As the summer season approaches, California is bracing for an influx of juvenile great white sharks returning from warmer Mexican waters to the cooler coastal regions of the western United States. This year’s anticipated rise in shark populations marks one of the most significant migrations in a decade, attributed largely to the ongoing effects of the El Niño climate phenomenon.
An Unprecedented Season for Sharks
Recent observations from researchers at the California State University Long Beach (CSULB) Shark Lab have indicated an early arrival of juvenile great whites, with sightings beginning as early as February—an unprecedented occurrence. Dr. Chris Lowe, director of the Shark Lab, noted, “We’re already observing a high number of white sharks. Typically, we would expect to see baby white sharks starting in April, but this year has been different.”
The El Niño phenomenon, officially confirmed by the National Oceanic and Atmospheric Administration (NOAA) in early June, is expected to significantly influence marine ecosystems. This climatic condition can lead to warmer ocean temperatures, prompting various marine species, including sharks, to migrate northward as they seek more suitable habitats.
The Impact of El Niño on Marine Life
The current El Niño is predicted to be particularly potent, with implications extending beyond California’s shores. Ken Graham, director of NOAA’s National Weather Service, emphasised the variability of each El Niño, stating, “Every El Niño is not the same; each has its unique imprint on our weather.”
Historically, similar conditions have led to notable increases in shark populations along the Californian coast. In 2015, another El Niño year, researchers documented twice the usual number of white sharks, coinciding with a marine heatwave known as the “Blob.” Lowe recalled, “When we have these El Niño conditions, it gets too warm, and the white sharks don’t like it. It pushes them into California.”
Juvenile Sharks and Their Behaviour
Juvenile great white sharks, measuring between 6 and 9 feet, typically feed in shallower waters where prey such as stingrays, fish, and squid are abundant. The migration of these sharks to California’s waters is expected to attract not only great whites but also other shark species like smooth hammerheads, bull sharks, and possibly tiger sharks, as they follow the changing food supply.
In 2015, a notable increase in smooth hammerhead sharks was observed as they pursued schools of mahi-mahi, illustrating how shifts in marine biodiversity can occur during these climatic events. “I expect any day we’re going to start seeing hammerheads,” Lowe remarked, indicating the potential for a diverse array of shark species this summer.
Measures to Ensure Safety
In light of the anticipated increase in shark activity, local authorities have proactively implemented measures to safeguard both beachgoers and the sharks themselves. The California Department of Fish and Wildlife recently enacted emergency regulations to limit specific fishing gear usage at beaches and piers, a move designed to reduce accidental hooking of white sharks, which are fully protected under California law.
John Ugoretz, a fisheries and ecosystems program manager at the department, highlighted the pressing need for these regulations, especially given the rising interactions between humans and sharks in Southern California. “What we’ve seen already this year is a significant increase in people interacting with those white sharks,” he stated.
Despite these concerns, both Lowe and Ugoretz emphasised that shark encounters remain exceedingly rare. Since 1950, California has recorded fewer than 250 shark incidents, with only 17 resulting in fatalities—over 85% of these incidents involved white sharks. Lowe noted, “What we’re seeing in California is actually the opposite,” referring to the correlation between increased shark populations and a decrease in bite incidents.
Understanding Shark Behaviour
Beachgoers can take comfort in knowing that interactions with great whites are not indicative of predatory behaviour. “These sharks are around so many people, and they recognise that we’re not prey,” Ugoretz stated. He likened the experience of encountering a shark to spotting a bear in the wilderness—an exceptional event, albeit one that requires caution.
Lowe, reflecting on advances in research and understanding, expressed confidence in the safety of swimming alongside these apex predators. “How do we explain the fact that people are around white sharks every day, some 9-, 10-, 12-, 14-feet long, and are not being bitten? They’ve learned that we’re not food,” he asserted.
Why it Matters
The anticipated rise in juvenile great white sharks along California’s coast this summer is not only a reflection of shifting marine ecosystems due to climatic changes but also an opportunity for enhanced public awareness regarding shark behaviour and conservation. As these majestic creatures reclaim their territory, understanding their movements and behaviours will be crucial in fostering a safe coexistence between humans and marine wildlife, ultimately promoting the health of ocean ecosystems.
