Climate change is affecting shark pups

Shark pups do not reach their full physical potential in environments impacted by human-induced factors such as the climate crisis, according to a study. Jodie Rummer and her colleagues at the James Cook University in Australia compared the foraging behaviour and health conditions of newborn reef shark populations in two places.

One was St Joseph, an uninhabited, remote and small atoll in the outer islands of Seychelles — a country in East Africa in the Indian Ocean — where no environmental changes happened at the time of the study. Another was Moorea, a popular tourist destination in French Polynesia and a place that is still recovering from a loss of up to 95 per cent of its live coral cover from about five years before the study started.

The researchers captured and measured a total of 546 young sharks during the four year period of the study, and found that the amount of fat reserves the pups had varied between the locations. According to the study, published in the journal Scientific Reports, even if the shark pups are born larger, heavier, and better conditioned in Moorea, they lost their physical advantage over the pups in St Joseph.

“At birth, newborn sharks receive extra fat reserves from their mother,” said Ornella Weideli, lead author of the study and PhD student at the Centre de Recherches Insulaires et Observatoire de l'Environnement (CRIOBE) in France. Weideli added that the fat reserves helped the pups sustain during the first days and weeks after birth.