Warmer Sea Temperatures and Shifting White Shark Populations are Altering Patterns of Human-White Shark Encounters
Updated December 30, 2025
At the tail end of Sharktober, California has seen three *incidents” involving great white sharks (white sharks) and humans with one tragic fatality. On December 12, a surfer was bitten in the hand and his surfboard at Salmon Creek in Sonoma County. This location, next to a seal haul out, steelhead and coho salmon spawning location, attracts a lot of wildlife, including fish, seals, and white sharks. According to California Fish and Wildlife records, ten of the 16 shark incidents recorded in Sonoma County since 1950 occurred at this location. The size of the bite in the board suggests that this is a smaller white shark, possibly a sub-adult, around 8- 10 feet. On the morning of December 22, another surfer experienced a savage bump to his board at Dillon Beach to the south in Marin County. The surfer was unharmed, and the size of the compression suggests a sub adult shark investigating potential prey. Juvenile white sharks prey primarily on rays and fish, while sub-adult sharks are transitioning from fish to marine mammals. This was the third recorded incident at Dillon Beach, also known as Shark Pit, due to the high amount of shark sightings. It is also near the effluent to Tomales Bay, a productive area with seals and fish, and a site of white shark tagging by researchers.
*Scientists no longer call encounters with sharks as attacks. The Department of Fish and Wildlife (CADFW) defines A shark incident as any documented case where a shark approached and touched a person in the water, or touched a person’s surfboard, kayak, paddleboard, etc. This summary does not include shark sightings where no contact occurred, instances where sharks approached boats, or cases where hooked sharks caused injury or damage.
The third December incident involving a white shark, and the tenth in 2025 involved an ocean swimmer. At around noon on Dec. 21, 52 year old Erica Fox, an experienced ocean swimmer, disappeared off Lovers Point near Monterey while swimming with her swim group, the Kelp Krawlers. A witness reported to authorities seeing a shark breaching with a person in the sharkʻs mouth not long after noon. Ms Fox did not make it ashore to join her group and was reported missing. Her body was recovered at a beach north of Santa Cruz, over 25 miles north and identified by her wetsuit and a shark deterrent on her leg on December 27. This is the 3rd recorded shark encounter at Lovers Point, although several incidents including fatalities have occurred in nearby Pacific Grove and Monterey. The last fatality at Lovers Point was in 1952 when a shark killed a swimmer on December 07.
Around 10% of white shark incidents recorded since 1950 occurred in the month of December. This was the 17th fatality recorded in the State by CADFW since record keeping began.
Prior to 2025, the last fatality in California was on October 1, 2023. Bay Area sailor identified as Felix Louis N’jai was reported missing while swimming with two friends at Wildcat Beach, a remote area in the Pt. Reyes National Seashore. Witnesses reported seeing a shark nearby, with accounts of a pool of blood where the swimmer was last seen. Suspected as the victim of a great white shark, Mr. N’jai has not been recovered. It is highly likely Mr N’jai was victim to the first recorded fatality by a shark in Marin County. This beach along Drakes Bay is in an area known to have high frequency of white sharks, including white shark encounters with surfers at nearby Dillon Beach. This area of coastline falls within the region notoriously, and perhaps now inaccurately, called the Red Triangle.
Surfers, swimmers and ocean enthusiasts along California’s central coastline are well aware of the hazards in the ocean, including powerful surf, thick fog and the strong currents of the nearshore waters. In the fall months an often unseen hazard lurks in the salty waters: the great white shark (white shark). With a large population of the few areas of the world home to aggregations of white sharks (Carcharhodon carcharias), California ocean recreationists have one of the highest risk of encountering white sharks in the world. An early assessment in 2006 determined around thirty-eight percent of recorded great white shark attacks on humans in the United States were bounded in an area of central California what became popularly known as the Red Triangle. At the time, this was eleven percent of the worldwide total.
