El Niño Draws Exotic Marine Species to California Waters

Rising ocean temperatures are pushing tropical wildlife further north along the Pacific coast.

Updated on Oct. 20, 2026 in Environmental

A lone oceanic manta ray swims through the deep blue waters of the California coast, illuminated by sunlight filtering from above. — Rising ocean temperatures from El Niño are pushing tropical marine species like manta rays into northern California waters, disrupting local ecosystems. AI Illustration. Upload story photo >

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Do you think extreme marine temperatures are permanently altering the wildlife found in your local waters?

El Niño conditions and a marine heatwave are significantly raising water temperatures along the California coast. This shift is forcing exotic marine species to migrate into areas where they are rarely or never before recorded.

Why it matters

Weakened trade winds and reduced coastal upwelling prevent nutrient replenishment, disrupting food availability for native species and inviting tropical visitors. These environmental changes are also leading to starvation in local seabird populations.

Water temperatures at a depth of 50 feet near La Jolla reached 70 degrees Fahrenheit (21 degrees Celsius) as of October 7. This warming coincides with the sixth confirmed yellow-bellied sea snake sighting in California history.

The details

Recent sightings have included a rare longfinned bigeye caught at the Venice Fishing Pier and various tropical creatures such as whale sharks and oceanic manta rays. These shifts are driven by El Niño, which replaces cool, nutrient-dense water with warmer, nutrient-poor surface water.

July 2026: Seabird deaths were reported along the California coast.
September 2026: A yellow-bellied sea snake was spotted at Crystal Cove.
October 7, 2026: Water temperatures near La Jolla reached 70 degrees Fahrenheit.
Upcoming months: El Niño is expected to reach its peak strength.

The Big Picture

This event mirrors the ecological disruptions documented during the 2015-2016 El Niño event. These observations provide a critical baseline for understanding how sustained marine heatwaves alter the biodiversity of the Pacific coast.

The warming ocean temperatures threaten the health of local kelp forests by preventing the nitrogen and phosphorus replenishment necessary for growth. Residents may observe unusual wildlife behavior or rare species along coastal areas as temperatures continue to rise.

The takeaway

The presence of tropical species serves as a clear indicator of the significant stress currently placed on the California marine ecosystem. Residents should remain aware that these shifts are expected to intensify as the current El Niño reaches its peak.