Sharks VS Orcas, Dolphins, & More! | 2025 Sharkfest MEGA Episode | National Geographic

Key Concepts

Great white sharks, tiger sharks, megasharks, shark conservation, shark behavior, shark attacks, apex predators, bull sharks, hammerhead sharks, fin cam technology, shark tagging, acoustic monitoring, orca predation, echolocation, electroreception, shark personalities, boat-shark interactions, chumming, bait, marine ecosystems.

Great White Sharks in Hawaii

• Unusual Sighting: Great white sharks are rarely seen in Hawaii.
• Whale Carcass Attraction: A sperm whale carcass near Oahu attracted sharks, including a great white.
• Kimberly Jeffries & Mark Mohler: Wildlife photographer Kimberly Jeffries and boat captain Mark Mohler sought to photograph the sharks.
• Initial Observations: Tiger sharks and oceanic white tips were present.
• Discovery of a Great White: A large great white shark, estimated at 6 meters (20 feet), appeared.
• Opportunity of a Lifetime: Kim and her friends seized the opportunity to document the shark.
• Mark's Arrival: Mark joined the group later and also witnessed the great white.
• Identification Efforts: Kim hoped to identify the shark using photos and videos.

Kamakai: A Megashark in French Polynesia

• Tiger Sharks in the South Pacific: The South Pacific is known for large tiger sharks.
• Kamakai: Marine biologist Kori Burkhardt recorded a massive female tiger shark in 2018 and named her Kamakai.
• Size Estimation: Kamakai was estimated to be 16 feet long, significantly larger than typical tiger sharks.
• Unusual Girth: Kamakai's width was also remarkable, possibly indicating pregnancy.
• Search for Kamakai: Kori enlisted cameraman Andy Casagrande to find Kamakai again.
• Sharkapolis: French Polynesia's waters have become a "Sharkapolis" due to shark fishing bans.
• Dorsal Fin Identification: Kori and Andy planned to photograph dorsal fins for identification.
• Encounter with Another Large Female: They encountered another large female tiger shark, but it wasn't Kamakai.
• Significance: The encounter supported findings that larger sharks thrive in Polynesian waters.

Deep Blue: The Legendary Great White

• Identification of the Hawaiian Great White: Kim Jeffries contacted George Probst, who suggested the shark might be Deep Blue.
• Deep Blue's History: Deep Blue is a famous great white shark filmed off Guadalupe Island, Mexico, in 2013.
• Size Recalculation: Using Kim's photos, scientists estimated Deep Blue to be at least 20 feet long.
• Migration Patterns: Satellite tags revealed that white sharks in the Northeast Pacific migrate to a shared offshore foraging area between Hawaii and Baja.
• Deep-Sea Sightings: ROV and submersible missions have sighted white sharks at depths of 1000 feet around Hawaii.
• Distance Traveled: If Deep Blue swam from Guadalupe to Hawaii, she would have covered over 2,400 miles.

Haole Girl: A New Great White

• Second Sighting: Kim and Andrew returned to the whale carcass and encountered another large great white.
• Naming Haole Girl: Kim named the new shark "Haole Girl" as a tribute to Hawaiian culture.
• Boat Encounter: Haole Girl showed interest in their boat, "Rubber Ducky," and bit one of the tubes.
• Boat Damage: The bite caused a gash and air leak, leading to the boat sinking.
• Mark's Rescue: Mark arrived to help, and captured photos of Kim and Haole Girl.
• Multiple Sharks on One Whale: The presence of three large female white sharks on one whale was unusual.

Fin Cam Footage in French Polynesia

• Lagoon Full of Juveniles: The search for Kamakai led to a lagoon with many juvenile tiger sharks.
• Fin Cam Deployment: Andy and Kori deployed fin cams on two juvenile tiger sharks to monitor their behavior.
• Camera Retrieval: Both fin cams were retrieved, one inside the lagoon and one outside.
• Camera Shark Behavior: The footage showed the sharks interacting with other juveniles.
• Lagoon as a Sanctuary: The lagoon may serve as a safe haven for young tiger sharks.
• Pupping Ground Theory: The presence of young sharks suggests a nearby pupping ground.
• Tiger Paradise: French Polynesia's waters have become a "tiger paradise" due to protection measures.

