NOTES AND LITERATURE 



VALUATION OF THE SEA 1 



It is very interesting to see a small country like Denmark lead 

 so prominently in several lines of ecologic study. The nestor of 

 plant ecologists, Warming, has done his work here. The ecology 

 of fresh-water animals, particularly the plankton, has been stud- 

 ied by Wesenberg-Lund; the marine animals have been persist- 

 ently studied by Dr. C. G. Joh. Petersen, and the ecological in- 

 terrelations of the vegetation and the animals (particularly the 

 fish) have been studied recently by the plant ecologist Ostenfeld. 

 And although this is not all that has been done, it shows very 

 clearly the network of problems on sea and land which has been 

 studied from a modern ecological standpoint. 



The paper now under consideration is one of the latest ecolog- 

 ical contributions to a study of the conditions of life upon the 

 sea bottom. The senior author, Dr. Petersen, has been at work 

 on these problems since 1883. This long interval affords him a 

 splendid opportunity to observe the character of the changes on 

 the sea bottom. He says: "The impression of the fauna as a 

 whole remains, however, unchanged within such a short period of 

 time as one generation. This holds good for the Kattegat and 

 the Baltic, thus for comparatively open and large stretches of 

 water." Through his studies of the fishes, particularly the 

 plaice, he came to the conclusion that, "To understand the dis- 

 tribution of animals right on the bottom, we must study the oc- 

 currence of each species throughout the whole of its life." When 

 he learned that the plaice from the western part of Limfjord 

 were inhibited in growth for 8 months, but when transported to 

 its central part they increased four to five times their original 

 weight, he concluded that serious attention must be given to their 

 food. The cause for this difference he thought was due to the 

 relative amounts of food present— but how was this to be deter- 

 mined? This led to a long series of experiments in methods of 



l " Valuation of the Sea. I. Animal Life of the Sea-Bottom, Its Food 

 and Quantity" (quantitative studies). By C. G'. Joh. Peterson and P. 

 Boysen Jensen. Beport of the Danish Biological Station to the Board of 

 Agriculture, Vol. XX, pp. 1-76, Plates VI, 1911. Translated from < ' Fiskeri- 

 Beretning for 1910." Copenhagen. 



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