Sea Fishing in the UK started to seriously deteriorate in 1973 when our waters were given up to Europe and the voracious foreign trawlers.
Today commercial fishermen net to within 50 yards of the beach, they trawl to within 200 yards and are relentless - their livelihoods depend on them catching fish to put food on the table, pay the mortgage etc. but the impact on recreational fishing is massive.
The point about the War years above is correct, if we could stop commercial trawling for 5 years and then re-introduce it in a more managed way with no discard madness etc we would see change but it will never happen.
As far as stopping recreational anglers fishing by having a 'closed season' I doubt if every fish caught in a day by every single angler in the Country whether fishing from shore, pier, private or charter boat would equal a single haul by one of the larger trawlers.
Just a thought.
Tim R