The threats of U-boats is likely to have made fishing at sea dangerous. On the other hand shortages of food may have increased the need for fish more urgent. Since Britain imported food, the risks of fishing at sea might have been less than the risks of bringing food from other countries to Britain by sea. What happened to Britain’s fishing during World War Two?
From “report of the study group on the history of fish and fisheries” (2011)
“…the two World Wars (1914–1918 and 1939–1945) brought the North Sea fishery to a near-standstill with great effects on the fishing sectors in Great Britain. Especially for the English trawling industry the impacts of the wars were severe as fishers and the largest and most modern fishing vessels were requisitioned for naval service, leaving England only a fraction of its former trawling fleet. Many fishers and fishing vessels were lost in the act of wars.”
I don’t know the answer, but it seems to me that a small, wooden fishing boat wouldn’t be worth a torpedo and also wouldn’t be worth to a U-Boat skipper giving away his position even if he were to engage with deck guns. But the serious , commercial fishers, would be larger , metal hulled trawlers and those might be another story.
There were a couple of ways of losing fishing trawlers. One way was requisitioning them as anti-submarine and minesweeping vessels. Especially early in the war, the Brits were so short of anti-submarine (and rescue, in the channel, for instance) that they ‘stole’ over 800 for the “Royal Naval Patrol Service” by the end of the war. Also early in the war (until about 1941) submarines weren’t so afraid of aircraft – they would use deck guns. But the most deadly form of anti-submarine was naval mines.
The Germans strategy until aircraft began to patrol most of the North Atlantic was to starve Britain into submission. Neutralizing the fishing fleet was part of the targeting.
Hope this helps!
It is because the German government tried to starve Britain, that keeping the fishing going might have been an aim of the British government. Fishing at sea in time of war was risky, but so was transporting food from far away countries by ship.