Does fishing dismantle fish culture and ecosystem structure? Questions about the implications of social learning among fish and fishers

Abstract

Scientific awareness of social learning, especially among vertebrates, has expanded rapidly in recent decades. That literature suggests that social learning may be a second adaptive mechanism that interacts with and refines genetic adaptation. For an individual fish, learning from others reduces the costs of acquiring experience-based behaviours and minimizes the hazards that arise from imperfect knowledge of local regularities. For a group of fish, social learning facilitates the evolution of time and place behaviours that work in its locality. It spreads those behaviours within the group and to subsequent generations. Thus, social learning enables persistent adaptation at a finer scale than might be possible through genetic processes alone. Strong evidence of genetic differentiation at less than a panmictic scale and persistent local depletions suggests regular, fine-scale system structure. Social learning may play an important role in creating and maintaining this finer-scale structure. Fishers' learned adaptations to the market and natural system usually lead them to target larger/older fish and fish aggregations at familiar times and places. However, older fish are likely to be the principal repository of the time-and-place experience required for local growth, survival, and reproduction, while social aggregations are important schools in which younger fish acquire the experience of older fish. Consequently, if adaptation through social learning is important among fish, there is reason to be concerned that heavy fishing of social learners reduces their abundance, as usually assumed, and impairs the inheritance of the socially learned experience required for persistent local adaptation.