Bull Shark vs. Great Hammerhead

• Viral Video: A video surfaced showing bull sharks attacking and killing a great hammerhead.
• Dr. Mike Heithaus' Investigation: Marine biologist Dr. Mike Heithaus assembled a team to investigate this unusual interaction.
• Captain Mike Myers' Account: Fishing charter captain Mike Myers witnessed the event.
• Hammerhead Size: The hammerhead was estimated to be 12-13 feet long.
• Bull Shark Tactics: The bull sharks repeatedly grabbed the hammerhead by the tail.
• Unprecedented Event: Such an attack between apex predators is rare.
• Team of Experts: Dr. Heithaus assembled a team to study bull sharks and great hammerheads separately.
• Erin Spencer's Hammerhead Research: Erin Spencer led the investigation of great hammerheads.
• Biologgers: They used biologgers (animal-mounted data collecting devices) to track hammerhead movement.
• 3D Tracking: The biologgers provided a three-dimensional path of hammerhead movement.
• Boca Grande Pass: The team focused on Boca Grande Pass, known for tarpon migrations and shark activity.
• Hammerhead Tagging: The team attempted to tag a great hammerhead with an accelerometer tag.
• COVID Exposure: Erin Spencer was exposed to COVID and couldn't participate in the tagging.
• Hammerhead Predation Attempt: While tagging, another hammerhead circled, potentially attempting predation.
• Tag Deployment: The team successfully deployed the tag on a 10-foot-plus great hammerhead.
• Hammerhead Data Analysis: Erin analyzed the data, revealing the shark's movements and energy expenditure.
• Hydrodynamic Cephalofoil: The hammerhead's cephalofoil (head extension) allows for rapid turns and precise movements.
• Hammerhead Agility: Hammerheads are more nimble and agile than bull sharks.
• Dr. Yannis Papastamatiou's Bull Shark Research: Dr. Yannis Papastamatiou led the investigation of bull sharks.
• Camera Tag on a Bull Shark: The team attempted to put a camera on a free-swimming bull shark.
• Shark Super Highway: The southeast coast of Florida is a "shark super highway."
• Silky Shark Interference: Silky sharks interfered with the tagging process.
• Successful Tagging: The team successfully tagged a large female bull shark.
• Cloacal Swabs: The team took cloacal swabs (fecal samples) to analyze bull shark diets.
• Tonic Immobility: Flipping the shark on its back induced tonic immobility, a relaxed state.
• Acoustic Tagging: The team implanted an acoustic transmitter to track the shark's movements.
• Fin Cam Retrieval: The fin cam was retrieved after two days.
• Bull Shark Social Behavior: The footage revealed a gang of bull sharks interacting.
• Shark Consumption: The cloacal swabs showed that bull sharks were eating other sharks.
• Bimini Expedition: The team traveled to Bimini to observe bull sharks and hammerheads up close.
• Candace Fields' Expertise: Local scientist Candace Fields led the Bimini expedition.
• Hammerhead Dominance: A 13-foot female hammerhead dominated the bull sharks.
• Bull Shark Retreat: The bull sharks retreated in the presence of the larger hammerhead.
• Hammerhead Maneuverability: The hammerheads demonstrated superior maneuverability.
• Compromised Hammerhead Theory: The team theorized that the hammerhead in the viral video was compromised (injured or sick).
• Tarpon Season: The attack occurred during tarpon season, suggesting a possible fishing-related injury.
• Bull Shark Opportunism: The bull sharks may have sensed the hammerhead's weakness and attacked.
• Hammerhead Victory: The team concluded that in a fair fight, the great hammerhead would likely win.

Orca Predation on Great White Sharks

• Orca Attacks in South Africa: Orca have been observed hunting and killing great white sharks in South Africa.
• Shark Disappearance: After the orca attacks, the great white sharks disappeared from the area.
• New Zealand Investigation: Kina Scollay and Dr. Ingrid Visser investigated whether orca might hunt great whites in New Zealand.
• Large Shark and Orca Populations: New Zealand has a large great white shark population and a local orca population.
• No Washed-Up Sharks: No great white sharks have washed up on New Zealand beaches.
• Orca Hunting Techniques: Orca in New Zealand typically target specific parts of their prey, such as the liver.
• Sevengill Sharks: New Zealand orca have acquired a taste for shark liver from sevengill sharks.
• South African Pattern: South African orca started hunting sevengills before moving on to great whites.
• Fiordland National Park: Kina and Ingrid dived in Fiordland National Park to look for signs of orca predation on sevengills.
• Lower Sevengill Numbers: They observed lower sevengill numbers than expected.
• Echolocation: Orca use echolocation to find prey, even when buried in the sand.
• Ray Hunting: Orca in New Zealand traditionally hunt rays and skates.
• Ray Hunting Challenges: Ray hunts can be difficult and risky for orca.
• Liver as a Prize: Liver is a valuable source of energy for predators.
• Great White Liver Value: A great white shark liver could be equivalent to many ray livers.
• Orca Hunting Culture: New Zealand orca have a strong culture of hunting sharks.
• Warming Oceans: Warming oceans could affect the availability of rays and skates, potentially leading orca to target great whites.
• Bite Marks on a Great White: The team observed a great white shark with unusual bite marks on its dorsal fin.
• Orca Teeth Marks: The bite marks resembled orca teeth marks.
• Sound Experiment: The team conducted an experiment using recorded whale sounds.
• Humpback Whale Song: The sharks responded to humpback whale song.
• Orca Sounds: The sharks moved away from the sound of New Zealand orca hunting.
• Ancient Battle: The struggle between orca and great white sharks may be an ancient and ongoing battle.

