dyfrffordd Aberdaugleddau fel ardal Bonamia (clefyd parasitig) hefyd yn gosod cyfyngiadau ychwanegol ar symud wystrys.

Mae rhai pobl o’r farn y gallai’r hen wystrys brodorol sydd yma fod â rhywfaint o ymwrthedd i glefyd Bonamia. Dyma pam – yn ogystal â’r awydd i ddiogelu gwneuthuriad genynnol poblogaethau lleol, a allai hefyd ddarparu cadernid ychwanegol – y mae adfer gan ddefnyddio stoc frodorol yn opsiwn mor ddeniadol.

Yn dilyn protocolau bioddiogelwch a chyfnod byr o gwarantin, mae’r llwyth cyntaf o tua 40 o wystrys wedi dechrau’r broses gyflyru i silio yn eu meithrinfa dros dro. Bydd yr wystrys sy’n weddill yn cael eu cyflyru i silio yn ystod gwanwyn a dechrau haf 2024.

Capsiwn: Bydd y prosiect adfer yn rhoi hwb angenrheidiol i boblogaethau gwasgaredig o wystrys brodorol yn Nyfrffordd Aberdaugleddau.

A project is underway to restore the once-abundant population of native oysters within the Milford Haven Waterway and so improve the condition of the Pembrokeshire Marine Special Area of Conservation (SAC).

This work is being carried out as part of the Blue Carbon Strand of the Pembrokeshire Coast National Park Authority’s Wild Coast Sustainable Landscapes, Sustainable Places programme, funded by the Welsh Government, in partnership with Bangor University, the SAC officer and Tethys Oysters in Angle Bay, co-ordinated by Tirweddau Cymru Landscapes Wales.

The director of nature and tourism at the Pembrokeshire Coast National Park Authority, James Parkin, said: “Designated landscapes, such as the Pembrokeshire Coast National Park, account for 25 per cent of the Welsh landscape, which means they have a vital role in helping nature to recover.

“The Sustainable Landscapes, Sustainable Places Landscapes fund is having a significant impact on our ability to create a sustainable and resilient environment for future generations.”

Since the project started in November 2023, Ostrea edulis broodstock have been collected from Angle Bay and Burton Ferry and transported to Bangor University, with the aim of rearing them and returning them to the Milford Haven Waterway to boost existing populations.

It is expected that up to 200,000 native oyster spat may be produced, but numbers could be significantly more.

National Park Authority biodiversity officer Sarah Mellor said: “Native British oyster populations have declined dramatically over the decades, as a result of habitat loss, pollution, over-harvesting and disease. This has significant implications for the health of our marine environment. As well as being filter feeders that actively purify the surrounding water, oysters also store carbon, and their reefs also play an important role in fostering biodiversity by providing food, shelter and protection for a wide variety of marine life.”

There are few nursery facilities that can provide native oysters for restoration. To date, native oysters introduced to the waterway have been reared in Morecambe Bay. The status of the Milford Haven Waterway as a bonamia (a parasitic disease) area also places additional restrictions on the movement of oysters.

There is a view that existing old native oysters may have some resistance to bonamia. This, and the desire to protect the genetic make-up of local populations, which may also provide additional resilience, is why restoration using indigenous stock is so attractive.

Following biosecurity protocols and a brief period of quarantine, the first batch of approximately 40 oysters have started conditioning to spawn in their temporary nursery. The remaining oysters will be conditioned to spawn in the spring and early summer of 2024.