New research shows newborn sharks have short stature, weak physique, and lack of nutrition compared to before. The reason is attributed to climate change.
This is a small, spawning shark commonly found in the Great Barrier Reef. They spend most of their time on the seabed.
Taking the shark egg sac for examination in the lab, the scientists found that hot water can cause sharks to be born prematurely.
Lead author of the study, Dr. Carolyn Wheeler – at the University of Massachusetts, USA – explains that the warmer the environment, the faster certain reproductive processes occur.
Embryos develop faster and use nutrients from the yolk sac faster. It is the only food source for baby sharks when they grow up in eggs.
So when nutrients disappear early, the eggs may hatch earlier than usual. The specific reason for this phenomenon is not clear.
Usually, sharks have two modes of reproduction: laying eggs and laying eggs. Bigger sharks like white shark, whale shark … will give birth, while small shark usually lays eggs. Most eggs hatch and develop on their own without parental help.
For laying sharks, being young and weak is very detrimental.
The discovery is of concern to all sharks, researchers say. Dr Jodie Rummer – marine biologist at James Cook University (Australia) and study co-author – Shoulder sharks are often very adaptable to change. Therefore, if this species is also unable to cope with warmer waters, then the less tolerant species will be in danger.
In addition, sharks are an important link in marine ecosystems. According to Toby Daly-Engel – director of the laboratory for shark conservation at Florida University of Technology (USA), if the sharks disappear, the small population of fish will explode because no species can eat them.
Soon after, their food is plankton, microorganisms and small shrimp will all be depleted. In the end, it is these little fish that will starve to death.
The team continued to test the effects of warm seawater temperatures on Epaulette shark eggs. This time the team started watering at 31 ° C – the expected summer temperature for the Great Barrier Reef in 2100.
As a result, the reproductive process is not the same process as before. If temperatures continue to rise, more ocean ecosystems could be in trouble, the team warns.