Shark vs. Dolphin

• False Killer Whales: False killer whales (actually dolphins) hunt sharks.
• Dolphin Intelligence: Dolphins are intelligent predators.
• Shark-Dolphin Conflict: Sharks and dolphins often come into conflict.
• Shark Bay, Australia: Shark Bay is a hotspot for shark-dolphin interactions.
• High Scarring Rate: 75% of dolphins in Shark Bay show scars from shark interactions.
• Fin Cam Mission: The team aimed to capture video evidence of shark-dolphin combat.
• Dolphin Social Behavior: Dolphins are social animals and tend to hang out in larger groups when vulnerable.
• Tiger Sharks as a Threat: Tiger sharks are a major threat to dolphins in Shark Bay.
• Tiger Shark Hunting Style: Tiger sharks are known for a casual kill.
• BRUV Deployment: The team used baited remote underwater videos (BRUVs) to find sharks.
• Remoras: Large remoras can indicate the presence of a large shark.
• Dolphin Rescue Stories: Stories abound of dolphins rescuing swimmers from sharks.
• Great White Attack on a Dolphin: Two Australian oystermen witnessed a great white shark attacking a dolphin.
• Dolphin Blubber: Dolphins have blubber, making them a nutritious meal for sharks.
• Dolphin Maneuverability: Dolphins are fast and can outmaneuver sharks in open water.
• Monkey Mia: The team visited Monkey Mia, where dolphins come close to shore.
• Piccolo: A dolphin named Piccolo had scars from shark encounters.
• Shallow Seagrass Beds: Dolphins often forage in shallow seagrass beds, where tiger sharks also hunt.
• Echolocation: Dolphins use echolocation to "see" in dark environments.
• Dolphin Blind Spot: Dolphins have a blind spot behind and below them.
• Breach Attacks: Great white sharks use breach attacks from below.
• Stealth Predators: White sharks are stealth predators.
• Pod Safety: The safety of the pod can stop an ambush.
• Mako Sharks: Mako sharks are among the fastest fish in the sea.
• Mako Attack on a Dolphin: A mako shark was filmed attacking a dolphin off Hawaii.
• Fin Cam Deployment: The team deployed a fin camera on a tiger shark.
• Bronze Whaler: They caught a bronze whaler instead of a tiger shark.
• Orca Predation on a Tiger Shark: A pod of orcas was filmed attacking a tiger shark off Costa Rica.
• Fin Cam Retrieval: The team retrieved the fin cam, but it didn't capture any dolphin encounters.
• Seaweed Distraction: Captain Ash witnessed dolphins using seaweed to distract a tiger shark from a juvenile dolphin.
• Night Vision Camera: The team deployed a night vision camera.
• Limited Night Vision Footage: The night vision camera captured limited footage.
• Ecosystem Balance: The balance between sharks and dolphins is important for a healthy ecosystem.
• Bait Ball Ceasefire: Sharks and dolphins sometimes work together to prey on bait balls.

