Freshwater
Lakes, reservoirs and ponds, rivers and streams, canals
The State of Nature in Freshwater in Neath Port Talbot
Freshwater ecosystems are well represented in NPT and many of the specific habitats in this category support a large diversity of plants and animals. This includes important aquatic and marshland communities which contribute to the overall connectivity of marsh, fen and swamp in the county. Many are in good or reasonable condition but there are local concerns with mine water pollution, eutrophication and the occurrence of invasive non-native species. While river water quality has undoubtedly improved in recent decades, and this has benefitted populations of salmonid fish and their predators (e.g. Otter), more improvements in water quality are required.
The resilience of and state of nature in freshwater ecosystems in NPT has been assessed as fair.
OVERVIEW
Freshwater ecosystems provide habitats for a fifth of NPT’s priority species, many of which are associated specifically with this habitat. Specific habitats in this category include rivers and tributaries, canals, lakes, reservoirs, reens and dykes, and numerous ponds and pools scattered throughout the county. Key priority species include Otter, Water Vole, Great Crested Grebe, Dipper, Spotted Flycatcher, Grass Snake, Great Crested Newt, Atlantic Salmon, Brown and Sea Trout, Fen Raft Spider, Flowering Rush, Quillwort, Water Lobelia, Floating Bur-reed and Whorled Water-millfoil.
Among the larger freshwater water bodies in NPT, Llyn Fach is unique in being the only significant oligotrophic tarn in Glamorgan. The occurrence here of an aquatic community that includes Water Lobelia, Quillwort and Floating Bur-reed gives the site a very distinctive montane feel. In addition, the recent discovery of a population of Water vole, hitherto believed to be extinct in the county, has confirmed the importance of this site for the county’s biodiversity. Other large lakes and reservoirs in NPT include Eglwys Nunydd Reservoir, which is an important site for wintering wildfowl and a breeding habitat for Great Crested Grebe.
The Neath, Swansea and Tennant Canals support diverse aquatic and emergent vegetation and provide crucial connectivity between a number of fen, swamp and marsh habitats in the county (e.g. Crymlyn Bog, Pant y Sais Fen). Notable plants include Flowering Rush, Greater Spearwort, Marsh Cinquefoil and Mare’s-tail which are otherwise scarce in NPT. All the common damselflies and dragonflies are found here as well as other more notable species such as the Variable Damselfly and Beautiful Demoiselle. The occurrence of Fen Raft Spider at its only site in Wales on the Tennant Canal is particularly significant. The reens on Margam Moors contain a number of scarce aquatic plants such as Arrow-head and Frogbit.
The River Afan and River Neath, and their tributaries, are notable for their fish populations particularly salmonids such as Atlantic Salmon, Brown Trout and Sea Trout but also for populations of European Bullhead and European Eel. Common Sandpiper, Dipper and Spotted Flycatcher are among a number of characteristic bird species associated with these rivers and Otter have made a welcome comeback in recent decades. Meadow Saxifrage, a plant which has undergone a significant decrease in Wales is still frequent along the banks of the River Neath between Aberdulais and Glynneath.
The waterbody status of the main watercourses in NPT have been recorded as Good/Excellent by the Water Framework Directive. However, there are still a number of local issues that are of concern on its rivers and canals, e.g. invasive non-native species, mine water pollution, sewerage discharge and other eutrophication problems.
Actions for the recovery of
Freshwater habitats in NPT
Responsibility for these actions lie with all of us and as such, we have not sought to assign actions to particular organisations or groups. Instead, it is our hope that this document will provide the guidance and inspiration for anybody, or any group or organisation, to undertake the actions that are within their capability to deliver. The Secretariat of NPT LNP (NPT Council) are providing a facilitation role to support, collate and monitor work towards these actions. If you would like to discuss your potential involvement in delivery of these actions, please get in touch with biodiversity@npt.gov.uk.
OTTER
Increases in the national Otter population in recent decades are viewed by most people as a welcome indicator of the renewed natural health and vigour of our riparian habitats. The widespread occurrence of Otter spraint on riverside rocks and other stone structures reveal the widespread occurrence of Otter on NPT's rivers and canals. Nevertheless, there is some evidence that numbers have decreased in recent years and there are indications of occasional persecution.
SALMON
All the major river systems in NPT have Salmon in them. It is becoming more obvious that Salmon are in crisis throughout the UK as well as Wales with suggested figures of a decline of 70% in 25 years (Atlantic Salmon Trust). Read more in the case study below. The video above shows a salmon migrating through the Green Park Weir fish pass in 2015.
DIPPER
Dippers occur on fast-flowing, unpolluted streams and are seen regularly on most river catchments in the county all year round. In 2019 there were a minimum of 12 confirmed breeding locations in NPT. Current studies of this amber-listed species include a ringing program being conducted on the River Afan and its tributaries, aimed at increasing our knowledge of local breeding success and survival rates over time.
Freshwater Projects in NPT
CASE STUDY
THE ATLANTIC SALMON IN NPT
The Atlantic Salmon is an anadromous fish with a lifespan up to 13 years. It is becoming more obvious that Salmon are in crisis throughout the UK as well as Wales with suggested figures of a decline of 70% in 25 years (Atlantic Salmon Trust).
The River Afan and River Neath within NPT are not considered principle Salmon rivers and as such there is less data available to confirm a decline. However the data that is available from anglers and Natural Resources Wales suggests that the local figures support the crisis theory. The first recorded rod-caught Salmon for more than a hundred years on the River Afan was in 1988. There has been modest increases since then with last season’s figures (2021) of 19 Salmon. All were returned unharmed. The water quality in the river is in no doubt improved and better now than it has been for decades and therefore should encourage these fish to spawn if they make it back from their feeding grounds and migration. Although it would appear that the River Afan is holding its own as a small river, with so few fish returning it is difficult to be optimistic.
The River Neath Salmon figures over the last 11 years show a significant decrease where in 2011 recorded 77 Salmon caught decreasing to 16 in 2020.
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Survival of smolts and post-smolts seems to be the issue for all our rivers in South Wales. Rate of survival to returning adults have dropped from 15% in the 80’s to just 3% in more recent times. There is no doubt that the demise of the Salmon is down to a number of factors, from pressure in the marine environment to their breeding efficiency in fresh water. Losses can be quite high ‘in-river’ due to the combination of man-made barriers and predation by birds/ Otters. For this reason future focus is more and more about downstream migration of smolts and their progress over the numerous weirs. For the present, attempts to reduce the decline in population, by various legislation and water catchment initiatives is in place but the fact is that these magnificent creatures are in real danger of becoming just another statistic.
