Shoal size as a key determinant of vulnerability to capture under a simulated fishery scenario. Issue 13 (11th June 2018)

• Record Type: Journal Article
• Authors: Thambithurai, Davide; Hollins, Jack; Van Leeuwen, Travis; Rácz, Anita; Lindström, Jan; Parsons, Kevin; Killen, Shaun S.
• Is Part Of: Ecology and evolution. Volume 8:Issue 13(2018)
• Page Start: 6505
• Page End: 6514
• Publication Date: 2018-06-11
• Subjects: collective behavior -- evolutionary trap -- fisheries‐induced evolution -- metabolic rate -- sociality; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.4107
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Group living is widespread among animals and has a range of positive effects on individual foraging and predator avoidance. For fishes, capture by humans constitutes a major source of mortality, and the ecological effects of group living could carry‐over to harvest scenarios if fish are more likely to interact with fishing gears when in social groups. Furthermore, individual metabolic rate can affect both foraging requirements and social behaviors, and could, therefore, have an additional influence on which fish are most vulnerable to capture by fishing. Here, we studied whether social environment (i.e., social group size) and metabolic rate exert independent or interactive effects on the vulnerability of wild zebrafish ( Danio rerio ) to capture by a baited passive trap gear. Using video analysis, we observed the tendency for individual fish to enter a deployed trap when in different shoal sizes. Fish in larger groups were more vulnerable to capture than fish tested individually or at smaller group sizes. Specifically, focal fish in larger groups entered traps sooner, spent more total time within the trap, and were more likely to re‐enter the trap after an escape. Contrary to expectations, there was evidence that fish with a higher SMR took longer to enter traps, possibly due to a reduced tendency to follow groupmates or attraction to conspecifics already within the trap. Overall, however, social influences appeared to largely overwhelm any link between vulnerability and metabolic rate. The results suggest that group behavior, which in a natural predation setting is beneficial for avoiding predators, could be maladaptive under a trap harvest scenario and be an important mediator of which traits are under harvest associated selection. Abstract : Anthropogenic harvest has the capacity to shape the evolution of wild organisms. Here, we tested how shoal size and metabolism interact to shape capture vulnerability in fish within a simulated human harvest scenario. Our study provides new insight for understanding the relationships between physiology, behaviour, and human‐induced selection.