Scaling of Activity Space in Marine Organisms across Latitudinal Gradients

Unifying models have shown that the amount of spaceused by animals (e.g., activity space, home range) scales allometricallywith body mass for terrestrial taxa; however, such relationships arefar less clear for marine species. We compiled movement data from1,596 individuals across 79 taxa collected using a continental passiveacoustic telemetry network of acoustic receivers to assess allometric scal-ing of activity space. We found thatectothermic marine taxa do exhibitallometric scaling for activity space, with an overall scaling exponentof 0.64. However, body mass alone explained only 35% of the varia-tion, with the remaining variation best explained by trophic positionfor teleosts and latitude for sharks, rays, and marine reptiles. Taxon-specific allometric relationships highlighted weaker scaling exponentsamong teleostfish species (0.07) than sharks (0.96), rays (0.55), andmarine reptiles (0.57). The allometric scaling relationship and scalingexponents for the marine taxonomic groups examined were lowerthan those reported from studies that had collated both marine andterrestrial species data derived using various tracking methods. Wepropose that these disparities arise because previous work integratedsummarized data across many studies that used differing methods forcollecting and quantifying activity space, introducing considerableuncertainty into slope estimates. Ourfindings highlight the benefitof using large-scale, coordinated animal biotelemetry networks to ad-dress cross-taxa evolutionary and ecological questions