| 要旨トップ | 目次 | 日本生態学会第59回全国大会 (2012年3月,大津) 講演要旨
ESJ59/EAFES5 Abstract


一般講演(ポスター発表) P2-182A (Poster presentation)

Life history traits and fishery impact on fishes’ variance-mean relationship

KUO, T.C.*, Hsieh, C.H.

A power-law relationship between population variance and mean abundance, V=aMb, is commonly observed in ecology. Many factors have been proposed to influence ‘b’, such as aggregation degree, growth rate, and reproduction, although the interpretation of the intercept ‘a’ remains elusive. In this study, we estimated the spatial variance-mean relationship of 29 fish species collected from the southern California Current Ecosystem spanning from 1951-2007. We investigated whether the exponent ‘b’ and intercept ‘a’ is related to life history traits of fishes. In addition, we examined the fishing impacts by comparing exploited versus unexploited species, accounting for life history variation using a generalized linear model. We found that after removing the influence of mean abundance, all life history traits play a significant role in determining the exponent. Moreover, the relationship between the exponents and life history traits of exploited species is significantly weaker than that of the unexploited species. Our results suggest that fishing may change the exponent of a species through changing their life history traits, such as maximum length and maturation age. Thus, the exploited species may have a higher variance in spatial distribution than an unexploited species with the same abundance and recorded life traits.


日本生態学会