Snow and the Survival of Cod Fry

Abstract

IT has been a favourite idea with marine biologists in recent years that a connexion exists between the amount and timely efflorescence of plankton algæ and the success of propagation of certain sea fishes, the fry of which are directly or indirectly dependent upon the plankton algæ for their food. The correctness of this view has been demonstrated at least as regards the mackerel on the south coast of England by Prof. E. J. Allen, who traces the ultimate cause of the algal growth back to more or less abundant sunshine in the first months of the year. Prof. Gran has also shown that another influence must be at work to produce conditions more or less suitable for the development of plankton algæ, namely, the more or less plentiful amount of fresh water flowing into the sea and carrying with it from the land the salts and other substances necessary for plant life in the sea.