Two fish for Nathan Jubb at Upper Bigswier Cockpit run 15 and 8lbs Ally's shrimp.
9lb coloured fish from Letton to Stuart Smith also on an Ally Shrimp.
A fish too from Spreadeagle, 8lbs to Ryland Thomas on fly.
Obviously been a movement of fish upstream or the residents have moved on a few beats as many are far from fresh.
Good to see the poor quality water from the Irfon is being diluted enough not to put some fish off.
Strangely another angler reports unusually peaty water from the Usk following the recent rise although he did take two fish from Dan-y-parc. Has anyone else noticed this unusually peaty water on the Usk. Irfon is still very dark - at least in the downstream sections?
An interesting read below regarding the possible poor results so far from liming on the Wye catchment taken from here; http://orca.cf.ac.uk/56101/1/U584856.pdf
Whilst larger main river sites may be expected to recover further than tributaries, through accumulation of drainage from limed tributaries upstream and from inputs from naturally well-buffered sources, it is clear that in the upper Wye, substantial inputs from untreated acid streams persist, and appear to override any positive effects of treatment that may have occurred at the main river.
Although the benefits of transplantation and in-situ bioassays survival studies have been used to elucidate links between acid toxicity and aquatic biota (Simonin et al., 1993; Claveri et al., 1995; Masters, 2002; Lepori et al., 2003; Hirst et al., 2004; Kowalik, 2005), the potential influence of experimental artefacts in such studies have also been recognised (Ormerod and Jenkins, 1994). Avoidance behaviour (predators, competition) and recolonisation behaviour is not possible for study organisms confined during experiments and the test population will only represent part of the real population. Moreover, animals suffering sub-lethal effects or animals which are partially affected and then recover, can give misleading results. However, in this study, mortality in circumneutral reference streams remained low, indicating that any detrimental effects of confinement within the enclosures were minimal. The results of in situ bioassay studies such as this are not always easily translated to conclusions 189 M ayfly survival in lim ed stream s about the natural population or community as whole.
This difficulty in extrapolating results necessitates an integrated approach to impact assessment, such as combining toxicity tests with chemical and biological monitoring surveys. Such an approach over larger-time-scales and with respect to an array of sensitive species, whose varying tolerances may elucidate some of the mechanisms behind biological recovery from acidification, will be required for accurate assessment of the on-going liming programme in the Wye, and the ecological consequences for the catchment. Further, whilst Fjellheim and Raddum (1992) recorded B. rhodani in limed streams in Norway, the species only appeared two years after treatment, demonstrating that as an on-going experiment,
the Wye liming project is not yet complete and the first two years of data should thus be used in preliminary evaluation. From a management perspective, it appears that liming has not yet achieved the stable chemical milieu suitable for biological recovery with conditions currently unsuitable for the survival of acid-sensitive macroinvertebrates. More extensive treatment targeted to address periods of high discharge will increase the potential for chemical and biological restoration to be achieved. 6.6 Acknowledgements BRL was funded by The Wye and Usk Foundation. Water
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