Evidence for limited larval dispersal in black rockfish (Sebastes melanops): implications for population structure and marine-reserve design

Abstract

Although dispersal distances of marine larvae influence gene flow and the establishment of population structure, few data on realized dispersal distances exist for marine species. We combined otolith microstructure and micro chemistry of black rockfish (Sebastes melanops) to assess their potential to provide relative estimates of larval dispersal distance. In 2001 and 2002 we measured trace elements at discrete otolith regions, representing the (i) egg/early-larval, (ii) pelagic larval, and (iii) late-larval/early-juvenile periods of fish collected at three locations 120–460 km apart. Discriminant-function analyses based on geochemical signatures at each otolith region accurately grouped an average of 85% (jackknife = 67%) and 87% (jackknife = 81%) of the fish to collection location in 2001 and 2002, respectively. Age at collection ranged from 83 to 174 days and parturition dates within each site were spread over a 22- to 66-day period. Therefore, individuals within sites were not released at similar times. A probable explanation of these data is that larvae from different geographic locations did not mix during ontogeny and possibly did not disperse long distances alongshore. Larval dispersal distances may be appreciably shorter, <120 km, than previously assumed based on models of passive dispersal.

Large scale-variability in otolith microstructure and microchemistry: The case study ofDiplodus sargus sargus(Pisces: Sparidae) in the Mediterranean Sea

“…from the core, larval and juvenile regions (for a total of 324 replicate spots). The three replicates from the core were represented by three sequential pits (Miller & Shanks 2004;Patterson & Swearer 2007) vertically collected after having visually detected the core (Ruttenberg et al 2005(Ruttenberg et al , 2008. Each run generally consisted of 40 s acquisition: 10 s blank to correct for background, 10 s ablation resulting in a pit about 10 µm deep and 20 s for washout.…”

“…core, larval and juvenile regions) can be used to discriminate among groups of juveniles that use different locations, environments or habitats (e.g. lagoons, estuaries, open marine waters) during their ontogenetic development (Campana 1999;Miller & Shanks 2004).…”

“…A successful detection of locations of larval origin has been achieved for nesting species ). For species that spawn in open waters, instead, the identification of different groups of fishes has been used to infer about the spatial scales of larval dispersal and spatial heterogeneity of natal origin (Miller & Shanks 2004).…”

Local retention, dispersal and fluctuating connectivity among populations of a coral reef fish

“…This metric is much harder to estimate as it requires information about larval exchange among a network of populations. Few studies have tracked larval dispersal among populations (Miller and Shanks 2004;Becker et al 2007;Planes et al 2009;Shima and Swearer 2009); fewer still have empirically estimated temporal variation in dispersal (Miller and Shanks 2004); and none have empirically investigated the degree of temporal stability in connectivity among a network of populations.…”

Genetic structure and historical demography of the shanny Lipophrys pholis in the Portuguese coast based on mitochondrial DNA analysis

“…For reef Wshes, ecological evidence has demonstrated that passive dispersal alone cannot explain larval distributions (e.g., Leis and Carson-Ewart, 1998). Several studies have focused on early life-history traits (e.g., Doherty et al, 1995) and larval behaviour (e.g., Marliave, 1986;Miller and Shanks, 2004;Neilson and Perry, 1990) and tried to correlate them to dispersal potential. It would be interesting to understand if a coast with the range (ca.…”