Scientists have gotten a closer look at the impact of El Niño on the ocean. They've seen how this weather system affects phytoplankton, which can have a major impact on the oceanic food chain.
El Niño is a weather system that occurs every few years. During the times when it's active, huge masses of warm water travel east across the Pacific Ocean toward South America. This warm water can change storm systems in the atmosphere, and can cause ripples through the food chain in the ocean.
But why is this the case? El Niño's masses of warm water actually stops the normal currents of cold, deep water that usually rise to the surface off of the coast of Chile and Peru. With upwelling, these cold waters normally bring up the nutrients that feed the tiny organisms, which form the base of the food chain.
"An El Niño basically stops the normal upwelling," said Stephanie Uz, ocean scientist at the Goddard Space Flight Center. "There's a lot of starvation that happens to the marine food web."
In this latest study, the researchers used NASA satellite data in order to get a closer look at where phytoplankton, which are the basis of the food web, appear during different weather conditions. The satellites collected the color of the ocean and from examining these shades, the researchers could tell the amount of phytoplankton present in an area.
In December 2015 during the peak of the present El Niño event, scientists found that there was a lot more blue and less green in the Pacific Ocean when compared to the previous year. This means that there was a lot less phytoplankton. They found that phytoplankton almost completely disappeared during the massive El Niño event that occurred from 1997 to 1998.
The new findings could lead to phytoplankton forecast models. This could allow scientists to better understand how many fish may be in a given area during an El Niño event.
Currently, the researchers are looking to determine which individual species of phytoplankton will bloom where, based on nutrient amounts, temperatures and other factors.
The findings reveal a bit more about the food chain in the ocean during El Niño years. This is extremely important when it comes to fish catches and fisheries.
