Good old days when bluefin tuna abundantly captured by beach seine net

I have seen a picture depicting giant bluefin tuna caught by beach seine net flooded all over the beach. The picture was drawn in the medieval period in Cadiz, a famous historic town located close to the Strait of Gibraltar. Almost identical pictures can be seen in Japan. The pictures were actual photographs taken before the World War II in the beach of Sanin region in the western part of Japan facing Sea of Japan. In addition, I have heard of anecdotal story that southern bluefin tuna once captured by beach seine net.  There could be two kinds of interpretation about this picture, one is that there used to be a plenty of bluefin but now this kind of fishing is impossible due to depleted stock level, the other is that this kind of fishing became impossible due to avoidance of bluefin coming to close to the beach because of hazardous noise, lights, degradation of general beach condition created by human being. I tend to agree the second interpretation because it is a well known fact that bluefin repeats a big fluctuation of stock size caused by natural environmental changes. Beach set net targeting bluefin tuna may return someday.