Dead Great White Shark on California Beach Was Killed by Fishing Gear

An 8-foot-long great white shark has washed up on a beach in Torrey Pines, California, after dying from its injuries.

The shark, a juvenile, was killed after being injured by fishing activity, according to a Facebook post by the Torrey Pines State Natural Reserve. The shark washed up on the reserve's state beach, which is just north of San Diego.

"Yesterday an 8' long juvenile female Great White shark washed up dead near tower 2," the post said. "She had succumbed to injuries sustained from fishing activities. Great Whites are protected and must be safely released if accidentally caught. We took the opportunity to turn this unfortunate event into an educational opportunity for our visitors. Juvenile Great Whites have become a frequent visitor to the Torrey Pines coastal area."

Great white sharks are found all over the world, growing up to lengths of up to 20 feet, and weighing 5,000 pounds. "They have declined from historic numbers, particularly in the northwest Atlantic and South Pacific," Jane Williamson, a marine ecologist and fisheries biologist at Australia's Macquarie University, told Newsweek.

Great whites are classified as "vulnerable," according to the International Union for Conservation of Nature's Red List, having experienced a population decline of between 30 and 49 percent over the past few centuries. This is thought to be primarily due to human actions, with overfishing and plastic pollution killing thousands of sharks each year.

"The main threats to white sharks are human-induced, especially inshore commercial fisheries. These fisheries include longlines, hand-held rods, setlines, etc., that use hooks, which can cause issues later," Williamson said.

If a fishing hook is ingested by a shark, it may cause cachexia as the shark slowly starves to death, she said. The hook and line can also cause entanglement and deep wounds where the hook has torn the flesh. Fisheries also use gill nets and other types of fishing gear that can entangle the sharks.

"Ghost fishing gear is a major problem to all marine wildlife, not just elasmobranchs, and is a much bigger threat than actively fishing these creatures," Nicholas Ray, an aquatic ecologist at Nottingham Trent University, said. (Ghost fishing gear is abandoned, lost or discarded fishing gear.)

"As there are over 400 species of shark, they cover all parts of the ocean, from coastal regions, open ocean and various depths, which inevitably brings them in contact with the millions of tonnes of discarded ghost fishing gear and the colossal amount of plastic pollution in the oceans today," Ray said.

"Contrary to that, the bycatch of elasmobranch is most likely the biggest cause of shark and ray depletion, compared to fishing gear and plastic pollution impacts, but really none of this is helping our apex marine predators," he continued. "The over-exploitation [such as shark finning] and resultant losses through bycatch have greatly reduced shark and ray numbers over the decades."

Also, plastic pollution entangles the creatures and prevents them from swimming and feeding, and ingesting foreign bodies of plastic causes internal damage. All of this is "adding to the negative impacts on these ocean dwellers," Ray said.

While there are many organizations dedicated to studying and protecting shark species, they need to catch the sharks to sample them and attach tracking tags. This may also contribute to the loss of individual sharks, according to coastal ecologist Daryl McPhee from Bond University in Australia.

"Active fishing rather than marine debris is a larger source of mortality in most instances," McPhee said. "The shark in the [Facebook] photo has a tag attached for tracking. In order to install this tag, the animal would have been captured, presumably by scientists.

"The capture and subsequent tagging of sharks can cause mortality in some instances. It would be interesting to examine the movement data on the animal and the time at liberty, which would provide evidence for the actual cause of mortality," he said.