Author Archives: George Probst

About George Probst

George T Probst is an award-winning American photographer best known for his underwater great white shark photography. In addition to his work underwater, Probst travels to schools, businesses, and communities for public speaking events to discuss the importance of sharks and ocean conservation. Probst was born in Fort Monmouth, New Jersey but spent his childhood moving around the world a bit. His family moved to Curundú, Panama when he was an infant, followed by Burke, Virginia, and then Osthofen, West Germany. At age 10, he moved back to Burke, Virginia where his parents continue to call home. Probst attended Virginia Tech and earned a track & field scholarship. He earned his B.S in Industrial and Systems Engineering and his M.S. in Human Factors Engineering. While in graduate school, George was a member of the United States Track & Field team at the World University Games in Palma de Mallorca, Spain. Probst began diving and photographing underwater wildlife in 2006 with a strong focus on the great white shark population of Isla de Guadalupe, Mexico. He has been a long-time contributor to the Marine Conservation Science Institute's Guadalupe White Shark Photo Identification research project, which documents unique individual white sharks at Guadalupe. Probst uses public speaking to raise awareness of the importance of sharks and other marine wildlife conservation through his photography and experiences in a way that is both educational and entertaining. Probst's photography has been featured by National Geographic, MTV, USA Today, Forbes, Discovery Channel, The National Wildlife Federation, and Yahoo! as well as other local, national, and international media outlets. The white sharks that appear on this site were photographed at Isla de Guadalupe, Mexico. The volcanic island, located 240km off the Baja coast, is a biosphere reserve where white sharks aggregate in the fall months. The sharks are drawn to the island by abundance of natural prey items including yellowfin tuna and northern elephant seals.

What happened to the legendary great white shark, Cal Ripfin / Shredder?

Now, that August has arrived it’s about that time of year when great white sharks (Carcharodon carcharias) begin to arrive at Mexico’s Isla de Guadalupe Biosphere Reserve. The island is regarded as one of the best places on Earth to view white sharks in their natural habitat. However, it’s one shark in particular that many are holding out hopes to see return.

Cal Ripfin (aka Shredder) was one of the most well-known great white sharks at Guadalupe prior to his disappearance following the 2011 season.

From 2001 to 2011, Cal Ripfin (aka Shredder) was one of the most well-known great white sharks to visit Mexico’s Isla de Guadalupe. Easily recognized by an injury to his dorsal fin that occurred sometime between the 2004 and 2005 season, Cal was a “fan favorite” of divers and photographers due to his inquisitive and curious nature. He would often swim right up the cameras as if he was posing for a photo opportunity.

White sharks gather at Guadalupe in the later months of the year, with the prime season considered to be between August and November. Cal consistently visited Guadalupe every season for 10 years straight, and his arrival was generally quite predictable. In 2009, he was absent early on in the season, which caused a bit of concern among researchers and divers, but he eventually showed up about midway through the season. However, after failing to be seen during the 2012 season, concerns once again rose for the well-being of Guadalupe’s favorite shark. When 2013 and 2014 passed by without any sighting of Cal Ripfin, hopes of his return were dampened even further.

Cal Ripfin (aka Shredder) wasn’t shy about swimming right up to the camera, which often created great opportunities for close-up shots.

While migratory tracking data is limited among Guadalupe white sharks, the available data indicates that SPOT tagged males follow a somewhat predictable pattern each year. The data shows males traveling to Guadalupe in the latter half of a year, and spending the rest of their time in the Shared Offshore Foraging Area (SOFA) (aka “the White Shark Cafe”), a remote area in the mid-Pacific. If the tracking data available is representative of the migratory behavior of all male Guadalupe white sharks, it does not bode well for Cal Ripfin, given his 3-year absence.

The question of why this male great white shark suddenly stopped returning to Guadalupe is one that will likely go unanswered, unfortunately.

So, what could have happened to him? Did he change his migratory routine? Did he die of natural causes, fall prey to another predator, or end up in a fishing net? At this point, it seems likely that his fate will always remain a mystery.

Somehow, I still have a tiny glimmer of hope that he’s still out there, but with each year that glimmer gets a little more faint.

Woman celebrates 100th birthday with great white shark dive

As part of Georgina Harwood’s 100th birthday celebration, she went on a great white shark dive off Gansbai, South Africa, yesterday. In addition to the shark dive, Harwood also celebrated turning 100 with a skydive two days earlier. Harwood, a great-grandmother, began skydiving when she was 92, but this was her first shark dive.

