Cod stocks in the North Sea, the Atlantic Ocean west of Scotland and the Irish Sea have been in serious decline for decades and are now at their lowest ever recorded level.
North Sea haddock are also under threat, with scientists predicting a rapid decline in their numbers over the next two years.
Cod live mainly in the northern and central areas of the North Sea.
Spawning takes place between January and April and occurs in most offshore areas.
Haddock spawning grounds are concentrated in the northern North Sea and off the west coast of Scotland.
The spawning season for haddock takes place from March to May.