Tag attachment success can be temperature dependent: A case study of the chub mackerel Scomber japonicus

Abstract

Background: Electronic tags are increasingly used in the studies of fish, but the attachment of electronic tags may affect their behaviour and physiology. While a number of studies have shown effects of electronic tags on fish health and behaviour, few have examined the effects of thermal conditions on the consequences of electronic tagging. In the present study, we conducted two laboratory experiments under two different water temperatures (22.5 ± 1.5 and 12.7 ± 1.8 °C) to evaluate the growth and survival of commercially reared chub mackerel Scomber japonicus tagged with a dummy electronic tag. Results: The presence of the tag, but not the surgical operation itself, significantly decreased fish survival rate under warm conditions, whereas high survival rates (ca. 96 %) were observed for both tagged and untagged fish under cold conditions. No difference in growth rate was found between the tagged and untagged fish under cold conditions, but tagged fish grew more poorly than untagged fish under warm conditions. Conclusions: Our result showed that water temperature clearly affects the impact of tagging on the health of commercially reared chub mackerel.