Comparative analysis of phylogenetic and fishing effects in life history patterns of teleost fishes

Abstract

Comparative analysis of phylogenetic and fishing effects in life history patterns of teleost fishes. -Oikos 91: 255 -270.The effects of fishing on life history traits and life history strategies of teleost fishes are analysed by a new comparative method that splits traits into an allometric part (size effect), an autoregressive phylogenetic component, and an environmental component (fishing effect). Both intra-and inter-specific variation of age and size at maturity, fecundity, adult size and egg size are analysed by comparing 84 populations of 49 species submitted to various fishing pressures. Two axes of life history diversification are found among teleosts. One is the well-known slow-fast continuum separating short-lived and early maturing species (like Clupeiformes) from longerlived species that mature late relative to their size and spawn larger eggs (like salmonids or Scorpaeniformes). An additional strategy involves the schedule of resource allocation to growth and reproduction. Indeterminate growth allows higher teleosts (e.g. Gadiformes) to reach a large size while maturing early and laying small eggs. Increasing fishing pressure decreases age at maturity and egg size, and increases fecundity at maturity, the slope of the fecundity-length relationship and relative size at maturity. These compensations for higher adult mortality differ among life history strategies. Indeterminate growth is associated with a greater flexibility in resource allocation to growth and reproduction that facilitates greater resilience to fishing mortality.M.-J. Rochet,

Fish condition in introduced tilapias of Ugandan crater lakes in relation to deforestation and fishing pressure

“…Ricker 1981;Grift et al 2002;Olsen et al 2004Olsen et al , 2005. It is often assumed that fishing-induced reductions in population density of target stock lead to increased yield because of reduction in intraspecific competition that releases populations from density-dependence resulting in faster growth and earlier maturation (Jennings and Kaiser 1998;Hall 1999;Law 2000;Rochet et al 2000). A reduction in intraspecific competition is also likely to foster better fish condition.…”

Fisheries-induced trends in reaction norms for maturation in North Sea plaice

“…A second important advantage of the method is that it cleanly separates changes in growth and survival from a description of the maturation process. Some previous empirical studies attempted to separate growth from the maturation process (Hutchings 1993b, a, Rijnsdorp 1993a, Rowell 1993, Rochet et al 2000, but could not conclusively disentangle these aspects. Maturity ogives do not distinguish between first-time spawners and repeat spawners and are influenced by maturation probabilities but also by mortality rates and growth rates (Heino et al 2002a).…”

Long-term changes in maturation of sardine, <i>Sardina pilchardus</i>, in Portuguese waters

“…Increased water temperature may induce maturation at a younger age by increasing the growth rate (Sinclair et al 2002) or even independently of growth (Dhillon andFox 2004, Tobin andWright 2011). Increased food availability may have a similar effect since it usually leads to higher growth and improved body condition (Rochet et al 2000;Kuparinen and Merilä 2007). Higher food availability per capita may be a direct response to the physical environment (e.g.…”

“…If mostly small and young fish contribute to reproduction, maturation age and size are expected to decline and other life-history traits with strong size/age-dependency, such as fecundity and egg and larval survival may decrease, magnifying abundance fluctuations and susceptibility to over-fishing (Rochet et al 2000, Kuparinen and Merilä 2007, Anderson et al 2008. The persistence of fishing effects may lead to evolutionary changes in life-history traits at decadal time scales, with important consequences for the dynamics of exploited populations (Law 2000, Jørgensen et al 2007, Kuparinen and Merilä 2007, Allendorf et al 2008.…”