Trout anglers are being requested to keep a record of their catches to give up to date information on stocks in the north-east of England.
The Environment Agency hopes anglers will send details of size and species, and the location of the catch.
This will give a picture of the size and diversity of fish populations, and the extent of fishing in the area.
Survey methods used in the past, such as electric fishing and netting, have provided only limited information.
Fisheries officer Michael Donkin said: "It is hoped that by using angler catch data more information about stocks of trout in the area will be gathered, helping us to understand more about the distribution and health of the stocks."
Logbooks are available from the agency's fisheries office in Newcastle.