http://www.tidalropes.com/traw... Please note these are for middle & high depths
http://www.nichimo-marine.jp/p... Note the chart lists depth, weight & bouyancy figures
Never the less, these are "termed" floats by the trawler industry. They are floats because the DO float at SOME depth. Not all nets have floats on the top line that FLOAT ABOVE the water. It depends on what level the fish are. One might want the net to begin at 30' depth and end at 60' depth. I would suspect that the "ears" are for very quick connect attachment rigs to the net so they can be easily changed to change the depths the net is to drag.
FYI, one of the definitions of trawl
a large wide-mouthed fishing net dragged by a vessel along the bottom or in the midwater of the sea or a lake. NOTE it states bottom or midwater
