July 01, 2014

Study: Sand Sharks, Salinity, and the Arctic

Sci-News "The study, published in the journal Geology, indicates that these Eocene sharks were thriving in the brackish water of the western Arctic Ocean."

'In contrast, modern sand tiger sharks living today in the Atlantic Ocean are very intolerant of low salinity, requiring three times the saltiness of the Eocene sharks in order to survive.

'“This study shows the Arctic Ocean was very brackish and had reduced salinity back then. The ancient sand tiger sharks that lived in the Arctic during the Eocene were very different than sand tiger sharks living in the Atlantic Ocean today,” said lead author Dr Sora Kim of the University of Chicago.

'The new findings on Arctic Ocean salinity conditions in the Eocene were calculated in part by comparing ratios of oxygen isotopes locked in ancient shark teeth found in sediments on Banks Island in the Arctic Circle and incorporating the data into a salinity model.'

No comments: