SoNaRR 2025 Biodiversity assessment

A Welsh biodiversity assessment is necessary to ensure that the strategies, programmes and policies in Wales are fit for purpose, are implemented, and are able to achieve the results expected of them.

The biodiversity assessment draws upon evidence from across SoNaRR2025, as well as other published material and global analyses, to outline the state of biodiversity relevant to Wales. It is supported by case studies illustrating the plight of some of Wales' key species and habitats. These aim to inform action to improve the state of biodiversity.

Summary

It is a critical time for conservation efforts in Wales. One million of Earth’s estimated 8 million species of animals and plants are threatened with extinction and 75% of the Earth’s land surface has been significantly altered by human actions. In response to the unprecedented decline in global biodiversity, the Kunming-Montreal Global Biodiversity Framework was established with the ambitious goal of halting and reversing biodiversity loss by 2030. This framework aims to prevent further extinction crises, ecosystem collapse, and the degradation of ecosystem services.

The State of Nature Report 2023 highlights that Wales is one of the most nature depleted countries in the world. Evidence from the last 50 years shows that on land and in freshwater significant and ongoing changes in the way we use and manage our land combined with the effects of climate change, are having the biggest impacts on our wildlife. In Wales all ecosystems are to some extent impacted by human activity or land use, with 90% farmed.

Whilst there is evidence of recovery for some species, for example certain bat species and bittern Botaurus stellaris, urgent action is required, and transformative changes are essential in how society interacts with nature to achieve the Global Biodiversity Framework 2050 nature-positive goal that nature will thrive.

This biodiversity assessment makes use of the best available evidence building on the State of Nature Report, in addition to drawing on a range of recent reports on the current state of biodiversity in Wales, and the on-going conservation responses working towards a nature positive future. It highlights that while some action is being taken and can contribute to halting the decline in biodiversity, such as reintroducing species and protecting vulnerable populations, there remains a need for significantly more comprehensive and coordinated efforts. It also highlights that failure to take action and the alternative to halting biodiversity decline, could result in the loss of ecosystem services that are essential for human wellbeing.

Follow the link to the full Biodiversity assessment in our State of Natural Resources Report 2025.

Key evidence sources

• SoNaRR2020 Biodiversity Assessment
• State of Nature Report
• First Habitats Regulations 9A Report for Wales 2025 [in prep]
• Terrestrial and Freshwater Species in Peril in Wales
• Nature Positive 2030
• Sites of Special Scientific Interests: a Review of the Current Series in Wales
• ERAMMP Report-105: Wales National Trends and Glastir Evaluation
• UK Biodiversity Indicator: Protected Areas
• Birds of Conservation Concern in Wales
• Biodiversity Deep Dive Recommendations
• Welsh Government: A 30by30 framework for Wales
  
  

Case Studies

Atlantic Salmon Salmo salar

Region: North East

Atlantic Salmon populations in Wales have declined at unprecedented rates over the past decade. The recent IUCN Red List assessment of extinction risk for fish in Great Britain and in Wales has categorised Atlantic salmon as endangered. For some years, salmon numbers in particular have experienced a pronounced decline across their southern Atlantic range. On all Welsh rivers, this means that, on many rivers, the numbers of fish returning to spawn are now below safe levels.

The River Dee is one of 6 Special Areas of Conservation designated for Atlantic Salmon in Wales, it is also probably the most regulated river in Western Europe. The LIFE Dee River project is a £6.8m initiative, which aims to transform the River Dee and its catchment by restoring the ecological function of the river and its riparian habitat. Running from 2019 to 2026, this project will bring many benefits to the environment, most notably by improving the quality and accessibility of habitat on which salmon and other fish populations depend.

Natural Resources Wales / LIFE Dee River

Whiteworm lichen Thamnolia vermicularis

Region: North West

The whiteworm lichen Thamnolia vermicularis is a widespread species in the far north of Eurasia and North America, also growing on exposed mountain ridges further south in Europe. People tend to think that species found in remote areas are safe from harm, but Climate Change and air pollution are affecting species across the whole of Wales.

NRW Evidence Report 670 highlights three potential causes of the extinction of whiteworm lichen in Wales: Climate Change, long-range air pollution by nitrogen compounds, and sheep grazing and dunging favouring grass growth. It seems likely that all three factors have combined to cause the closing in of open habitat on our mountain tops, leading to the loss of this lichen and also to declines in other specialist lichens, bryophytes and invertebrates.

