. Bio-ecology. Plant ecology; Animal ecology; Botany; Ecology; Zoology. PELAGIC COMMUNITIES 317 habitant of shore vegetation, had a value of 25 (Shelford, 1918, a). Based on sulphur dioxide, the pelagic herring was rated at 10, the perch at 21, and the bottom flounder at 1100. Pelagic Communities of the North Atlantic The only modern consideration of pelagic communities in which the larger organisms and plankton are treated together as a unit is that represented by Murray and Hjort (1912:101-108; 617-704). M 150 500 1000 2000 3000 4000 5000 • Myctophum - Salpa Biome ^Scomber - Calanus^ / Biome
. Bio-ecology. Plant ecology; Animal ecology; Botany; Ecology; Zoology. PELAGIC COMMUNITIES 317 habitant of shore vegetation, had a value of 25 (Shelford, 1918, a). Based on sulphur dioxide, the pelagic herring was rated at 10, the perch at 21, and the bottom flounder at 1100. Pelagic Communities of the North Atlantic The only modern consideration of pelagic communities in which the larger organisms and plankton are treated together as a unit is that represented by Murray and Hjort (1912:101-108; 617-704). M 150 500 1000 2000 3000 4000 5000 • Myctophum - Salpa Biome ^Scomber - Calanus^ / Biome } Arevropelecus - Cauliodus Blome C. signata - A. purpurea Association 'iw '^<}^ C. microdon - A multispina ^ '%, Association. 40 50 60 Degrees - Latitude North 80 Fig. 73.—Diagrammatical vertical section of the North Atlantic with the several communities described by Murray and Hjort indicated, arranged so as to follow the practice in terrestrial communities. The depths to which the communities occur probably decrease from the equator to 60° N., owing to the difference in the penetration of solar radiation, but this is not indicated. These writers describe various communities of the pelagic waters of the North Atlantic which may perhaps be interpreted as biomes as suggested below. Furthermore, each appears divisible into two or more associations based upon the abundance of certain fishes and other larger animals that may be regarded as making the nearest ap- proach to dominants. The boundaries are apparently less definite than those between major land communities, but this is by no means certain, as the facts are much more difficult to ascertain. The ar- rangement of these (following IMurray and Hjort) is suggested in Fig. 73. While the small amount of observation renders the classifi- cation more or less hypothetical, it serves to illustrate probable. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readab
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Keywords: ., bookcentury1900, booksubje, booksubjectbotany, booksubjectzoology
