Shaun Layton, of Low Hill Crescent, will pay fines and costs totalling £611.47 after the case was proved in his absence by magistrates in Northampton on Tuesday.
Layton, 32, was charged with fishing without a licence after he was seen fishing at Baden Hall Fishery, Eccleshall, on September 30 last year by an Environment Agency enforcement officer.
A spokesperson from the agency said: “An annual fishing licence costs just £30, yet a small number of anglers continue to flout the law and risk prosecution for fishing without a licence and breaching bylaws in place to protect fish stocks.
“It’s important anglers have a licence before fishing; the money from licences is invested into England’s fisheries and rivers; improving the sport of angling.
“Anglers should also ensure that they are familiar with our bylaws, which are available on the Environment Agency web pages.”