Bahamas Shark Research

• Bimini as a Battleground: The waters off The Bahamas are a battleground between sharks and dolphins.
• Photographic Evidence: The team used photographic evidence to study shark attacks on dolphins.
• Atlantic Spotted Dolphin and Bottlenose Dolphin: The team focused on the Atlantic Spotted Dolphin and the sleek grey Bottlenose.
• Shark Bite Scars: Nearly one third of dolphins here show signs of shark attack.
• Crater Feeding: While foraging, some dolphins occasionally break away from the pod to crater feed.
• Vulnerable Dolphins: This is when the dolphins are most vulnerable.
• Shark Species: The team focused on the bigger bull sharks, tiger sharks, and maybe great hammerheads.
• Bite Characteristics: The team looked at bite characteristics to identify the shark species.
• Great Hammerhead Bite: The team sets out in search of the great hammerhead to see how it might be biting these undersea mammals.
• Bonito Bait: The team used whole bonito to get a bite impression.
• Tiger Shark and Bull Shark Interference: Tiger sharks and bull sharks are ambush predators, known to sneak up on their prey.
• Nurse Shark: Those nurse sharks are definitely coming to check us out.
• Hammerhead Approach: Finally, the great hammerhead approaches, and her size lives up to the name.
• Tearing Bite: The tearing bite of the hammerhead matches the ragged scars seen on the dolphins.
• Dolphin Defenses: Dolphins have an arsenal of defenses, including intelligence.
• Echolocation: Echolocation is really kind of a dolphin's superpower.
• Clearwater Marine Aquarium: The team visited the Clearwater Marine Aquarium in Florida.
• Cognitive Concept: This is a cognitive concept called the match to sample.
• Blacktip Shark: Blacktip sharks, every time I've been in the water with them, they always behave erratically.
• Tiger Beach: The team heads to Tiger Beach, in The Bahamas.
• Serrated Teeth: Tiger sharks also have teeth that are curved and have serrations, so they cut in both directions.
• Hydrophone: We're going to use this hydrophone, an underwater microphone, to hear the sounds through the headphones and hear their whistles, squeaks, squawks, chirps.
• Cloacal Swab: The team needs to take a cloacal swab, otherwise known as a fecal sample.
• Tonic Immobility: Flipping the shark on its back puts it into tonic immobility, a relaxed, trance-like state.
• Acoustic Tags: The acoustic tags can help the team see where and when bull sharks may overlap with great hammerhead habitat.
• Fin Cam Surfaces: Two days later, the bull shark's fin cam surfaces.
• Gang of Bull Sharks: It's a gang of bull sharks.
• Cloacal Swabs: The results from the cloacal swabs also arrived.
• Bimini: The Bahamian islands of Bimini are only 50 miles east of Florida.
• Decoy Dolphin: For the first time ever, a decoy dolphin as their secret weapon.
• Gelatin Block: This is basically a gelatin block that is the density of dolphin blubber and we've turned it into a giant underwater lollipop.
• Laser Device: A laser device can pinpoint the exact length of the shark.
• Gooey: This is Gooey, our dolphin model and Gooey was made out of non-toxic gelatin.
• Peduncle: The peduncle is a really strong muscle at the tail end of the dolphin, and it allows them to move their tail really fast, it allows them to maneuver, and get to great speeds.
• Bait: Definitely, adding the bait, that extra scent will really entice the sharks to bite Gooey.
• 3D-Scan: With the 3D-scan were we able to see how each tooth moved through and that these bull sharks are leaving clean bites even on big round dolphins and it really showed us that it's going to take a big adult bull shark to take down a dolphin.
• Evolution: Evolution tends to hone behaviors that make predators super-efficient, and prey good at getting away.
• Health of the Oceans: The fact that there are so many sharks and so many dolphins in the Bahamas might be a really good sign for the health of the oceans here.

Shark Attacks on Boats

• Increasing Boat Attacks: There's a rise in videos showing sharks biting boats.
• Sensory Stimulation: Boating activities involve sensory stimulation that attracts sharks.
• Florida as a Shark Hotspot: Florida has diverse habitats that attract various shark species.
• Underwater Comms: The team used underwater comms to communicate with the diver.
• Engine Revving: The team revved the boat engine to attract sharks.
• Shark Hearing: Sharks have amazing hearing and can detect vibrations.
• Chum Bags: Chum bags are used to attract fish, but can also attract sharks.
• Nictitating Membrane: Sharks have a nictitating membrane to protect their eyes.
• Blood Samples: The team took blood samples to analyze shark diets.
• Caudal Vein: The caudal vein is the largest in the tail of a shark.
• Gel Coat: It just took a big bite out of the side of the boat here. It just shows how strong the bite force of these lemon sharks are. It's actually ripped part of the gel coat off with a couple of chunks out of the boat and actually shredded the rubber of the rub rail.
• Electric Fields: Boat engines emit electric fields that attract sharks.
• Electroreception: Sharks have ampullae of Lorenzini that detect electrical signals.
• Circuit Boards: The team used circuit boards to test shark electroreception.
• Kayak Attacks: Sharks sometimes attack kayaks and canoes.
• Silhouette: The silhouette of a kayak may mimic prey.
• Paddle Dipping: The sound of a paddle dipping may attract sharks.
• Bait: The team added bait to the kayak to attract sharks.
• Personalities: Sharks have different personalities, with some being bolder than others.
• Tasmania Attack: A shark grabbed a boy off a boat in Tasmania.
• Life Jacket: Many claimed the boy's life jacket and heroic father saved his life.
• Stimuli: They were fishing. There was that stimuli.
• Blood Sample: The results from the blood sample from the lemon shark are in.
• Not a Major Negative Effect: Most likely what's going on is that these sharks are in the area and, hey, maybe get a little bit of free food here. Why not take a few tail beats and go over there and check it out? Of course, there's more work to do, but the initial indications are certainly that this is not having a major negative effect on the sharks.

Conclusion

The video explores the complex relationships between sharks, dolphins, and humans, highlighting the importance of understanding shark behavior and the factors that contribute to both natural interactions and potentially dangerous encounters. It emphasizes the need for conservation efforts to maintain healthy marine ecosystems and promote coexistence between these apex predators and humans.