Lay nets are also known as gill nets. They can be hundreds of feet long and many feet deep with floats on the top edge and weights on the bottom. The problem with them is that, rather than targeting specific food fish, they can catch anything swimming by including turtles and monk seals. Because of this, they’re banned in certain areas, though not everywhere in Hawaii.
To me, this photo represents how the ban works. This section of the Kona coast is one of those areas where lay nets are banned. Someone has gone so far as to erect a sign in the lava near the coast. But that’s about it. In due course, the sign will fall down. It probably won’t be replaced. In the meantime, enforcement of the ban is spotty at best. Even when a violation is called in, chances are no one will be out to check on the situation until long after the net has been hauled and the netters gone home.