Her recent skydive was done, in part, to help raise money to buy life-jackets for volunteers at South Africa’s National Sea Rescue Institute, according to a HuffPost UK article.

If you’d like to donate to Harwood’s life-jacket fundraiser, you can do so here.

Great white shark caught from Florida beach

The catch and release of a young great white shark (Carcharodon carcharias) off of a Florida beach near Panama City has been making headlines for the past few days. According to a photo on Dark Side Sharker’s Facebook page, fisherman Derrick Keeny landed the shark on March 1, 2015. The male white shark measured 9’8″ and is believed to be the first of its species to be landed from a beach in the Gulf of Mexico. The fisherman tagged the shark as part of the NOAA/NMFS Cooperative Tagging Plan and released it back into the ocean.

While the fishermen involved in the catch seemed to be well-intentioned with the tagging and release of the shark. Some shark researchers and conservationists called into question the legality of bringing the shark up onto the beach and posing for pictures, which is in violation of Florida’s protected species regulations, which specifically prohibit delaying the release of the shark for measurements and photos. It has yet to be reported whether the fishermen involved will be subjected to any legal repercussions.

More images of the event are available of the Dark Side Sharkers Facebook page.

VIDEO: The Australian Museum receives rare goblin shark specimen

The Australian Museum recently received a new intact goblin shark (Mitsukurina owstoni) specimen. The specimen is that of a young male and measures 1.26m in length. The shark was caught off Eden, New South Wales in water that was “several hundred meters deep.” This marks the fourth goblin shark in the museum’s Ichthyology Collection.

The goblin shark is a deep-water species that is rarely encountered by humans. It is known for its rather unconventional appearance, which includes pink skin, a flattened snout, and a jaw that can extend forward to capture prey. Adult goblin sharks are thought to typically reach lengths between 3-4m. Though, a specimen caught Gulf of Mexico in 2000 was estimated to be between 5.4 and 6.2m.

For more information about the recently added goblin shark, check out The Australian Museum’s website.

Study indicates great white sharks grow and mature slowly

A recent study indicates great white sharks growth rates are much slower than previously thought.

Great white sharks (Carcharodon carcharias) grow and reach sexual maturity at much slower rates than previously believed, according to a press release from NOAA Fisheries. A study completed in 2014 and published online last month in the journal of Marine & Freshwater Research used carbon-14 dating and vertebral band pair counts of 81 white shark specimens, collected in the western North Atlantic Ocean, to develop a growth curve for the species. According to the results, female white sharks reach sexual maturity at approximately 33 years of age, while males reach maturity at approximately 26 years. Additionally, the results of the study indicate that the life-span of white sharks could exceed 70 years, which places them among one of the longest living species of fish.

The latest findings on the growth rates and life-span of white sharks provides important information for conservation efforts of the species. Low reproduction rates coupled with slow growth and maturation rates could potentially put the species at greater risk for population decline, since losses in populations are not quickly replaced. Great white sharks are a protected species in U.S. waters and legally must be released live, if captured. However, individual white sharks are sometimes killed as a result of incidental by-catch from commercial fisheries, so it is important that these types of incidents be managed to protect the welfare of white shark populations, as a whole.

For more information, check out NOAA Northeast Fisheries Science Center press release,

“White Sharks Grow More Slowly and Mature Much Later Than Previously Thought,”

and the Marine and Freshwater Research journal article,

“Age and growth of the white shark, Carcharodon carcharias, in the western North Atlantic Ocean.”

360-degree video offers viewers a virtual great white shark dive

Samsung is promoting it’s head-mounted Gear VR display with some 360-degree footage of great white shark diving off Port Lincoln, Australia. Head-mounted displays like the Gear VR and Occulus Rift offer viewers an immersive experience that can simulate a completely different environment.

I shot some similar white shark footage using the Kolor Abyss 360 rig at Isla de Guadalupe, Mexico, last September. This footage should be compatible with both the Samsung Gear VR and Occulus. If you don’t have a head-mounted display, you can still take advantage of the 360-degree effect, using your mouse to click and drag to change the angle.

Check out the 360-degree great white shark video

Stealthy seals sneak past white sharks using subsurface structures

The following was shared with us by shark researcher Michelle Jewell…

Stealthy seals use subsurface structures to sneak by white sharks

Written by Michelle Jewell (@ExpatScientist)

Predators are highly influential in ecosystems because of the many top-down effects they can have. The most obvious and direct way predators influence an ecosystem is by eating and reducing the number of prey animals in the system, but another equally important way is the indirect influence they have on the behaviour of prey animals.

