Landings of the spurdog, Squalus acanthias, at Mevagissey reflect the changes in phosphate at the neighbouring International Hydrographic Station Ei.It is suggested that commercial landings of rays and skates ought to follow major changes in nutrient content of the overlying water with a time lag of some years. Fishery statistics for English Channel ports support this view. The dependence of the bottom in-fauna upon the fertility of the overlying water is also discussed.Proposals to improve commercial fisheries by artificially fertilizing considerable areas of the open sea are critically examined. Such artificial enrichment is considered to be grossly uneconomic unless fishing becomes pisciculture in which weeding of unwanted algae and control of unwanted pests—competing predators and parasites—is undertaken.

中文翻译：

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磷酸盐和渔业

马刺的着陆，角鲨，在 Mevagissey 反映了邻近国际水文站 Ei 的磷酸盐变化。建议商业登陆鳐鱼和鳐鱼应该跟随上覆水的营养成分的重大变化，并有几年的时间滞后。英吉利海峡港口的渔业统计数据支持这一观点。还讨论了底部动物群对上覆水域肥力的依赖性。通过对公海相当大的区域进行人工施肥来改善商业渔业的建议进行了严格审查。这种人工富集被认为是非常不经济的，除非渔业变成养鱼业，在这种养鱼业中除草不需要的藻类和控制不需要的害虫——竞争捕食者和寄生虫——进行。