The drag-net fishery of California accounts for most of the production of fresh fish for the northern and central California markets. This fishery, which is carried on almost entirely by “paranzella” drag nets, produces about twelve million pounds of fish a year, of which 75 per cent are various flounders that inhabit the waters along the California coast. Because of the tremendous waste of small unmarketable fish, due to the small-sized mesh in the drag nets, an investigation was inaugurated to test the escapement alive of different sized fish through various sizes of mesh, and likewise to measure the effectiveness of the escapement of fish through different parts of both experimental and commercial drag nets. It was found, that by increasing the size of mesh in the sacks or cod-ends of these drag nets, a large percentage of the small unmarketable and immature fish was permitted to escape alive, without reducing the total catch of marketable fish. The drag-net industry in California voluntarily adopted the recommendations for the enlargement of mesh sizes and is now enjoying greater catches per unit of effort.