CALDERA – Great white sharks might have been a lot more plentiful along Chile’s Pacific coast 5.3 to 2.5 million years ago. The evidence for this is an ancient shark nursery discovered in the Coquimbo coastal region and a rich fossil record of adult sharks near modern-day Caldera. This information can be used to help conserve the species and it might also help predict where shark nurseries will show up next if climate change warms historically colder coastal waters.
The results of a shark teeth fossil record investigation published May 22 in Scientific Reports strongly suggest that a large population of great white sharks lived and flourished in the waters off Coquimbo and Caldera for millions of years.
The report also suggests that Coquimbo was an important nursery for great white sharks in the Pliocene era, 5.3 to 2.5 million years BP, just before the appearance of humans on earth. The shallow-water conditions off the Coquimbo coast would have been favorable to juveniles and pups. Abundant food was also available for shark pups as evidenced by the presence of fossils of small fish species and typical marine invertebrates and vertebrates that prefer shallow-water habitats.
Caldera waters, on the other hand, might have served as a feeding territory for the mature adults, due to the presence of fossils of their prey, such as dolphins and whales. The deep-water conditions and evidence of other predator shark species in the Caldera region also suggests the location was more of an “adult-swim” environment for mature great white sharks (i.e., too risky for juveniles and pups).
Will We Ever See Great White Sharks in Chile Again?
Great white sharks are the largest predatory warm-blooded fish on earth. They are decreasing rapidly in number due to overfishing and are considered to be vulnerable to extinction. Although they are highly migratory, great whites are seldom found off the coast of Chile. The evidence of paleo-nurseries is from an era when the climate and coastal waters were relatively warmer than observed today. This suggests a possible correlation between the two.
As Jürgen Kriwiet, Chair of Palaeobiology and Vertebrate Palaeontology at the University of Vienna, Austria, told Newsweek, “[if] we can reconstruct shifts due to climate change (as we propose for the past) we can better understand the impact of ocean warming on these important top predators in food-webs and thus also how food-webs might be altered in the future due to climate change.”
Dr. Mahesh Balwant Khot is working as a postdoctoral scientist at Biotechnology Centre of University of Concepcion at Concepcion campus of Chile. Dr. Mahesh is handling a FONDECYT, Goverment of Chile funded project, on biodiesel production from a newly isolated yeast obtained from Valdivian temperate forest ecosystem of southern Chile. He obtained his Ph.D. in microbiology from Shivaji University, Kolhapur and University of Pune in India.