Historical anchored (Type A) tags were associated with negative effects on North Atlantic right whale survival and reproduction

Tagging data can provide critical information to support the conservation of marine mammal species, but these benefits must be balanced against any potential adverse effects on the health and vital rates of tagged individuals, particularly in endangered populations. Data from historical tag deployments can be used to evaluate these effects. Here, we expand a model for the Population Consequences of Multiple Stressors to investigate the effects of invasive tags deployed from the late 1980s through 2001 on the health, survival and reproduction of critically endangered North Atlantic right whales (Eubalaena glacialis). Historical tags deployed on this species include anchored (Type A) tags and consolidated (Type C) tags. The effects of these deployments were explored alongside the effects of other stressors included in the model (entanglements, vessel strikes and prey abundance). Our results indicate that historical anchored (Type A) tags had a negative effect on the health of tagged individuals, which is linked in the model with their survival and calving probabilities. We found limited evidence in additional exploratory analyses that confounding factors may have affected our findings. In contrast, we did not detect any effect of historical consolidated (Type C) tags. This study demonstrates the utility of our modelling approach for assessing the effects of invasive tagging on the survival and reproduction of tagged individuals. The model could be used to explore the effects of future deployments on this critically endangered species, contributing to improve tag design and inform future permitting decisions.