Real climate change effects on Anglesey : 1. the natural world

Ecosystems / Biodiversity

Climate change is already affecting our natural world : rising temperatures, changing rainfall regimes and increasing storminess are conspiring to change the growth regimes of plants, the interaction between insects and plants, the interaction between mammals and birds and their food supplies.

Nature runs on a carefully coordinated schedule : grazing insects, animals and birds have young when there is an abundant food supply from growing plants: predatory insects, animals and birds have young when there is an abundant food supply from their victims who probably depend on plants ……. interference with the timing of any stage causes this intricate food web to collapse ……. leading to chaos in the natural world – but also in the agricultural world.

Species are on the move – polewards and upwards- to maintain their ecological range “Global meta-analyses documented significant range shifts averaging 6.1 km per decade towards the poles (or metres per decade upward), and significant mean advancement of spring events by 2.3 days per decade”. [research paper in ‘Nature’] Others research discuss discontinuities in the food web [classic study on oak trees ,blue tits and caterpillars] and possibly evolutionary trends as adaptation

We are seeing new species appearing, existing species changing their ranges, some disappearing.

Anglesey has many endangered species and a number of priority habitats, including lowland and coastal heath, sandy beaches, cliffs, lakes, reedbeds, fens, broadleaved woodlands, ancient and species-rich hedgerows, ponds and flower-rich road verges. The nationally and internationally important west coast sand dunes are some of the most extensive sand dunes in Wales.

State of Nature 2019 report details the risks face and impacts already noticed and whilst agriculture and land use change get much of the blame, climate change is undoubtedly a major factor. The report, summarised by the BBC says

  • Of the 6,500 species found in Wales, 523 (8%) were threatened with extinction from Great Britain
  • There is enough data on 3,902 of the species to assess their risk of disappearing specifically from Wales
  • A total of 666 (17%) were threatened with extinction from Wales, with another 73 having been lost already.

Notable species include several threatened birds, mammals, insects and plants.

  • The Roseate Tern (Britain’s rarest breeding tern) and Bittern historically bred on Anglesey, but their return as breeders remains uncertain for the future. Enhancement and safeguarding of habitat is therefore imperative to ensure their continued presence on the Island. Climate change affecting water quality in wetlands and fens could affect the bitterns. Roseate terns will be affected by sea level and storminess damaging their nesting sites.
  • The Otter returned to Anglesey in the 1990s, following an absence of 20 years, helped by river water quality improvements. Increased storms leading to soil erosion, nutrient leaching or slurry runoff could reverse these improvements in water quality.
  • Red Squirrels are now widespread on Anglesey, helped by an effective and ongoing reintroduction programme over the last 20 years or so. These could be threatened by changing woodland conditions.
Red squirrel
Red squirrel
  • Large areas of sea around Anglesey are part of a Special Protection Area for the Harbour Porpoise. This species can be seen off the north coast in particular.
  • The rare Marsh Fritillary butterfly can also be found here. Anglesey used to be one of the European strongholds for this species, but now only small numbers remain.
  • The island has a wealth of rare plants, such as our county flower, the Spotted Rock Rose. The South Stack Fleawort is only found at South Stack, and nowhere else in the world. Other plants that are in decline on the island include Chamomile, Pale Dog Violet and Lesser-Butterfly Orchid.
  • Mammals like the red squirrel and water vole, birds like the curlew and plants such as the fen orchid could be squeezed out by loss of habitat and pollution. As many as one in six species are at risk of disappearing from Wales in the coming decades according to a recent study.

habitats are also threatened :

  • Fens on Anglesey are low in nutrients, which lead to a wider range of plants compared to nutrient-rich conditions. The rare calcareous (lime-rich) fens are the second largest in area in Britain and hold wildlife which has become rarer as the extent of this habitat has declined for many years. Species that can be found in this habitat include black bog rush, various orchids, insectivorous plants, dragonflies and butterflies. Also to be found here are rare blood-sucking medicinal leeches, as well as newts, frogs, toads and many birds, including the rare grasshopper warbler. Historically these wetlands used to stretch from Malltraeth to Lligwy, but today fens are centered at the key sites of Cors Goch, Cors Erddeiniog National Nature Reserves, and Cors Bodeillio. Increased rainfall and in particular, storms could lead to soil erosion and nutrient leaching bringing large quantities of nutrient into these fens, destroying their main characteristic – the low nutrient status.
Cors Ddyga - climate change threatens this by both sediment and nutrients from eroding farmland and by salinsation from sea level rise
Cors Ddyga – climate change threatens this by both sediment and nutrients from eroding farmland and by salinsation from sea level rise [JConway]
  • The Sand Dune complex at Newborough and Aberffraw – allegedly created by a series of bad storms in the 13th century are currently being eroded – a combination of rising sea level and greater storminess could wreak havoc with this Special Area of Conservation. Even if it doesn’t suffer physical damage, rising sea levels will bring rising water tables which together with salt water incursion will change the habitat and plant community beyond recognition.
Dune slacks and eroding dune, Aberffraw
Dune slacks and eroding dune, Aberffraw [J Conway]

The ambition to cut greenhouse gas emissions to net zero will fail without “nature based solutions” such as restoring peat bogs species rich grasslands such as hay meadows and planting new hedges and woodland.

