Trophic Efficiency Facilitates Larval Shortbelly Rockfish (Sebastes jordani) Development

Abstract

Identifying the factors influencing fish recruitment is critical for fishery management, and failure to do so can have major ecological and economic consequences. Many hypotheses over the past century have been proposed, and the recently postulated Trophic Efficiency in Early Life (TEEL) hypothesis argues that a shorter food chain length can result in more efficient energy transfer from primary producers to young fishes, thereby increasing growth rate and larval condition, reducing early-life mortality and ultimately leading to a stronger recruitment cohort. To test this hypothesis, we analyzed the trophic position (TP) through compound-specific isotopic analysis of amino acids, as well as otolith microstructure and stomach content of larval shortbelly rockfish (Sebastes jordani). Results show larval rockfish that ate lower TP prey were both heavier and faster growing. This suggests the trophic characteristics of early life diet are critical to larval survival, and provide evidence in support of the TEEL hypothesis.