Warming of oceans due to Climate change is leaving baby sharks not only smaller, exhausted, undernourished but also making their survival tough, a study published in the journal Scientific Reports has warned, painting gloomy picture for marine world as temperatures underwater is predicted to exceed in the coming years.
Researchers reached to this conclusion after testing the growth, development and physiological performance of embryos and hatchlings of epaulette sharks--an egg-laying species at the New England Aquarium in waters up to 31 degrees Celsius (87.8 degrees) Fahrenheit.
Lead author Carolyn Wheeler a PhD scholar from the University of Massachusetts Boston and at the ARC Centre of Excellence for Coral Reef Studies at James Cook University, studied the sharks as embryos and hatchlings, under the guidance of Dr John Mandelman, Vice President and Chief Scientist of the Anderson Cabot Center for Ocean Life at the New England Aquarium.
There are more than 500 types of shark living around the world, and the majority give birth to live young. Some shark species, like epaulette sharks, lay eggs, which are left unprotected and must be able to survive on their own for up to four months.
"We found that the hotter the conditions, the faster everything happened, which could be a problem for the sharks," said Wheeler. "The embryos grew faster and used their yolk sac quicker, which is their only source of food as they develop in the egg case. This led to them hatching earlier than usual." Wheeler said the hatchlings were not only smaller, but they needed to feed almost immediately while lacking significant energy.
"The ocean faces increasing threats from humans, such as the effects of climate change, and it is vital to conduct scientific research to help strengthen the management and protection of those ocean species most negatively impacted and vulnerable," Mandelman said. "In this case, we addressed a pressing threat--ocean warming--and the potential impacts on a species that could serve as a model for other egg laying species among sharks and their relatives."
"The epaulette shark is known for its resilience to change, even to ocean acidification," Jodie Rummer, co-author and associate professor at the ARC Centre of Excellence for Coral Reef Studies, said in a statement. "So, if this species can't cope with warming waters, then how will other, less tolerant species fare?"
The Aquarium has a successful breeding program for epaulette sharks, allowing the researchers to use some of the eggs to study climate change impacts on a shark species native to the other side of the world. The research was housed at the Aquarium's Animal Care Center in Quincy, Mass. under the direction of Barbara Bailey, Curator of Husbandry and Sustainability, informed the study.
