Sharks and Their Relatives: Ecology and ConservationIUCN, 1998 - 39 страница Sharks and their relatives, the rays and chimaeras, are the diverse group of cartilaginous fishes that have evolved over 400 million years. Historically considered of low economic value to large-scale fisheries, today many of these fishes have become the target of directed commercial and recreational fisheries around the world, and they are increasingly taken in the by-catch of fisheries targeting other species. This report emphasizes the widely-acknowledged need to improve shark fishery monitoring, expand biological research and take management action. It serves as an introduction to the ecology, status and conservation of the sharks and their relatives for a general audience. Shark fisheries can only be managed sustainably, and shark populations remain viable, with the introduction of new conservation and management initiatives. |
