TORONTO – A new study has found that warming oceans are giving birth to smaller and malnourished sharks, making it difficult for them to survive.
The study, conducted by researchers at the ARC Center of Excellence for Coral Reef Studies at James Cook University in Australia, found that as climate change continues to warm the world’s oceans, baby sharks emerge from their eggs earlier, making them weak and exhausted.
“The warmer the conditions, the faster everything went, which could be a problem for the sharks. The embryos grew faster and used their yolk sac faster, which is their only food source as they develop in the egg. outbreak earlier than usual, ”said lead author and doctoral candidate Carolyn Wheeler in a press release.
The findings, published Tuesday in the peer-reviewed journal Scientific Reports, examined the impact of increased water temperature on the growth, development and physiological performance of epaulette sharks up to 31 ° C. .
According to the study, epaulet sharks are a laying species that can only be found on the Great Barrier Reef. Researchers studied sharks as embryos and later as newborns.
The study found that the newborns were not only smaller, but had to feed almost immediately because they lacked “significant energy.”
Co-author and associate professor Jodie Rummer said in the statement that this makes it difficult for the species to survive because epaulette sharks don’t care about their eggs after they spawn. She said that means a shark egg must survive “unprotected for up to four months” on its own.
Rummer said rising ocean temperatures are a “major concern for the future of all sharks,” including laying and living species.
“The epaulette shark is known for its resilience to change, even to ocean acidification. So if this species cannot cope with warming waters, how will other less tolerant species behave? Rummer said.
Rummer added that the waters of the Great Barrier Reef will “likely” experience average temperatures “near or even above” 31 ° C by the end of the century.
The study suggests that sharks will be born or hatch in environments that are already at the hottest temperature they can tolerate, reducing their chances of survival.
Wheeler says the results are worrying given that shark species are “already threatened” across the world.
According to the study, sharks are “slow growing” creatures that do not reproduce as often as other fish, which contributes to their decline.
“Sharks are important predators that maintain the health of ocean ecosystems. Without predators, entire ecosystems can collapse, which is why we must continue to study and protect these creatures, ”Wheeler said in the statement.
Rummer added that future ocean ecosystems “depend on [on] we are taking urgent action to limit climate change “to protect sharks and other aquatic species.”