Mawddach Hatchery update 2009

May 11, 2010

This article covers the period from Autumn 2008 to the summer of 2009, and will report on the last twelve months work and developments at the Environment Agency’s (EA) Mawddach Hatchery at Dolgellau.

The last twelve months seem to have been busier than ever, with the dedicated hatchery staff producing excellent numbers of wild salmon and sea trout. Inline with the EA policy all of the fish produced at the unit are restocked back to the rivers where the parent broodstock originate. Details of all the broodstock collected, ova laid down and fish stocked out are shown below.

Other developments carried out in the last year include up-grading of the Fresh water pearl mussel rearing facilities and installation of new variable speed drive water pumps, and control systems.

The Mawddach Hatchery, which is owned and managed by the Environment Agency Wales, continues to produce high quality fish, and would like to acknowledge the support given by the following organisations;

The Mawddach Trust.
Dolgellau Angling Association.
Prince Albert Angling Society.
The Conwy Valley Fisheries Association
Environment Agency Thames region.
Kielder Salmon Hatchery (EA).

Fish stocked out 2008-2009.

The total number of fish stocked out from the hatchery during the period covered by this report was 124,280. This includes all age groups i.e. fed fry, 0+Parr and S1 Smolts. All the details are listed in appendix 1.

Broodstock collection and ova laid down Autumn 2008

Collection of broodstock in Autumn 2008 went very well with all targets, for numbers of ova for each rearing scheme, being achieved.  The total number of ova laid down was 166,820.    Details of these numbers are shown in appendix 2.

The Freshwater Pearl Mussel rearing project.

Whilst the hatchery staff have continued with their day to day work of rearing fish for all the restocking programmes, they have also been involved in the construction of a new purpose built freshwater pearl mussel hatchery and rearing unit. This work has been funded by the Environment Agency’s (EA) biodiversity team, who are working closely with the hatchery staff on the project.

Construction of the new FWPM rearing facility was competed in June       ( see photos), and the adult and juvenile mussels were moved into the new setup in July.

Investment in new water pumps and generator housing.

During the year the Hatchery replaced its old submersible water pumps with new variable speed drive units (VSD). A new pump house has also been built to house these new VSD pumps and their associated controls.
The purpose of installing the VSD pumps was to have control over the amount of water supplying the hatchery. The old pumps could only run at one speed, and at times when less fish were on site, and therefore less water was required the hatchery would be consuming far more energy to run the pumps than was actually needed. With the new VSD pumps the amount of water entering the hatchery can now be reduced or increased, depending on the time of year and the number of fish on site. Since their installation there has been a net decrease in the Energy consumption at the hatchery of nearly 40%.