Ecological Surveys of Welsh Lakes 2016

This project set out to collect, process and supply to NRW ecological and environmental data from a network of 14 lake sites across Wales, in support of NRW’s integrated monitoring programme for protected sites (SACs and SSSIs), the Water Framework Directive, Nitrates Directive, Biodiversity Action Plans and other legislative and policy drivers. In particular the surveys are aimed at informing management and restoration of protected sites and facilitating delivery of River Basin Management Plans. Using standard methods, lakes were surveyed to assess the species and abundance of aquatic plants growing within and directly around the lake and to measure water clarity, dissolved oxygen and temperature within the lakes. · The aquatic plant species are listed within the report and the complete survey results supplied to NRW as MS Excel spreadsheets. · Calculations are presented for the onward use of determining the ecological status of the lakes with respect to the Water Framework Directive (LEAFPACS). The results of the aquatic plant surveys are suitable for the purposes of assessing site condition for Habitats Directive standing water features and SSSI status. The lake metrics are applicable for the production of ecological quality ratios from which the lakes may be classified in accordance with the requirements of Water Framework Directive (2000/60/EC) Ecological Surveys of Welsh Lakes 2016 (NRW Evidence Report No. 204). Available from: https://www.researchgate.net/publication/318135626_Ecological_Surveys_of_Welsh_Lakes_2016_NRW_Evidence_Report_No_204 [accessed Sep 29, 2017]

A palaeolimnological investigation at Crazy Well Pool, Dartmoor

This report presents the results from a short sediment core taken at Crazy Well Pool, Dartmoor. In addition to physical sediment analysis (loss on ignition and dry weights), siliceous microfossils (diatoms) have been used in an attempt to reconstruct lake pH changes and other water quality parameters. The core has also been dated using a technique based on the concentration of spheroidal carbonaceous particles (SCPs). The core showed a reliable chronology spanning in excess of 150 years and the diatoms were well persevered. A total of 65 species of diatom were recorded. A notable switch from benthic taxa at the base of the core to more planktonic species towards the core top was observed. Diatom pH reconstructions inferred that the lake has become slightly less acid over a post-industrial timescale, which is contrary to many other studies of UK lakes on base-poor geology. These results suggest that changes in catchment management have resulted in pH increases in the lake, despite evidence of acid deposition at the site. Information on diatom habitat requirements also suggests that lake levels have been lower in the past

Floating water plantain Luronium natans (L) Raf.: Current distribution and status in Llyn Padarn and Llyn Cwellyn, Wales

Luronium natans is native to the UK and is protected by UK and European law under Annexes II and IV of the Habitats Directive, Appendix I of the Bern Convention, Schedule 4 of the Conservation (Natural Habitats, etc.) Regulations 1994, and Schedule 8 of the Wildlife and Countryside Act, 1981. It is also listed as UK priority BAP species and the current distribution is restricted to less than 100 hectads in the UK and it should therefore be classed as nationally scarce (Lockon 2014). The main stronghold for the species is in the oligotrophic lakes of central Wales and Cumbria, as well as some canals in Wales and Shropshire (Preston et al. 2002). Due to its deep-water habit, L. natans is easily overlooked and although this may have resulted in it being under-recorded in some locations, there is also evidence of it having been lost from some lowland sites in recent years (Preston & Croft 1997). In Llyn Padarn, Luronium natans was first recorded in 1848 (Kay et al. 1999), and more recently is known to have been relatively common with records from at least 4 distinct locations reported by Andy Jones in 1997 (CCW Species & Monitoring Report No. 98/02/11 - Luronium natans (floating water-plantain) at Llyn Padarn SSSI) ( Figure 1). Survey data since 1997 are less complete. The aquatic flora was surveyed using Common Standard Monitoring methodology (JNCC 2005) for WFD assessment (Goldsmith et al. 2005, 2010, 2013), but this method does not necessitate whole-site assessment and L. natans was only recorded in one survey section at the south east end of the lake (an extensive bed from 0.8 – 2.4 m water depth). The other survey sections did not coincide with earlier L. natans records and therefore the extent of the species within the lake since 1997 has not been verified

Inventory of ponds in the Norfolk Coast AONB - recommendations for pond survey and conservation

