A Super El Niño will significantly affect global marine life

The world is in the midst of a strengthening Super El Niño that will likely set the record for the strongest ever observed.

We've already seen how this pattern will affect global weather patterns, including this autumn's conditions across Canada.

Marine life is already on the front lines of climate change's impacts. El Niño's powerful temperature rise will make things worse from the seafloor to your pocketbook.

DON'T MISS: Super El Niños can accelerate global sea level rise: study

El Niño disrupts critical ocean currents

The warmer-than-normal waters of an El Niño occur as trade winds change over the equatorial Pacific.

Trade winds in the region typically blow from east to west, pushing warm surface water toward Oceania. This flow allows for the upwelling of cold, nutrient-rich waters off the west coast of South America, helping to feed critters large and small alike.

El Niño results from these trade winds slowing down or reversing direction, which significantly slows the process of upwelling and robs the region of nutrients needed to sustain thriving marine life.

The amount of phytoplankton in the equatorial Pacific dropped precipitously between 2025 and the onset of El Niño in the summer of 2026, noted by satellites as a major reduction in chlorophyll throughout the region. Phytoplankton is a key food upon which the marine food web is built.

Warmer waters influence movement, abundance of fish

Aside from the weather, the availability and price of certain seafood may rank among the most noticeable effects of El Niño here on land. The anomalously warm waters can have a tremendous impact on the range, availability, and sheer number of certain fish species.

Tropical species tend to migrate north during El Niño. NOAA Fisheries noted one report of mahi mahi being caught near San Francisco, a city which is very much not in the tropics. The warming also influences cold-water species to move away from their typical ranges.

Pacific salmon are less bountiful during these warmer spells. Peru supplies a large percentage of the world's anchovies, which are directly affected by El Niños unfolding off the country's coastline.

Warmer ocean waters can also support harmful algae blooms, which can prove toxic to many forms of life throughout the affected regions.

Coral bleaching accelerates during El Niño

The world's coral reefs also feel the warmer temperatures. These formations are the bedrock of many tropical ecosystems.

Coral has very low tolerance for extreme temperatures in either direction. Waters running just a few degrees warmer than normal can cause coral to expel the algae it relies on for nutrition and protection, turning it a pale white colour in a phenomenon known as coral bleaching.

Bleaching events are dangerous for coral because it leaves them exposed and vulnerable to diseases. Much of the world's coral has experienced bleaching in recent years, and the conditions of a super El Niño will accelerate that trend in areas affected by the warmer waters.

Header image courtesy of Unsplash.