Changes between Version 7 and Version 8 of EwEugConsumption
- Timestamp:
- 2010-11-24 21:05:04 (13 years ago)
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EwEugConsumption
v7 v8 15 15 The authors present three related models: 16 16 17 log(''Q/B'') = 7.964 - 0.204 log''W ,,∞,,'' - 1.965 .'' ''T' '' + 0.083 . ''A'' + 0.532 . ''h'' + 0.398 . ''d''''' Eq. 17'''17 log(''Q/B'') = 7.964 - 0.204 log''W[[Image(wiki:EwEugImages:Infinity_sub.png)]]'' - 1.965 .'' ''T' '' + 0.083 . ''A'' + 0.532 . ''h'' + 0.398 . ''d''''' Eq. 17''' 18 18 19 (R²=0.53, 98 df), where, ''W ,,∞,,'' is the asymptotic weight (g), ''T' '' is an expression for the mean annual temperature of the water body, expressed using ''T' '' = 1000/Kelvin (Kelvin = °C + 273.15), A is the aspect ratio (see Figure 2.1), ''h'' is a dummy variable expressing food type (1 for herbivores, and 0 for detritivores and carnivores), and ''d'' is a dummy variable also expressing food type (1 for detritivores, and 0 for herbivores and carnivores)19 (R²=0.53, 98 df), where, ''W[[Image(wiki:EwEugImages:Infinity_sub.png)]]'' is the asymptotic weight (g), ''T' '' is an expression for the mean annual temperature of the water body, expressed using ''T' '' = 1000/Kelvin (Kelvin = °C + 273.15), A is the aspect ratio (see Figure 2.1), ''h'' is a dummy variable expressing food type (1 for herbivores, and 0 for detritivores and carnivores), and ''d'' is a dummy variable also expressing food type (1 for detritivores, and 0 for herbivores and carnivores) 20 20 21 21 The equation was modified to investigate the effect on mortality on ''Q/B'', and to derive predictive models of ''Q/B'' taking explicit account of different mortalities, values of'' Q/B'' were calculated using the equation above for mortalities corresponding to ''f'' · ''M'', where ''f'' is a multiplicative factor with value of 0.5, 1, 2 or 4, and ''M'' is the natural mortality rate that is estimated from Pauly's (1980) empirical relationship. 22 22 23 log(''Q/B'') = 8.056 + 0.300log''f'' - 0.201 log''W ,,∞,,'' - 1.989 .'' ''T' '' + 0.081 . ''A'' + 0.522 . ''h'' + 0.393 . ''d ''''' Eq. 18'''''''23 log(''Q/B'') = 8.056 + 0.300log''f'' - 0.201 log''W[[Image(wiki:EwEugImages:Infinity_sub.png)]]'' - 1.989 .'' ''T' '' + 0.081 . ''A'' + 0.522 . ''h'' + 0.393 . ''d ''''' Eq. 18''''''' 24 24 25 25 (R²=0.52, 102 df), where ''f'' is the multiplicative factor introduces above, and the rest of the variables are as defined earlier. Note that in Palomares and Pauly (1998) Eq. 12, the sign for the ''T' '' factor was reversed by mistake. … … 27 27 For cases where an estimate of total mortality, ''Z'', (per year) is available the following relation may be used: 28 28 29 log(''Q/B'') = 5.847 + 0.280 log''Z'' - 0.152 log''W ,,∞,,'' - 1.360 .'' ''T' '' + 0.062 . ''A'' + 0.510 . ''h'' + 0.390 . ''d ''''' Eq. 19'''29 log(''Q/B'') = 5.847 + 0.280 log''Z'' - 0.152 log''W[[Image(wiki:EwEugImages:Infinity_sub.png)]]'' - 1.360 .'' ''T' '' + 0.062 . ''A'' + 0.510 . ''h'' + 0.390 . ''d ''''' Eq. 19''' 30 30 31 31 The models presented here updates the models derived from 33 empirical estimates of the consumption/biomass ratio (''Q/B'') for marine fishes, and published by the same authors in 1989.