Killer whales in Mexico’s Gulf of California have been recorded flipping juvenile great white sharks upside down and tearing out their livers, a behavior captured on Aug. 15, 2020, and documented in a peer-reviewed study published in Frontiers in Marine Science. The orcas induced a state called tonic immobility by inverting the sharks, then fed on liver tissue at the surface. The findings represent some of the clearest evidence yet that this specialized predation tactic is not limited to South African waters but is practiced by distinct orca populations thousands of miles apart.
Why liver-targeting attacks on white sharks demand attention now
The Gulf of California sits at a biological crossroads. It serves as a nursery habitat for juvenile white sharks and a feeding ground for regionally resident killer whales. When orcas target juveniles in a nursery zone, the consequences extend beyond individual kills. Juvenile white sharks that survive to adulthood help regulate prey populations across the eastern Pacific. Losing them at this life stage could thin future breeding cohorts in ways that are difficult to reverse and may alter food-web dynamics in ways that managers are not yet prepared to address.
Researchers Ayres, Gallagher, and Higuera-Rivas previously established that the same regional killer whales prey on large elasmobranchs in the Gulf of California, meaning the white shark attacks are part of a broader dietary pattern rather than isolated opportunism. That distinction matters because it suggests the behavior is learned and repeatable, not accidental. Once a pod masters how to immobilize and efficiently dismember large sharks, the technique can be passed along socially and deployed whenever similar prey are available.
A reasonable question follows: if seasonal prey depletion in the Gulf of California continues, will these orca pods expand liver-targeting attacks to include sub-adult white sharks? Increased carcass reports and drone-survey encounter rates over the next two years would be the clearest signals. No long-term tagging data currently exists to confirm or rule out that trajectory, but the documented pattern of repeated attacks on the same prey class points toward escalation rather than retreat. As juveniles grow into larger size classes, they may remain within the same coastal corridors, potentially keeping them within reach of the same experienced orca groups.
Tonic immobility and surface feeding in the Gulf of California
The 2025 Frontiers in Marine Science study provides the strongest primary evidence for how these attacks unfold. In detailed field observations, killer whales assaulted juvenile white sharks by turning them upside down, a maneuver consistent with inducing tonic immobility. Tonic immobility is a natural reflex in many shark species: when inverted, the animal enters a temporary paralysis, rendering it unable to resist. The orcas exploited this reflex to immobilize their prey before extracting the liver, a large organ rich in energy-dense oils called squalene.
After incapacitating the sharks, the orcas fed on liver tissue at the surface, leaving much of the carcass behind. This selective feeding pattern mirrors what has been observed off South Africa, where Towner and colleagues provided the first direct observation of killer whales preying on white sharks and documented a pronounced flight response among surviving sharks. In those South African events, white sharks abandoned entire coastal zones for weeks or months after orca attacks, effectively ceding territory to their predators and disrupting established patterns of coastal shark tourism and research.
Separate South African research published in the African Journal of Marine Science recorded an orca attack on a juvenile white shark that ended with liver consumption and rapid incapacitation, reinforcing the biological consistency of the technique across ocean basins. The liver of a white shark can account for a substantial fraction of the animal’s body weight, making it a high-calorie target that rewards the effort of subduing a large, powerful predator. From an energetic standpoint, repeatedly targeting livers may be more efficient than consuming entire carcasses, especially for socially coordinated hunters capable of disabling prey with precision.
Gaps in tracking data and what to watch next
For all the clarity the new study provides about attack mechanics, several questions remain open. No official records or statements from Mexican fisheries or marine-mammal authorities have addressed changes in white shark sightings or strandings linked to these orca attacks. Without that institutional data, researchers cannot yet calculate how many juvenile white sharks are lost to orca predation each season in the Gulf of California, or whether the rate is accelerating. The few confirmed carcasses may represent only a fraction of total mortality, given how quickly remains can sink, drift, or be scavenged.
Long-term tracking data from tagged sharks or orcas that would confirm repeated interactions between the same individuals is also absent. The existing evidence comes from short-term sighting reports and observational records, not from satellite tags or acoustic arrays that could reveal whether specific orca pods return to the same nursery areas year after year. Primary data on the exact duration and frequency of liver consumption per event is limited to observational notes in the 2025 paper, with no accompanying video timestamps or tissue-sample analysis publicly available. That leaves open basic questions about how many sharks are attacked in a single foraging bout and whether orcas shift to other prey when sharks are scarce.
The flight response documented in South Africa raises a parallel concern for Mexican waters. If juvenile white sharks begin abandoning the Gulf of California’s nursery habitat in response to orca presence, the population effects could compound. Young sharks displaced from productive feeding grounds face slower growth rates and higher mortality from other causes, a cascading problem that would be difficult to detect without systematic monitoring already in place. Any such displacement could also push juveniles into areas with heavier fishing pressure, increasing the risk of bycatch at the very stage when survival is most critical for population recovery.
Scientists watching the Gulf of California say several indicators deserve closer attention over the next few years. One is the spatial overlap between known orca travel corridors and historically important shark nursery zones. Another is the timing of attacks relative to seasonal pulses of other prey such as rays and smaller sharks, which may influence when orcas turn to white sharks as a high-value option. A third is whether carcasses show consistent signs of liver removal, such as cleanly opened body cavities with other tissues largely intact, a pattern already noted in the August 2020 event.
Answering these questions will require more than opportunistic photographs or chance encounters. Researchers are calling for coordinated surveys that combine boat-based observations, drone footage, and environmental DNA sampling to detect when sharks and orcas occupy the same waters. Carefully designed tagging programs for both predators and prey could reveal whether the same individuals are involved in repeated interactions and whether white sharks alter their movements after surviving an encounter. For now, the Gulf of California case underscores how quickly a single documented behavior-liver-targeting attacks on juvenile white sharks-can reshape scientific understanding of predator–prey dynamics in a region already under pressure from climate change and fishing.
More from Morning Overview
*This article was researched with the help of AI, with human editors creating the final content.
