El Niño Has Brought Tropical Marine Species to California

Warmer waters have driven exotic marine life north into Southern California coastal regions.

Updated on Sept. 23, 2026 in Environmental

Sunlight filters through deep teal water into a California kelp forest as a distant marine creature swims by. — Rising ocean temperatures linked to El Niño have forced tropical marine species to migrate north into Southern California's coastal waters. AI Illustration. Upload story photo >

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Do you feel recent changes in your local climate are altering the wildlife in your area?

Tropical species including whale sharks and longfinned bigeye fish have appeared in Southern California waters due to rising temperatures. A rare olive ridley sea turtle also nested near Seal Beach as El Niño conditions persist.

Why it matters

Rising coastal temperatures have disrupted native marine food sources and altered local ecosystems. Experts anticipate further ecological shifts as the region faces a high probability of a very strong El Niño event.

Meteorologists forecast a greater than 90% chance of a very strong El Niño event influencing coastal waters. This phenomenon has already caused significant warming and migration of tropical species.

The players

Seal Beach

This coastal city serves as a key nesting site for endangered sea turtles and has fenced off areas to protect wildlife.

Huntington Beach

This coastal municipality is managing fenced-off nesting sites to protect local biodiversity from environmental stressors.

The details

Marine species have migrated north from Mexican waters because warmer ocean temperatures have reduced native food supplies. Reports include a whale shark near the Channel Islands, a yellow-bellied sea snake at Crystal Cove, and a longfinned bigeye fish at the Venice fishing pier.

Sept. 16: An endangered olive ridley sea turtle nested near Seal Beach.
Earlier this month: Hurricane Marie caused widespread coastal damage across the region.
Fall and winter: The region anticipates record surf, heavy rains, and cooling water.

Deeper Dive

This recent surge in tropical marine life follows a pattern set by the 2014-2016 El Niño event. Such conditions fundamentally alter local species distribution and coastal ecological balance.

Residents should be aware that native marine mammals may face increased health risks and stranding incidents during this period. Local beaches have implemented safety measures, such as fencing at nesting sites, to protect endangered species.

The takeaway

The migration of tropical species serves as a clear indicator of the profound impact that changing water temperatures have on local biodiversity. Residents can help by observing posted warnings near protected nesting sites along the coast.