Personally, I had the chance to do scientific fishing with the Maurice Lamontagne Institute.
I was fishing once a week, and I was allowed to catch 300 kilos of fish before bringing my catch back to the wharf, where someone would measure it and collect two of each size. Usually, we'd get four or five small mackerel that were 27 centimetres or smaller. I caught some very large ones that were 39 centimetres, not in large quantities, but there were some. With half of my staff, I could get my 300 kilos in 25 minutes, and I didn't have to go far.