The 1996 study by McCosker and Lea reported that the vast majority of attacks in California occured north of Point Conception, California (34°30’ N latitude), with only a single attack off Washington State. In the first scientific evaluation of human- white shark encounters in California, McCosker and Lea determined that 80% of attacks occurred from Humboldt County south to Monterey County, and 62% of total attacks have taken place along an approximately 100 mile stretch of coast between Marin County and Monterey County and out to the Farallon Islands (30 miles offshore). This high percentage of shark encounters and fatalies earned the region the nickname “The Red Triangle.” Attacks south of Point Conception are fewer because of the rarity of nearshore pinniped colonies, the favored food of adult white sharks, and physiological temperature constraints on young white sharks. The abundance of attacks further north is related to the abundance of pinnipeds overlapping a high level of water use by humans in the region, and a rebuilding shark population.
Curtis et al. (2012) found that only three fatal incidents involving white sharks occurred in Southern California in their later assessment of human- white shark encounters in the California segment of the Northeast Pacific population (NEP) of white sharks. However, a more recent evaluation published by Feretti et. al, in the journal Frontiers in Ecology and Environment indicates that the counties included in the “Red Triangle” (Monterey, San Mateo, San Francisco, Marin and Sonoma) accounted for only 73 out of the 201 total incidents (36%) and 46 of the 122 injuries and fatalities (38%).
Since 1993, there have been ten fatalities in California attributed to white sharks. Eight of these occurred between Mendocino and Point Conception, with one at San Miguel Island, and one in Southern California, in San Diego County. However, in recent years there has been an increase in non fatal human-white shark encounters in the south, particularly San Diego County.
In 2012 Curtis, reported an increase in human shark encounters with white sharks from Point Conception south. Contrary to past reports of white shark incidents being concentrated along the central coast, incidents with white sharks occur statewide, with some of the highest numbers in Southern California according to Ugoretz (2021). This increase in human shark encounters is correlated with the increase in the white shark population since protection of the species was initiated in June 1994 by the California Department of Fish and Game (now Fish and Wildlife).
Contrary to earliar studies, where White Shark incidents were concentrated in an an area of northern California, incidents have occurred statewide, with some of the highest numbers in southern California. While total reported incidents are increasing, the annual number of incidents resulting in injuries or fatalities remains low.
The northeast Pacific population of sub-adult and adult individuals (white sharks) primarily consists of two discrete aggregations at Guadalupe Island, Baja CA Sur, Mexico (Domeier and Nasby-Lucas, 2008) and central California, USA. Adult white sharks from these two population segments seasonally migrate from North American waters to the north Pacific subtropical gyre called the White Shark Café’(Jorgensen et al., 2010. The first population assessment of white sharks in the California segment of the Northeast Pacific population was performed by Chapple et al in 2011. Using tag- recapture analysis and photographic IDs of dorsal fins between 2011 and 2018, the team estimated the adult shark population in the central California region at 219. The scientists estimated this number at approximately half of all mature and sub-adult ENP white sharks. In response to this study, Burgess et al, 2012 made an estimate of a range from 2,148 to 2,819 for the population of young, juveniles, subadults and adult white sharks in the NEP population.
Estimates of the Guadalupe Island population consisting of adult and subadult used tourist-based cage diving activities to monitor white sharks from 2014 to 2019 within the Guadalupe Island Biosphere Reserve. The data indicated a gradual increase in the overall abundance of white sharks with an age-structure shift, as young of the year and juvenile sharks were more prevalent during the latter part of the study period (2016–2019). The arrival of young of the year and juvenile white sharks coincided with regional changes in oceanographic conditions off California and Baja California.
Chapple, and later studies by Kanive in the central Pacific California aggregations focused on adult and subadult sharks because younger sharks are almost entirely absent in the region. White sharks are birthed in the warmer waters in the Southern California Bight and in Baja California. The bays and beaches serve as nursery sites and is where most juveniles and Young of Year and sub adults swim. Young white sharks consume fish and rays until they approach maturity. The range of the larger body- massed subadult and adult white sharks shifts northwards to points and islands where large aggregations of seals occur. The most recent estimate of the north central adult population (includes Ano Nuevo, the Farallon Islands to Point Reyes) at around 300 adult white (Kanive et al 2021). The authors also concluded the population of adult sharks in the central coast region is increasing slightly.
