The catching or freshwater fish for food is not allowed in any fishing club I have ever been a member of, and it has been like that all my life.
We no longer have close season on still waters, and remember still waters are stocked at great expense to provide sport for the members, not for you to eat.
If you want to eat freshwater fish buy and stock your own personal fishery
Here, many angling clubs have a rule that allows people to take 2 fish home a day, other places they say, “take only what you can eat”.
Pike has to be larger than 60 centimeters before anyone is allowed to kill them and most people will release pike longer than 80 centimeters.
I have caught more than 30 pikes this year but only one below 80 centimeters, and several more then 1 meter, so it can be discussed if we should increase max. length to 90 centimeters.
We can take fish home to eat and still have plenty of fish in our fresh waters. However, any kind of pollution is delt with quickly and companies or privates who release pollution will be hardly punished. I will estimate that 90% of our rivers have drinking water quality. Lakes are mostly clean but it is not recommended to drink the water.
Denmark have around 1,3-1,4 persons pr. Hektar. UK has around 2,5-2,7 persons pr. Hektar, so your county is much heavily populated than ours, so you will have it much more challenging to keep nature clean.
Coarse angling is not particular popular here, certainly not at the degree it is in UK. For this reason many good places for coarse angling have no rules regulating the angling for anything other than pike and Zander. For the same reason many places whit few predator fish but large amount of coarse fish are completely free to be fished. One of my local lakes, Skanderborg Lake, where there have been a few Worls championships in coarse angling, only have rules for angling predatory fish. Only regulations on Coarse angling is that max. amount of feed is 2 kg pr day, pr angler, to keep pollution down.
My family loves fish, and we eat both freshwater and sea fish, but only fish we catch ourselves.
About crayfish, our native European crayfish are getting seldom, as the American Signal crayfish push them out. Last year I took the children to one overnight stay at the river, where we fished for crayfish using 6 crayfish pieces, result 23 kg Signal Crayfish.