Information on Freshwater Fishery Resources at the Freshwater Fisheries Laboratory, Pitlochry.
Remit of the Freshwater Fisheries Laboratory (FFL)
The remit of the Freshwater Fisheries Laboratory is to assess the current status of the Scottish fisheries for migratory and freshwater fishes and the populations on which they depend, and to record and quantify any significant modifications to their environment, especially those caused by nationally significant inputs of pollutants or changes in land use. To fulfil these objectives the Laboratory undertakes a programme of research which is sufficiently broadly-based to record change and also to investigate the main mechanisms which underlie it.
Species Base
The interests of the FFL extend to all of the exploitable or potentially-exploitable fishery resources in Scottish fresh waters and the fish and invertebrate populations whose habitats they share. The following provides an overview of the range of fish species about which FFL has information.
Atlantic salmon
Extensive data are held on catches and juvenile distribution and abundance. Intensive study of monitored sites provides life table and stock and recruitment information for successive cohorts. There are supporting experimental programmes on the ecology and genetics of the Scottish salmon resource.
Trout
The FFL holds extensive distributional and sampling data for the main types of Salmo trutta. These data are currently supported by specific investigations, especially of sea and 'ferox' populations, and by genetic expertise.
Arctic charr
Arctic charr have been studied especially in Loch Rannoch where 3morphs co-exist. Arctic charr is the principal fish prey of 'ferox' trout.
Brook charr
The brook charr is a North American riverine charr with a number of long-established Scottish populations. FFL studies have shown that brook charr thrive only in the absence of Salmo trutta which readily out-competes it.
Grayling
Grayling support an important recreational fishery which is monitored informally by the FFL. On present evidence, the Scottish populations are well able to sustain current levels of exploitation.
Rainbow trout
FFL have examined the growth and survival of rainbow trout in different Scottish freshwater systems with particular reference to the overlap in feeding ecology with Salmo trutta. There is little evidence that rainbow trout are successful in establishing self-sustaining populations in Scotland.
Sparling or smelt
This close relative of the salmonids has supported small scale, spawning season fisheries on the Rivers Cree and Tay. The FFL maintains a watching brief on the Tay fishery and it appears to be operated on a sustainable basis. However, the Cree fishery has not operated for the past 4 years due to concerns about the population status of sparling in the river. There is therefore limited development potential.
Eel
FFL and HIDB investigations have shown that members of many Scottish eel populations are very slow-growing. FFL maintains a watching brief on the eel fishery. It is also collaborating with a student project on eels on the Clyde.
Pike
Pike have been studied by FFL scientists primarily in their role as salmonid predators. Past work has studied the home ranges of pike in shallow lochs. Current interest is in quantifying the role of pike as juvenile salmon predators on the River Conon.
Cyprinid fishes
There is increasing interest in fishing for cyprinid fishes in Scotland, especially carp, tench, rudd and roach. The FFL has direct experience of studying cyprinid fishes under Scottish conditions and maintains a watching brief on their spread.
Perch
A synopsis of perch biology has been prepared for EIFAC by FFL.
Shad (Allis and Twaite)
The two species of shad occur as anadromous migrants in a number of South West and East coast Scottish rivers. Whilst sexually mature and spent fish have been caught, there is no conclusive evidence of self-sustaining populations in the rivers where they occur.
Lampreys (Sea, River and Brook)
Detailed data have been collected by the FFL in support of SNH. Widespread distributional data have been collected during routine electro-fishing surveys. Lampreys appear from FFL surveys to be doing well in Scotland.
Other fish species
All fish species caught during routine FFL electro-fishing surveys are recorded. The FFL recently supported a detailed investigation into the age structure of a stone loach population on Tayside.
Pearl mussels
The FFL has supplied information on the occurrence of pearl mussels to fellow investigators on request. This species receives special protection because of past over-exploitation. A further indirect challenge in NW Scotland is the shortage of anadromous trout to spread pearl mussel glochidia (the distributive phase which attaches itself to fish gills).