However, like the Guadalupe Population, an increase in young and juvenile white sharks has been observed north of Point Conception, a phenomenon previously undocumented. The westernmost promontory in California Point Conception creates a distinct sea temperature demarcation. This sea temperature break serves as a physiological barrier to young and sub-adult white sharks that have a preferential range of temperatures between 18 and 22 degrees C.
During the 2014–2016 North Pacific marine heatwave, unprecedented sightings of juvenile white sharks (Carcharodon carcharias) emerged in central California. Researchers onserved a dramatic increase in white sharks from 2014 to 2019 in Monterey Bay that was overwhelmingly comprised of juvenile sharks less than 2.5 m in total body length. These observations contradict the previosuly established life-history of white sharks, where juveniles remain in warmer waters in the southern California Current. The growing presence of juvenile sharks above 34° N suggests that climate change may be revising basic aspects of the established spatial population structure for this white shark population, and perhaps others.
Estimating population size and dynamics of sharks is challenging. Large distances are traveled by adults during migrations. When pregnant, females separate from the main population to gestate and pup in warm shallow regions like the Southern California Bight, Baiae de Vizcaino and in the Gulf of Califronia in Baja California. A separate 2021 study suggests the white shark population for the eastern north Pacific, especially those listed in the Gulf of California, might be underestimated. Researchers found that the mortality rates for these white sharks might be underestimated as well, as an illicit fishery for the species was uncovered in the Gulf of California, suggesting that fishers were killing many more white sharks than has been previously understood.
This spatial shift of range may create conflicts with commercial fisheries, the conservation of white sharks and endangered sea-otters, and may present public safety concerns. Warmer water temperature may impact the availability of fish and other prey that piniipeds, the primary diet of mature white sharks, may in turn reduce their populations, or cause those populations to move, potentially impacting the size and range of white sharks of the NE Pacific.
According to the California Department of Fish and Wildlife, there have been about 230 recorded and examined shark incidents along the west coast since 1950. *Incidents are defined as unprovoked bump or bite involving a human and a shark. Of the 230 incidents recoded over 75 years, only 16 were fatal as of this update. In this analysis, 200 of the 230 sharks were identified as white sharks. A study by Ugoretz et al (2022) indicates that slightly more than 30% of all shark incidents in California have occured in area called the Red Triangle. The authors note that Southern California, from Santa Barbara to San Diego County, also accounts for 30% of all incidents. The greatest number of shark incidents reported by CADFW was recorded in San Diego County (26), thus dispelling the old concept of The Red Triangle being ground zero for California white shark attacks.
Below is a breakdown of fatalities by white sharks in California. Swimming is the highest at risk activity. California sees an exponentially higher volume of drownings, with over 12,000 resident deaths between 1991-2020 (averaging around 400+ per year), according to the California Water Safety Coalition.
Table 1. Fatalities in California by Activity 1950-2025 (Source CA DFW)
| Swimmers | 7 |
| Surfing | 5 |
| Freediving | 3 |
| SCUBA/Hookah 1 | 1 |
| Kayaking | 1 |
| Total | 17 |
With a shift northward of white sharks, the Red Triangle may be more like a Red Trapezoid, with more serious white shark encounters shifting northwards with increasing sea surface temperatures and range shifts of sub adult sharks.
Avoiding shark attacks
Humans can reduce their risk of an attack or encounter by following prudent guidelines (link above). The chances of being bitten by a shark are quite low.
According to the California-focused study by Stanford scientists:
- Scuba divers are 6,897 times more likely to be hospitalized for diving-related decompression sickness than for white shark bites.
- Ocean-goers are 1,817 times more likely to drown than die from a shark attack.
- Scuba divers have a 1-in-136 million chance of being bitten.
- Surfers have a 1-in-17 million chance of being bitten.
The best way to avoid a shark encounter is to avoid locations and seasons where risk is highest, the study’s authors advise. For example, the riskiest time and place for California surfers is October and November in Mendocino County. That risk can be reduced 25-fold if you surf in March, and more than 1,600-fold if you surf in March between San Diego and Los Angeles.
