According to this website:
He discovered that tinned asparagus was included as part of the emergency ration kit given to American pilots in the Pacific Ocean region, who were working for the US spy organization called the Office of Strategic Services.
The idea of the pilots eating asparagus was a clever one because those who were shot down, or stranded on remote islands had a very valuable way of feeding themselves. Asparagus contains mercaptans which are powerful chemical attractants, and when the vegetable is eaten, these chemicals pass into the urine. The pilots were told to urinate into the water, so that the chemicals would spread through the water and attract fish to the area, making them much easier to catch. This was of course, a valuable food source and the smell of asparagus is present in the urine after just fifteen minutes in many people, or thirty minutes at most.
Was it included in the emergency ration kit and does asparagus attract fish?