Sharks also repatriated to breed

(lemon shark) - Lemon shark 'journey' to where they were born to breed.

The study, conducted in Bimini, the Bahamas, which lasted nearly two decades, showed that the female shark was born back here after 15 years to produce the next generation, for the first time asserting behavior. This is in the shark.

Research began in 1995, researchers arrested, tagged and then released more than 2,000 baby sharks for over 19 years.

This study was published online in Molecular Ecology on December 5, 2013, with the title of the article 'Two decades of genetic biography showing the first evidence of repatriation (natal philophatry) and Long-term loyalty to sharks' breeding grounds , the study is a collaborative effort by scientists from The Field Museum, Bimini Biological Field Station Foundation, University of Miami and the University of Miami. Stony Brook (SBU).

The research results show that local and international efforts can make a big difference in the struggle to restore the world's coastal shark populations. Sharks have been overfished to provide fins for Asian restaurants and banquet rooms. Shark fin is a major ingredient in a restaurant's soup and is considered to have significant cultural significance, but has no nutritional value.

'We have used DNA markers of shark individuals to build a large family tree,' explains Dr. Kevin Feldheim, Kevin Feldheim, a laboratory manager at The Field Museum and The main author of the study.

'We found that baby sharks that have been captured since the mid-1990s have left the safety of the islands when they were 5 or 8 years old. However, although leaving and visiting many other islands during their journey, these sharks still "remember" where they were born after tens of years of mobile life, and can find that island again. when they are pregnant and ready to give birth , "Dr. Feldheim added.

Many researchers have speculated that female sharks have the ability to return to where they were born to give birth, but it is difficult to track sharks since they were born until they mature, so it is This is not yet proven. Hundreds of student volunteers have come to the Bahamas to help with the 19-year-long research effort, which ultimately proves to be correct.

"The lagoons in Bimini are almost like a lake," said project founder Dr. Samuel Gruber, president and director of Bimini Biological Field Station Foundation. 'I have found that we have had the opportunity to capture almost all these sharks born in this year every year, and this gives us a special opportunity to see if female sharks have Really come back here to give birth or not. However, it took us nearly twenty years and many hours of fieldwork and laboratory work, but in the end we answered this long-standing question and many others with this article. '.

Sharks live long and take years to mature, which is one reason why they are so easily caught. Evidence that sharks use similar areas between generations to reproduce has emphasized the importance of environmental conservation, local shark nurseries and can rely on it. to design coastal marine protected areas, to protect future shark generations. The truth is that some sharks are closely associated with some areas, as opposed to those in the ocean. That also shows that individuals and neighboring country groups can act on their own to protect sharks.

Co-author of the study, Dr. Demian Chapman, assistant professor at the School of Maritime and Atmospheric Science and assistant director of science at the Institute of Marine Conservation Science at SBU, said he began 17 years. Previously as a volunteer researcher at Bimini with the task of catching sharks to tag them.

"When we tagged the first baby sharks in Bimini, Bill Clinton was then president of the United States , " Chapman said. "When sharks begin to mature and return to give birth, at this time, Barack Obama is President." If you think about all that has happened in the world during that period, it is also the amount of time. need for many mature sharks ".