The banning of tributyltin (TBT) from boat antifouling paints in the late 1980s led to its replacement by alternative biocide additives (Voulvoulis et al., 2000; Marcheselli et al., 2010), including Cu (Dahl & Blanck, 1996) and Zn as active ingredients. It has been reported that Cu and Zn compounds associated with these biocides have caused substantial contamination of harbour and marina sediments (Eklund et al., 2010; Parks et al., 2010), with negative toxic consequences for aquatic organisms (Ytreberg et al., 2010). Indeed, it is evident that Cu and Zn compounds present in paint fragments are readily leached into the water column allowing entry into aquatic food webs (Jessop & Turner, 2011). Nevertheless, relatively little is known regarding antifoulant-derived metals contamination in freshwater lakes. The Norfolk and Suffolk Broads (Eastern England, UK) have been contaminated by antifoulant-derived heavy metals, particularly Cu and Zn which have increased since the banning of TBT (post-1987) in parts of the boated system (Boyle et al., in prep.). Further, recent studies suggest that current levels of sediment contamination by Cu may have negative ecological effects for aquatic ecosystems including inhibition of aquatic macrophyte germination and performance (Boyle et al., submitted; S. Lambert, unpublished data). In Hickling Broad (Thurne Broads system), post-TBT increases in Cu and Zn are also evident, with an interesting peak in Cu for the late 1990s in core HICK1 (Figure 1). This coincides with the large-scale loss of aquatic macrophytes (especially Characeae) from the lake in 1999 (Barker et al., 2008). HICK1 was collected in 2003. In the proposed study we sought to gain a fuller understanding of recent metal contamination in Hickling Broad up to the present day, whilst looking to verify and better contextualise the late 1990s Cu peak. Further, we aimed to determine whether the peak in Cu for Hickling Broad was also recorded at Horsey Mere which is used as a control site in this study i.e. is it just a Hickling phenomenon? Or is it a Thurne Broads system-wide effect

Modelling phosphorus fluxes in Loweswater

1. This is the final report to the Loweswater Care Project (in support of the Catchment Restoration Fund for England) ECRC-ENSIS Project 298, 'Loweswater 12-13'. The study was concerned with the spatial and temporal concentrations of sediment phosphorus (P) in the lake and the use of P measurements from the water column and inflow and outflow samples to derive a simple mass balance model for P in the lake. 2. A review of published and unpublished literature on Loweswater highlighted trends in water chemistry since the mid-eighteenth century. Land use and farming practises have changed over the past 200 years which have led to increased nutrient loading to the lake with significant increases occurring in the mid part of the last century. Agricultural intensification is likely to be a significant cause of the problem as well as inadequate septic tank management. Local management efforts, led by the Loweswater Care Project, has sought to reduce the primary sources of nutrients reaching the lake, but total phosphorus (TP) concentrations in the lake remain higher than desired. 3. Temperature and dissolved oxygen (DO) profiling confirmed that the site stratified in summer with major changes in DO occurring below a depth of 8 m. The deeper waters were almost entirely anoxic. During stratification the maximum TP value was recorded at the lake bottom. This is a clear indication that P is being released from the lake bed during summer stratification. 4. Analysis of the stream water from the Dub Beck inflow (data for 2013), shows that P influx remains high enough to explain the elevated lake water P concentrations, despite considerable efforts to reduce catchment P sources. 5. Analysis of the water column P profiles shows that P release from the sediment is only a minor contribution to the P load. While the sediment core data reveals a substantial pool of P in the sediment very little of this should be released each year to the water column. In 2013 it is estimated that more than 90% of the P came from the catchment and only ~10% from the sediment. 6. As with all modelling exercises there are uncertainties inherent in the approach. In this case the model output is based on a single year of input data for the inflow P flux calculations and it would be preferable to have a longer data series to inform the modelling. Inflow fluxes are highly dependent on flow conditions and here, in the absence of flow data from Dub Beck, we used data from a nearby stream. Further, the monthly sampling has resulted in most samples being taken in low flow conditions, thus missing potential storm flow conditions. Finally, stream input information is restricted to Dub Beck, and contributions from the other stream is unknown. 7. Nevertheless, the results from the modelling are clear and on that basis we conclude that the priority is for P loading to the lake to be reduced by better catchment management and that lake manipulation is not warranted. Integrated catchment management supported by modelling together with local stakeholder engagement should provide the most effective means of improving the condition of the lake