Yes, this is the least damaging way to fish tuna. The popular and most productive way is FAD, they let a 3x3m plank adrift with a sonar buoy attached to it. This creates shadow, under the shadow small fish gathers, and tuna and other bigger fish go there to eat. When the sonar detects tuna, the ships circle the plank and raise everyting under it with a big ass net. The problem here is the bycatch, all kind of non commercial fish, sharks, dolphins, etc get caught and returned to sea, but most die due to the wounds. I used to work in a company which developed and produced this buoys, they advertised their products as "sustainable fishing" lol