Junior rod licences are required for children aged 12 to 16 and cost £5.
A new £1m contract given to the Angling Trust by the Environment Agency will hope to arrest the decline by bringing more people into the sport.
Sarah Chare, head of fisheries at the EA, said: “We are working hard with the Angling Trust to encourage more young people to give fishing a go.
“Increasing participation amongst existing and new anglers is an important element of our new contract with them.”
Angling Trust chief exec, Mark Lloyd added: “The Angling Trust is determined to reverse the decline in junior participation. Over the next year we will be expanding our existing programme, funded by the EA rod licence, to promote angling to people of all ages through our Family Fishing initiative, in partnership with Get Hooked on Fishing, and some exciting new projects.