Fitness consequences of fish circadian behavioural variation in exploited marine environments

Abstract

The selective properties of fishing that influence behavioural traits have recently gained interest. Recent acoustic tracking experiments have revealed between-individual differences in the circadian behavioural traits of marine free-living fish; these differences are consistent across time and ecological contexts and generate different chronotypes. Here, we hypothesised that the directional selection resulting from fishing influences the wild circadian behavioural variation and affects differently to individuals in the same population differing in certain traits such as awakening time or rest onset time. We developed a spatially explicit social-ecological individual-based model (IBM) to test this hypothesis. The parametrisation of our IBM was fully based on empirical data; which represent a fishery formed by patchily distributed diurnal resident fish that are exploited by a fleet of mobile boats (mostly bottom fisheries). We ran our IBM with and without the observed circadian behavioural variation and estimated selection gradients as a quantitative measure of trait change. Our simulations revealed significant and strong selection gradients against early-riser chronotypes when compared with other behavioural and life-history traits. Significant selection gradients were consistent across a wide range of fishing effort scenarios. Our theoretical findings enhance our understanding of the selective properties of fishing by bridging the gaps among three traditionally separated fields: fisheries science, behavioural ecology and chronobiology. We derive some general predictions from our theoretical findings and outline a list of empirical research needs that are required to further understand the causes and consequences of circadian behavioural variation in marine fish.

Netting the Stress Responses in Fish

“…Cortisol has been shown to induce the expression of per1a and per1b and repress bma11a and clock genes that control circadian rhythms in fish, and it has been proposed to act as a modulator of molecular oscillators (19, 96). Molecular clocks that respond to environmental factors such as light and dark cycles, food availability and thermal conditions vary both in natural and in HIREC environments and may contribute to the ticking of stressomes in a set of defined stressotopes involving migration and breeding scenarios (97).…”

Aggressiveness-related behavioural types in the pearly razorfish

“…Fish vulnerability to fishing is a complex phenomenon in which many processes are involved, and in which behaviour plays a significant role ( Arlinghaus et al, 2017 ). It has been demonstrated that fishers select for certain behaviours (activity, awakening time) in wild pearly razorfish populations ( Alós et al, 2016 ; Martorell-Barceló, Campos-Candela & Alós, 2018 ). In other species, fishing selects against bold and aggressive individuals ( Arlinghaus et al, 2017 ).…”

Contrasting the Motivations and Wildlife-Related Value Orientations of Recreational Fishers With Participants of Other Outdoor and Indoor Recreational Activities

“…In fact, recreational anglers were found to be overwhelming pluralists, i.e., they not only care for their catch but also perceive wildlife and fish as to be deserved for caring and protection. However, as RF is a consumptive activity, in certain situations it can produce a high level of exploitation of fish resources (Alós et al, 2012(Alós et al, , 2016Martorell-Barceló et al, 2018). Thus, proper management of the activity is necessary to maintain both the biological productivity of the exploited stocks considering the social and cultural dimension of RF in Spain.…”