Several species of fish can be found in the river including Pike, Dace, Chub, Gudgeon, Perch and Roach. In recent years a good number of Barbel were introduced by York and District Amalgamation of Anglers and these have been packing on weight in the rich environment, waiting to surprise the unsuspecting angler.
The variety of fish present varies in different stretches of the Foss. Chub of around 1.5kg are caught in the odd spot where it is four feet deep. Roach up to 600g are present as well as plenty of smaller ones, and the odd perch reaches a kilo or so too. Occasionally a hooked fish is grabbed by a pike which can be 3kg or more!
Bigger fish tend to be found in the Strensall and Haxby areas, whilst more small fish are seen downstream. In New Earswick’s faster water, as well as elsewhere, both Dace and Gudgeon are to be found. In the city, Bream will turn up, as well as the odd Tench or Bleak.
Below Strensall the river is mostly slow moving and fairly uniform in character. Any ‘features’ such as marginal vegetation, overhanging trees, and structures such as drainage outlets tend to attract fish. Bream, Carp and Tench tend to favour the slower, deeper water and seem to be caught mostly in the lower reaches. For a small river, fish seem to reach a good size, which suggests good invertebrate life. You could almost certainly add eels to the above list but they’ve not been reported to date.
The Foss is not classified as a trout river but natural Brown Trout have been landed in faster waters, mostly above Strensall or associated with weirs as well as some ‘escapee’ Rainbow Trout of around 0.5kg.
A pollution incident a few years ago wiped out nearly everything in the river, but it was surprising how quickly the river recovered during the following six months; after a year it was pretty much back to normal! Happily many fish are big travellers and the Foss showed a remarkable ability to restore itself.