Ontogeny and ecological significance of metabolic rates in sea turtle hatchlings

Abstract

Background Sea turtle hatchlings must avoid numerous predators during dispersal from their nesting beaches to foraging grounds. Hatchlings minimise time spent in predator-dense neritic waters by swimming almost continuously for approximately the first 24 h post-emergence, termed the ‘frenzy’. Post-frenzy, hatchling activity gradually declines as they swim in less predator-dense pelagic waters. It is well documented that hatchlings exhibit elevated metabolic rates during the frenzy to power their almost continuous swimming, but studies on post-frenzy MRs are sparse. Results We measured the frenzy and post-frenzy oxygen consumption of hatchlings of five species of sea turtle at different activity levels and ages to compare the ontogeny of mass-specific hatchling metabolic rates. Maximal metabolic rates were always higher than resting metabolic rates, but metabolic rates during routine swimming resembled resting metabolic rates in leatherback turtle hatchlings during the frenzy and post-frenzy, and in loggerhead hatchlings during the post-frenzy. Crawling metabolic rates did not differ among species, but green turtles had the highest metabolic rates during frenzy and post-frenzy swimming. Conclusions Differences in metabolic rate reflect the varying dispersal stratagems of each species and have important implications for dispersal ability, yolk consumption and survival. Our results provide the foundations for links between the physiology and ecology of dispersal of sea turtles.

DNA methylation carries signatures of sublethal effects under thermal stress in loggerhead sea turtles

“…Noteworthy, numerous studies have shown similar effects of incubation temperature on other physiological and performance traits in other sea turtle species (e.g. Howard et al 2014;Gatto et al, 2022).…”

Short‐term resilience to climate‐induced temperature increases for equatorial sea turtle populations

“…Porter et al (2021) showed that from a sample of four green turtle clutches (PT = 28.1°C), one clutch had a much greater propensity to produce males, even producing some males at a typical female‐producing incubation temperature. So, there may be limited avenues for turtles to adapt fully to climate warming, prompting concerns that direct intervention may be required at many sites (including the Conflict Islands Group) to promote greater male hatchling production (Gatto et al, 2021; Smith et al, 2021).…”