Scientists found that many millions of sharks carry hooks attached to their bodies from commercial fishing lines

New research finds out that several million sharks carry hooks caught in their bodies by merchant fishing lines that can remain lodged for as long as SEVEN years.

38% of sharks had commercial fishing gear in the body.
38% of sharks had commercial fishing gear in the body.

According to brand-new research by the Institute of Marine Biology of the University of Hawaii at Manoa, hooks attached to sharks' skin or mouth can stay in the skin or mouth for numerous years and trigger severe health problems, consisting of internal bleeding and necrosis.

In 2011-2019, a team of researchers kept an eye on tiger sharks in the ocean around Tahiti and found that 38% of them had commercial fishing gear in the shark body.

Countless sharks around the world are quietly struggling with business hooks attached to their skin, unable to eliminate them by themselves.

Tiger sharks were tagged by researchers in Tahiti from 2011 to 2019.

There were 38% of sharks found to be caught on a hook at least one time.

The hooks can remain in their bodies and cause necrosis or internal bleeding for years.

"This is a problem that probably affects millions of individual sharks throughout the ocean," Carl Meyer, a fellow at the Hawaii Institute of Marine Biology, said in an interview with Newsweek.

"Sharks get caught in a wide variety of fisheries, from coastal recreational fisheries to commercial offshore longline fisheries.

The hooks can cause anything from small irritation to internal bleeding as a swallowed hook tears at the shark's internal organs.

If connected, sharks frequently bite the line or break, or are let go by fishers without them eliminating the hook.

To date, the most precise conclusions on the effect of commercial shark fishing indicate some 100 million sharks are killed each year in order to use their fins to make the popular Chinese shark-fin soup.

What the shark study discovered 

In this study, Meyer observed the 55 sharks at a site off the northwest coast of Tahiti between 2011 to 2019.

For some time, the retention of fishing equipment, that is, when marine animals escape the fishing equipment, retaining part of it their body, had been recognized as a possible problem, but certain key questions have been very difficult to answer, said Meyer.

“The main ones are: 1) How long do sharks keep hooks and fishing lines stuck? And 2) What is the impact of hooks and fishing line on shark health?

We realized that we could answer both questions using the photo identification data set of tiger sharks, in which each individual shark, identified from its unique characteristics, such as its scars and natural marks, was photographed on different occasions for several years.

The scientists identified two main types of hooks: those made of stainless steel and others made of material capable of corroding. 

All hooks made with materials of the latter type were detached before a period of two and a half years. 

On the other hand, stainless steel hooks can remain stuck in the shark's body for more than seven years.