Llynyfan (cont)

APPENDIX No. 1. RESTOCKING RECORD AND REQUIREMENTS

A1.1. Advances in the research of fish genetics have led to a strict policy which demands that salmon and seatrout cannot be mixed with those from other rivers - they must be river-specific. (Wilkins, Ryman 1980). So must brown trout (Winstone et al 1993).

A1.2. Stocking Requirements in West Wales

A1.2.1. Salmon and Sea trout Mitigation

Under the Provisions of the Llyn Brianne Order, a sum of money was allocated for future compensation to the Towy Fishery, for the loss of salmon and seatrout breeding grounds.  Initially, a trapping and trucking scheme was set up. Following its failure, mitigation has been provided by the stocking of reared fish, previously at Dolbantau, more recently at Cynrig (WWA 1978, 1982). Fish are also reared to meet a similar mitigation for Llys-y-fran.

A1.2.2. Compensation for Fishkills

A1.2.2.1. Pollution

A limited count was made of some of the reported fishkills in West Wales. The data were extracted from WWA and NRA Committee Reports, and other papers. Those just for the Towy and Taf catchments, revealed a total of 114 fishkills between 1978 and 1993. Varying from 1 to 24 a year, with an average of 6 a year. A number of these were total 'stream wipe-outs'; thousands of fish killed in a single incident. Table A 1.2 lists some of the fishkills reported, 1981 - 1987 (Clarke et al 1987).

A1.2.2.2. Flood defence

Previously known as land drainage, these activities can cause fishkills. No counts have been made because the effects are well documented. Low juvenile densities in the lower Llandovery Bran were attributed to regular maintenance of a Capital Scheme (Clarke et al 1987). 2079 m of Nant Gwydderig's river bed were affected during the Abertreddfin A40 road widening scheme. NRA calculated actual salmonid losses of 645 fry and 520 parr, in addition to general derogation (Roblin pers comm 1991). Maintenance work on the Western Cleddau being another prime example.

A1.2.3. Enhancement

A1.2.3.1. A Report published by the Salmon Advisory Committee, called for hatchery rearing programmes specifically aimed at restoring diminished runs of Spring salmon (MAFF 1994). NRA's Draft Salmon Management Strategy Report made similar recommendations (Mills 1994).

A1.3. Actual Stocking in West Wales 1975 - 94.

A1.3.1. A record of stocking into local rivers, excluding brown trout, was compiled by NRA. The data revealed that originally, WWA, and subsequently DCWW/NRA, failed to meet the mitigation stocking obligations for both reservoirs. During 1990 - 93, the Towy was understocked by some 40%; the Cleddau by 60%. A total of some 47,000 smolts. There was no stocking at all in 1991. No Towy eggs were laid down in the winter of 1993/4 (NRA 1994).

A1.3.2. Salmon and Seatrout

Enhancement stocking has been very limited, and confined to other local rivers. The Scottish salmon stocked into the Teifi in 1984, were purchased by Llandysul AA - before genetic constraints were introduced.

A1.4. Additional 'Natural' Production - A Suggestion

Table A1.2. Reported fishkills in the Tywi catchment, including the Cothi and Gwili sub-catchments from 1981 - to date (=1986). From Clarke et al (1987).

Date
River Stretch affected 
From To (SN) (SN)
Cause

back     contents    next