Patterns of vertical distribution and migration of zooplank− ton at Ocean Station “P

• Main Authors: Christopher J. -marlowe, Charles B. Miller
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1975
• Subjects: Pacific; Subarctic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.512.6177; http://www.aslo.org/lo/toc/vol_20/issue_5/0824.pdf

Stratified bongo net samples taken at depths between 0 and 500 m at Ocean Station “P” in the subarctic Pacific in early July 1971 have been analyzed to determine the vertical structure of the zooplankton community. Distributions for 99 categories of animals have been grouped by factor analysis into five basic patterns: surface dwellers, a bimodal sub-surface pattern, and three patterns of deep-dwelling forms with progressively deeper upper limits. Diurnal vertical migration was restricted to a very small fraction of the species present, primarily those previously described as strong migrators. The upward migration of some of these species stopped in the thermocline between 25 and 100 m. The minimum of biomass density found between 75 and 200 m by earlier workers was confirmed, and a similar minimunl was found in the distribution of a number of species. “Pattern ” is used in ecology to denote any recurring spatial arrangement of or-ganisms within their environments ( Elton 1966; Hutchinson 1952). A common pat-