Use of fish production per unit biomass ratios for measuring the productive capacity of fish habitats

• Published in: Canadian journal of fisheries and aquatic sciences 2000-08, Vol.57 (8), p.1657-1667
• Main Authors: Randall, R G, Minns, C K
• Format: Article
• Language: English
• Subjects: Freshwater; Osteichthyes
• ISSN: 0706-652X; 1205-7533
• DOI: 10.1139/cjfas-57-8-1657

Species-specific production rate per unit biomass (P/B, per year) ratios were calculated for 79 freshwater fish species of eastern Canada. P/B ratios were calculated using two methods, which were based on allometry with fish weight-at-maturity and life expectancy, respectively. P/B values obtained by the two methods were significantly correlated, as expected from life history theory, since the two predictors (longevity, size-at-maturity) were themselves correlated. Species-specific P/B ratios were also significantly correlated with field observations of P/B from published sources. The estimation of P/B based on allometry with fish size is recommended because of its utility; the predictive equation is P/B = 2.64W sub(mat) super(-0.35), where W sub(mat) is weight-at-maturity. Both the coefficient 2.64 and the exponent -0.35 of this equation are provisional and require further validation from field studies of fish production. More accurate estimates of P/B are possible if population-specific information on size-at-maturity or mean size is known. The product of average fish biomass and estimated P/B coefficients is a proposed measure of habitat productive capacity.