The Guardian —
Baby sharks will emerge from their egg cases earlier and weaker as water temperatures rise, according to a new study that examined the impact of warming oceans on embryos.
About 40% of all shark species lay eggs, and the researchers found that one species unique to the Great Barrier Reef spent up to 25 days less in their egg cases under temperatures expected by the end of the century.
The extra heat caused embryonic epaulette sharks to eat through their egg yolks faster and when they were born, the rising temperatures affected their fitness.
“This is a huge red flag for us,” said Dr Jodie Rummer, an associate professor at the ARC Centre of Excellence for Coral Reef Studies at James Cook University and a co-author on the study.
Weaker sharks were less efficient hunters, Rummer said, which could then have a knock-on effect across the coral reefs where they live, upsetting the balance of the ecosystem.