Fortunately the Isle of Anglesey County Council have approved a new biodiversity plan to counter climate change. Let’s hope they keep to it and it is sufficient.

The National trust look after many areas of coastline, wild landscapes as well as fancy houses. Watch their video on climate change

Farmers could play a major role in reversing climate change caused by agriculture. Our food supplies are just another part of the natural food web – one that we manipulate – more on the next page humans.

Landscape

Our landscape is composed of geological features and ecosystems. the Geological Society have an excellent section on geology and climate change including a report on Climate change: evidence from the geological record So how will our landscape change? Apart from the ecosystem and biodiversity effects mentioned above and the agricultural changes, we may see increased erosion, flooding, landslips, subsidence and weathering of our soils and rocks.

Sea level and coastal areas

Coastal areas are affected dramatically by sea level changes – but so to are river valleys. Video on how to adapt to sea level rise.

The Geomon UNESCO Global Geopark will be particularly affected by sea level rise and increase wave action ; most of the best geosites are around the coastline – these could be drowned, subjected to damage by erosion or totally removed. Access to them could also be impacted.

Anglesey has a mix of coastal features and habitats – sandy beaches, sand dunes, rocky shore, hard rock cliffs, soft sediment cliffs, salt marshes, mudflats, storm beaches, raised beaches, caves, arches ……

  • The Sand Dune complex at Newborough and Aberffraw – allegedly created by a series of bad storms in the 13th century are currently being eroded – a combination of rising sea level and greater storminess could wreak havoc with this Special Area of Conservation. Even if it doesn’t suffer physical damage, rising sea levels will bring rising water tables which together with salt water incursion will change the habitat and plant community beyond recognition.
the sand dunes at Newborough are eroding fast [JConway]
  • Raised Beaches are a special land form created since the end of the Ice Age by the land rising isostatically [meaning the land was depressed by the weight of ice and since the ice has melted away, the land is rising back to its original level. Beaches created by the sea get lifted above sea level and colonised by plants, or even buried beneath wind blown sand. Climate change bringing rising sea levels will reverse this process and the former raised beaches will either become active beaches again or even be eroded away.
Some beaches are rising out of the sea and being colonised by vegetation [JConway]
  • Soft sediment cliffs and coastlines : much of Anglesey’s coastline is threatened with severe erosion due to rising sea level bring it within the range of wave action, and increasing storminess making that wave action more severe. The soft sediment coastline runs from the Menai Strait round Newborough, passed Malltraeth, Aberffraw and Rhosneigr up to Cwymyran with just a few rocky headlands separating a coastline backed by extensive sand dunes, sand flats and in places glacial till. On the east coast, Dulas [a huge sandy estuary just covered at high tide], Lligwy [backed by glacial till], Red Wharf Bay [from Benllech round to Llanddona, a big sandy beach area backed by glacial sediments] and on the Menai Strait from Penmon to Beaumaris, low cliffs of glacial till, moraine and other outwash sediments. fresh cliff falls in the glacial sediments are wonderful aid to studying the detail of deposition and source of erractics but do mean that the coastline can retreat very fast. Installing hard coastal protection from large boulders to concrete sea walls can slow down or possibly stop the erosion but present a conflict by “burying” the natural features, some of which, as at Lleiniog, are of great geological interest and international significance – as well as being strongly opposed by local people when the defences damage their local heritage. Recent events at Nefyn illustrate the threat to soft sediment coastlines
The coastline at Lleiniog in a variety of glacial and fluvioglacial sediments is eroding fast
The coastline at Lleiniog in a variety of glacial and fluvioglacial sediments is eroding fast [JConway]
  • Hard rock cliffs : although seemingly eternal, hard rock cliffs and headlands are slowly being eroded, often mainly by catastrophic failure in major storms. Many of Anglesey’s rocky coasts are ancient Cambrian or Precambrian schists which are riven by numerous faults and thrusts and other planes of weakness – and are not that hard a rock anyway. Pounding waves can dislodge large blocks or boulders, as well as undermining the cliff by carving out caves, blowholes, arches and leaving stacks looking perilously unstable!
 rock fall during winter 2020/21
rock fall during winter 2020/21 [J Conway]

Back to Top

Translate »