It is the most extensive migration ever recorded for a silky shark (Carcharhinus falciformis). It covers more than 27,666 kilometers in 546 days. It is an adult female, nicknamed ‘Genie’. It is named in honor of the late shark ecologist Dr. Eugenie Clark. The shark that traveled 27,000 kilometers left a trail that was recorded by researchers.
The satellite transmitter was mounted on its fins near Wolf Island, north of the Galapagos Marine Reserve. It was made in July 2021. The trip is equivalent to crossing the United States from coast to coast approximately four times.
Indiscriminate fishing
The studio broke the previous movement record almost six times. It illustrates the extensive use of sharks in the open ocean, far beyond national jurisdictions. There is an urgent need to establish regulations to conserve its biodiversity.
Dr. Pelayo Salinas de León is the lead author of the study. He noted: “We want to understand the migratory routes of silky sharks. It is crucial to develop strategies to decrease the global population. Sharks have roamed the world’s oceans for hundreds of millions of years. The cartographic boundaries that humans have established on paper mean nothing to them. “Their long migrations through heavily fished international waters expose them to significant risks.”
Silky sharks are particularly vulnerable to overfishing. This is due to their slow growth, late maturity and high demand in the global shark fin trade. They are classified as Vulnerable on the IUCN Red List of Threatened Species. They represent one of the sharks most frequently caught in artisanal and industrial fishing. That is why they are a conservation priority.
International waters
The shark that traveled 27,000 kilometers moved mainly in international waters. That’s how it was 99% of the time Genie was tracked. It was moving west and south, far away from the Exclusive Economic Zone administered by Ecuador around the Galapagos Islands. This highlights the critical need for international cooperation in protecting these islands for traveling oceanic sharks. The study is published in the Journal of Fish Biology.