如何有效防止和避免化肥对人体危害（How to prevent and avoid the harm of chemical fertilizer to human body effectively）.doc

如何有效防止和避免化肥对人体危害（How to prevent and avoid the harm of chemical fertilizer to human body effectively） Four, the protection of fish resources Fish resources is the material basis of fishery production, and other biological resources must be utilized reasonably, in order to play its highest potential, if unrestricted fishing, so, fish resources would be destroyed. The breeding and conservation of fish are important measures of rational utilization of fish resources, fishery production is related to the development of the event, therefore, this problem has been paid more and more attention, through the understanding of fish patterns of life and the surrounding environment, to propose some effective measures to make the aquatic resources keep at a high level, truly inexhaustible and not the point. Effective reproductive protection is based on the biological basis of fish. Therefore, it is necessary to know in detail the breeding habits, the amount of eggs laid down and the physical and chemical factors of spawning sites. On the reproduction of protection measures are: (1) the provisions of fishing and fishing zones, in order to protect the parent fish breeding and larvae grow well, in their passing place and time, with some restrictions on fishing. (2) define fishing sizes and mesh sizes for the purpose of protecting immature juvenile fish so that they grow so as not to dry up resources. According to various fishing targets, the minimum size allowed for various fish is allowed to keep enough young fish to grow and breed as a standard. Net specification refers to the size of the net, fishing for different fish with different mesh sizes. (3) restriction and prohibition of fishing gear and fishing law. The fishing tackle and fishing methods which are harmful to fish resources shall be banned and banned (such as fried fish and tap work etc.). (4) on artificial seed and transplantation and acclimation and elimination of harmful organisms, its purpose is to increase fish speci