(Stock.tv) – Lemon sharks “travel” to where they were born to spawn.
Research in Bimini, Bahamas, spanned nearly two decades, showing that citronella sharks born here return after 15 years to produce the next generation, the first confirmed behavior, in sharks.
The study began in 1995, where researchers captured, tagged and released more than 2,000 baby sharks over 19 years.
This study was published online in the journal Molecular Ecology on December 5, 2013, titled “Two Decades of Genetic Biography Showing Early Evidence of Repatriation (Natal Philophagus) and Enduring Fidelity to Sharks,” the study was a collaborative effort of scientists from The Field Museum, the Bimini Biological Field Station Foundation, University of Miami and Stony Brook (SBU).
Study results show that local and international efforts can make a big difference in the fight to restore shark populations in coastal areas around the world. Sharks have been overexploited to feed Asian restaurants and banquet halls. Shark fin is a key ingredient in a soup from these restaurants and is rated for significant cultural significance, but has no nutritional value.
“We used the DNA markers from sharks to build a large family tree,” explained Dr Kevin Feldheim, Kevin Feldheim is the laboratory director at the Field Museum and lead author of the study.
“We found that baby sharks captured since the mid-1990s left the safety of the islands when they were 5 or 8 years old. However, despite departing and visiting many other islands on their journey, these sharks still “remember” where they were born after decades of travel and are able to rediscover this island. When they are pregnant and ready to give birth, ”added Dr. Feldheim.
Many researchers have speculated that female sharks are likely to return to where they were born to give birth, but it is difficult to track sharks from birth to adulthood, which remains to be proven. Hundreds of student volunteers traveled to the Bahamas to help support an ongoing 19-year research effort, finally proving the speculation to be correct.
“The lagoons of Bimini are almost like a lake,” said the founder of the project, Dr. Samuel Gruber, president and director of the Bimini Biological Station Foundation. “I found out that we have the ability to capture almost every shark born in the lagoon every year, which gives us a special chance to see if the female sharks really came back here to give birth or not. However, it took us almost twenty years and many hours of field and lab work, but in the end we have answered this long-standing question and many more with this article.
Sharks live long lives and take years to mature, which is why they are so easily overfished. Evidence that sharks use similar areas between generations for reproduction underscores the importance of environmental conservation, local shark nurseries in the wild, and being able to rely on the design of coastal marine protected areas. , to protect future generations of sharks. The truth is that some sharks are closely related to certain regions, as opposed to those that roam the ocean. It also shows that individuals and groups from neighboring countries can act on their own to protect sharks.
Study co-author Dr Demian Chapman, assistant professor in the School of Marine and Atmospheric Sciences and deputy scientific director of SBU’s Institute of Marine Conservation Sciences, said he started 17 years ago as a volunteer researcher in Bimini on a capture mission. sharks to mark them.
“When we tagged the first whales in Bimini, Bill Clinton was then President of the United States,” Chapman said. “When the sharks start to mature and return to give birth, now Barack Obama is the president.” If you think about everything that has happened in the world during this time, this is the time needed for many mature sharks.