If you have avoided parking on a risky-looking street, taken a different route between classes to avoid a bully, or abandoned a forest hike because of snapping twigs in the distance, you have been indirectly affected by perceived ‘predators’. In the wild, prey animals will also change their behaviour when they perceive that predators are around, and these altered behaviours often influence other species, ultimately shaping the ecosystem.

My research has focused on these same principles of predator/prey interactions in the ocean, and a great place to study oceanic predators and their prey are Cape fur seal colonies in South Africa. Every summer (November), Cape fur seals give birth to thousands of pups, and by winter (April – September) these ‘young-of-the-year’ seals begin to venture off their islands to swim offshore to the fishing grounds with the adults. These young-of-the-years are typically slow, plump from months of a mostly fat milk diet, and – most importantly – naïve. White sharks take advantage of this naivety and aggregate around seal colonies every winter. Young-of-the-year pups are forced to learn how to avoid sharks quickly or suffer some rather permanent consequences. This means that during a full year, every seal colony goes through a period of high white shark presence (winter) and very low to no white shark presence (summer). Therefore, we are able to study how seals act ‘normally’ during the summer when there are no/very few sharks and how they change their behaviour in the winter to avoid white sharks.

Also, there are many different kinds of seal colony islands along the coast, which lets us ask more questions about how seals use their environment to avoid sharks. I conducted my study at the Dyer Island/Geyser Rock system, which is home to ‘Shark Alley’ as well as many shallow reefs, kelp forests, and shipwrecks. About 100km to the east is another seal colony called Seal Island, which is a world-famous spot to see white sharks predate on seals, but this island system lacks the abundant nearby structures/reefs/kelp forests that are present at Geyser Rock. By looking at these two different kinds of islands, we can also examine how structures – or ‘refugia’ – may alter how seals avoid white sharks at Geyser Rock from how seals avoid white sharks at Seal Island.


Research Conducted by Marine Dynamics a Shark Cage Diving Operator in Gansbaai South Africa

Do all of these structures and anti-predatory tactics of Cape fur seals change white shark movements around Geyser Rock? Most definitely! Check out that study and infographic!

For more information, check out the detailed scientific publication in Behavioral Ecology & Sociobiology.

Video: Orcas hunt and kill tiger shark off Cocos Island

Vimeo user Edwar Herreño recently added a video documenting six killer whales (Orcinus orca) hunting a tiger shark (Galeocerdo cuvier) off Cocos Island. The orcas appear to use a team effort to huntand appear and then drown the shark in the video. The video description says that the orcas fed on the shark after killing it.

Discovery’s ‘Shark of Darkness: Wrath of Submarine’ draws criticism for being just awful

Much like last year’s mockumentary “Megalodon: The Monster Shark Lives”, Discovery Channel’s first episode of this year’s Shark Week has come under fire for it’s fictional account of “Submarine,” a giant man-eating great white shark with roots in a South African urban legend. “Shark of Darkness: Wrath of Submarine” plays out like a documentary, though it’s actually just an account of fictional events, plagued with less-than-convincing acting and special effects, in the eyes of many viewers.

Twitter was lit up with disgruntled viewers on Sunday night when the episode premiered, and numerous online media outlets have since voiced their distaste in Discovery’s decision to peddle out another faux “documentary.”

In Discovery’s defense, the show did contain the following vague disclaimer.

Events have been dramatized, but many believe Submarine exists to this day.

While most viewers realized from the get-go that this is a piece of fiction, others bought into it as a real-life account of a ‘monster shark’ with an appetite for humans. “Submarine” was noted to have an “insatiable taste for human blood,” and had adapted methods to attack humans more efficiently.

Is this really the kind of message Discovery Channel should be sending its viewers about sharks?


You can check some other opinions about Shark of Darkness by following the links below.

Atlantic White Shark Conservancy’s “We Need to Talk about Shark Week.”

Vox’s “Shark Week is once again making things up”

Gawker’s “Shark Week Returns With Its Lies”

PBS digital short: “What if There Were No Sharks?”

The latest episode of the PBS digital short series “It’s Okay To Be Smart” focuses on the important that sharks play in the environment and ponders the question of what would happen if there were no more sharks. During the video a counter representing an estimated number of sharks killed runs to give the viewer an idea of the rate at which sharks are being killed off. For a relatively quick watch, the video does a decent job at summarizing the value that sharks have in the world.