Some basic problems in the Antarctic krill population
Noting biomass, annual growth-rate, carrying capacity, annual consumption rate by Antarctic animals such as whales and seals and annual catching rate by mankind of Antarctic krill by Z, p, Z_∞, R and F_k respectively, a time-change rate of Z is simply expressed by dZ/dt=pZ(1-Z/Z_∞)-(R+F_k) The criti...
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National Institute of Polar Research
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fttriple:oai:gotriple.eu:oai:doaj.org/article:ed89f8046b4c42d390b0f2d9fa345586 2023-05-15T13:32:55+02:00 Some basic problems in the Antarctic krill population Takesi Nagata 1983-09-01 https://doi.org/10.15094/00008366 https://doaj.org/article/ed89f8046b4c42d390b0f2d9fa345586 en other eng National Institute of Polar Research doi:10.15094/00008366 0085-7289 2432-079X https://doaj.org/article/ed89f8046b4c42d390b0f2d9fa345586 undefined Antarctic Record, Iss 79, Pp 42-54 (1983) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 1983 fttriple https://doi.org/10.15094/00008366 2023-01-22T19:30:42Z Noting biomass, annual growth-rate, carrying capacity, annual consumption rate by Antarctic animals such as whales and seals and annual catching rate by mankind of Antarctic krill by Z, p, Z_∞, R and F_k respectively, a time-change rate of Z is simply expressed by dZ/dt=pZ(1-Z/Z_∞)-(R+F_k) The critical condition for not resulting in a catastrophic vanishment of Z is given by (R+F_k)≦pZ_∞/4 and Z≧(Z_∞-Q)/2,where Q≡Z_∞[1-4(R+F_k)/pZ_∞]^. The most plausible numerical values of p, Z_∞, and R at present will be p=1.0 (year)^, Z_∞=(10)^9 tons and R=1.1×(10)^8 tons/year. If so, F_k<1.1×(10)^8 tons/year will be the allowable upper limit for the krill catching at present. In such a case, however, an increase of whale biomass may not be expected. If F_k is considerably smaller than the critical value for (R+F_k), an increase of whale biomass can be expected. Article in Journal/Newspaper Antarc* Antarctic Antarctic Krill Unknown Antarctic The Antarctic |
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language |
English |
topic |
geo envir |
spellingShingle |
geo envir Takesi Nagata Some basic problems in the Antarctic krill population |
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geo envir |
description |
Noting biomass, annual growth-rate, carrying capacity, annual consumption rate by Antarctic animals such as whales and seals and annual catching rate by mankind of Antarctic krill by Z, p, Z_∞, R and F_k respectively, a time-change rate of Z is simply expressed by dZ/dt=pZ(1-Z/Z_∞)-(R+F_k) The critical condition for not resulting in a catastrophic vanishment of Z is given by (R+F_k)≦pZ_∞/4 and Z≧(Z_∞-Q)/2,where Q≡Z_∞[1-4(R+F_k)/pZ_∞]^. The most plausible numerical values of p, Z_∞, and R at present will be p=1.0 (year)^, Z_∞=(10)^9 tons and R=1.1×(10)^8 tons/year. If so, F_k<1.1×(10)^8 tons/year will be the allowable upper limit for the krill catching at present. In such a case, however, an increase of whale biomass may not be expected. If F_k is considerably smaller than the critical value for (R+F_k), an increase of whale biomass can be expected. |
format |
Article in Journal/Newspaper |
author |
Takesi Nagata |
author_facet |
Takesi Nagata |
author_sort |
Takesi Nagata |
title |
Some basic problems in the Antarctic krill population |
title_short |
Some basic problems in the Antarctic krill population |
title_full |
Some basic problems in the Antarctic krill population |
title_fullStr |
Some basic problems in the Antarctic krill population |
title_full_unstemmed |
Some basic problems in the Antarctic krill population |
title_sort |
some basic problems in the antarctic krill population |
publisher |
National Institute of Polar Research |
publishDate |
1983 |
url |
https://doi.org/10.15094/00008366 https://doaj.org/article/ed89f8046b4c42d390b0f2d9fa345586 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Antarctic Krill |
genre_facet |
Antarc* Antarctic Antarctic Krill |
op_source |
Antarctic Record, Iss 79, Pp 42-54 (1983) |
op_relation |
doi:10.15094/00008366 0085-7289 2432-079X https://doaj.org/article/ed89f8046b4c42d390b0f2d9fa345586 |
op_rights |
undefined |
op_doi |
https://doi.org/10.15094/00008366 |
_version_ |
1766037024832225280 |