Sources
McCosker J. E., Lea R. N. (1996). “White shark attacks in the eastern pacific ocean: an update and analysis,” in Great white sharks: The biology of carcharodon carcharias. Eds. Klimley A. P., Ainley D. G. (California, USA: Academic Press, San Diego), 419–434.
Ml Domeier, N. Nasby-Lucas Migration patterns of white sharks Carcharodon carcharias tagged at Guadalupe Island, Mexico, and identification of an eastern Pacific shared offshore foraging area Mar. Ecol. Prog. Ser., 370 (2008), pp. 221-237, 10.3354/meps07628
Taylor K. Chapple, S.J. Jorgensen, S.D. Anderson, P.E. Kanive, A.P. Klimley, L.W. Botsford, B.A. Block A first estimate of white shark, Carcharodon carcharias, abundance off Central California Biol. Lett., 7 (4) (2011), pp. 581-583, 10.1098/rsbl.2011.0124
Burgess GH, Bruce BD, Cailliet GM, Goldman KJ, Grubbs RD, Lowe CG, et al. (2014) A Re-Evaluation of the Size of the White Shark (Carcharodon carcharias) Population off California, USA. PLoS ONE 9(6): e98078. https://doi.org/10.1371/journal.pone.0098078
Curtis T. H., Bruce B. D., Cliff G., Dudley S. F. J., Klimley A. P., Kock A., et al. (2012). “Responding to the risk of white shark attack updated statistics, prevention, control methods, and recommendations,” in Global perspectives on the biology and life history of the white shark. Ed. Domeier M. L. (Florida, USA: CRC Press, Boca Raton), 477–509.
Paul E. Kanive, Jay J. Rotella, Taylor K. Chapple, Scot D. Anderson, Timothy D. White, Barbara A. Block, Salvador J. Jorgensen, Estimates of regional annual abundance and population growth rates of white sharks off central California, Biological Conservation, Volume 257, 2021, 109104,
ISSN 0006-3207, https://doi.org/10.1016/j.biocon.2021.109104.
(https://www.sciencedirect.com/science/article/pii/S0006320721001567)
Omar Santana-Morales | Rebeca Zertuche-Chanes | Edgar M. Hoyos-Padilla | Chugey Sepúlveda | Edgar E. Becerril-García | Juan P. Gallo-Reynoso | Isai Barba-Acuña | Adán Mejía-Trejo | Marc Aquino-Baleytó | Oscar Sosa-Nishizaki | James T. Ketchum | Rodrigo Beas-Luna An exploration of the population characteristics and behaviours of the white shark in Guadalupe Island, Mexico (2014–2019): Observational data from cage diving vessels Aquatic Conservation: Marine and Freshwater Ecosystems, 31(12), 3480– 3491 DOI: https://doi.org/10.1002/aqc.3734
Tanaka, K.R., Van Houtan, K.S., Mailander, E. et al. North Pacific warming shifts the juvenile range of a marine apex predator. Sci Rep 11, 3373 (2021). https://doi.org/10.1038/s41598-021-82424-9
Daniel J. Madigan, Natalie S. Arnoldi, Nigel E. Hussey, Aaron B. Carlisle. An illicit artisanal fishery for North Pacific white sharks indicates frequent occurrence and high mortality in the Gulf of California. Conservation Letters, 2021; DOI: 10.1111/conl.12796
Francesco Ferretti, Salvador Jorgensen, Taylor K Chapple, Giulio De Leo, Fiorenza Micheli Reconciling Predator Conservation With Public Safety- Frontiers in Ecology and the Environment 10 August 2015 https://doi.org/10.1890/150109
John Ugoretz, Elizabeth A. Hellme, ulia H. Coates Shark incidents in California 1950-2021; frequency and trends Front. Mar. Sci., 14 December 2022 Sec. Marine Megafauna, Volume 9 – 2022 | https://doi.org/10.3389/fmars.2022.10201
Summary of Documented California Shark Incidents California Department of Fish and Wildlife 1950 – 2025 Updated Dec 23, 2025