The Species in Peril report (NRW Evidence Report 818) identifies 304 species that have been lost from Wales since systematic biological recording began in the 1800s, of which 114 were last seen in Wales in the 1950s or later.

Invertebrates of Welsh Exposed Riverine Sediments

Region: Mid Wales

Exposed Riverine Sediments (ERS) are very dynamic and mobile habitats, dependent upon constant erosion and deposition and, as such, are highly sensitive to changes in river flow patterns. ERS supports important invertebrate specialist faunas dominated by beetles and flies, with 250 species recorded in the UK, which are reliant upon dynamic and open conditions. Welsh rivers rank as some of the most important for ERS invertebrate assemblages in the UK, with eight having nationally important faunas – Mawddach, Monnow, Rheidol, Tywi, Upper Severn, Usk, Wye and Ystwyth.

Continuing threats to the remaining Welsh ERS resource include engineering to alleviate flooding and reduce river flow rates, removal of gravels to protect infrastructure such as bridges and roads and for hardstanding for livestock, the compaction and eutrophication of sediments by cattle, siltation, agricultural runoff and vegetational succession as sediments become less mobile.

A survey of Afon Tywi ERS invertebrate fauna from June to September 2023 was the first detailed assessment since 1998.

Barbastelle bat Barbastella barbastellus

Region: South West

The barbastelle is one of the UK’s rarest bat species, with an estimated population of 500 in Wales. Barbastelles are notoriously difficult to find and monitor due to a variety of reasons including their light and sound sensitivities, reclusive nature, tendency to roost in small colonies and switch roosts every two to three nights.

It is hoped that the methods developed in within the The Barbastelle Bat Project can be used in other areas of Wales where it is suspected that small populations exist, and to help build a better understanding of this rare species in Wales.

Shore Dock Rumex rupestris

Region: South Central

Shore Dock (Rumex rupestris) is one of Europe’s most threatened endemic vascular plants. The UK is the world stronghold for this globally threatened coastal plant, which has faced significant challenges in Wales due to habitat loss, erosion and more frequent extreme weather events, driven by climate change.

In 2022 NRW commissioned a feasibility study into Shore Dock reintroduction, with the hope to restore it to the Dunraven Bay SAC and Southerndown Coast SSSI. Following the study a collaborative project led by NRW was granted funding by Welsh Government’s Nature Networks fund.

The goal for the success of this restoration project is for few populations with several plants reaching maturity, flowering, fruiting and setting seed, this would prevent the need for future interventions at these sites. Early surveys have indicated 73% of the plug plants were successfully located. However, there were no signs of germination in the sown seeds, monitoring will resume in spring 2025.

Eurasian Curlew Numenius Arquata

Region: South East

The Eurasian Curlew (“Curlew”) is a migratory species in need of urgent conservation action both in the UK and Wales. The Curlew is predicted to be on the brink of extinction as a viable breeding species in Wales by 2033.

Curlew require a large and coherent network of heath and grassland landscapes that are actively managed to influence breeding success, such management will also provide habitats to benefit other biodiversity priorities and underpin ecosystem resilience. The Wales Action Plan for the Recovery of Curlew Recovery Plan | Curlew Wales was published by Gylfinir Cymru in 2021 identifies the outcomes required to achieve a sustainable recovery in the long-term, especially those interventions relating to land-use management. The development and delivery of the Sustainable Farming Scheme to provide long term, landscape scale management along with continued partnership working is vital if the iconic call of breeding Curlew is still to be heard across our farmed landscapes in years to come.

Saltmarsh – Annex I feature of Severn Estuary SAC

Region: South Central

Saltmarsh habitats form an important part of the health and stability of coastal ecosystems and their conservation is vital for protecting the diverse range of species that depend on them.

This project will help restore the important saltmarsh habitat of the Severn Estuary, supporting local wildlife and helping to trap carbon. This nature based solution could also help to enhance the existing flood defences and reduce future flood risk by reducing pressure from erosion.

The project was funded through the Welsh Government funded Nature Networks programme (2022-2025) which aims to increase environmental resilience and biodiversity.