Local biological drivers, not remote forcing, predict settlement rate to a subtropical barnacle population

Autor(es)

Barbosa, Andreia C. C. ; Gomes, Cristal C. ; Pereira, Gilberto C. ; Bueno, Marilia ; Flores, Augusto A. V.

• Tipo de documento: Artigo Científico
• Fonte: MARINE ECOLOGY-PROGRESS SERIES; v. 543, p. 8-pg., 2016-02-03.

Resumo

In spite of growing evidence for potential larval retention close to parental populations, it is still commonly assumed that large-scale transport mechanisms overwhelm local reproductive patterns and control larval settlement. Here, we evaluated the likelihood of settlement rate regulation by local biological factors and remote physical transport in a population of the intertidal tropical barnacle Chthamalus bisinuatus. Results indicated that juvenile recruitment and larval settlement may be substantially regulated by local reproductive output and pelagic food supply. Seasonal reproduction, with peak activity during summer, is followed by juvenile recruitment with no apparent lag over successive (ca. 15 d) sampling dates. Likewise, high-frequency (1 d) time-series analyses connected the main steps of the process: naupliar release correlates to cyprid supply in nearshore waters 7 d ahead, and cyprid supply is followed by larval settlement after an additional 4 to 5 d. Positive correlations between residuals of release vs. settlement relationships and chl a concentration (a proxy of phytoplankton biomass) also suggest food limitation for late naupliar stages. Tidal and wind transport did not explain the temporal variation in larval supply, and larval settlement responded only weakly to the wind of the day, suggesting a modest and very local effect. Addressing transport hypotheses alone is likely an inadequate approach to understand the supply-side ecology of marine invertebrates living in meso-oligotrophic systems such as the one examined in this study. A better understanding of processes affecting reproductive output and pelagic larval survival in addition to transport mechanisms, is likely required. (AU)

• Processo FAPESP: 13/01446-2 - Regulação trófica ascendente do recrutamento em invertebrados marinhos com desenvolvimento indireto: cracas como estudo de caso
• Beneficiário: Augusto Alberto Valero Flores
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 08/02030-6 - Importância relativa de processos físicos e biológicos na regulação do assentamento larval de cracas do entre-marés consolidado
• Beneficiário: Andreia Cristina Barbosa de Oliveira
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 08/10085-5 - Processos reguladores do assentamento larval, distribuição vertical, crescimento somático e rendimento reprodutivo de cracas do entre-marés rochoso
• Beneficiário: Augusto Alberto Valero Flores
• Modalidade de apoio: Auxílio à Pesquisa - Regular