El Niño and the seafood industry
It was in the 1600s when fishermen off the coast of South America noticed something strange –abnormally warm water temperatures during the Christmas season. This odd occurrence was later nicknamed El Niño or “Christ Child,” because of the seeming correlation to the religious holiday. Scientists now know that this phenomenon happens every two to seven years–and it looks like this year may be one of those years. The National Oceanic and Atmospheric Administration (NOAA) released an El Niño advisory this past March, and the U.S. Climate Prediction Center has stated that there is a 90 percent chance an El Niño will continue this winter and possibly even into spring of 2016. Tracking and predicting an El Niño is vital, as it has enormous effects on an array of commodities and their corresponding industries, especially along the coast of the Pacific Ocean where the economy relies heavily on fishing and agriculture.
The El Niño Phenomenon
El Niño is defined by NOAA as a prolonged warming in the equatorial Pacific Ocean when compared to the average water temperatures. In order to be considered an El Niño, there must be a three month average warming of at least 0.5 degrees Celsius. The presence of an El Niño can lead to weather changes all over the globe, including an increased rainfall, and can alter migratory patterns among many fish species. Many species of fish begin to migrate north towards cooler water, while surface- oriented fish may travel to deeper levels to get to cooler waters. Fish that do not migrate out of these affected regions tend to experience reduced growth rates, as they face challenges when reproducing and simply surviving.
NOAA has reported that there have already been multiple migratory changes this year for a variety of species up and down the Pacific West Coast. Equatorial game fish, such as mahi-mahi, have been captured off the coast of San Francisco. Swordfish, striped marlin and blue marlin have been observed off the coasts of California and Washington. There have also been sighting of movement for yellowtail, Pacific bonito, and albacore into more northern waters and more inland—which is interesting because these fish are typically found 100 miles offshore.
Changes in migratory patterns can directly affect the fishes’ traditional commercial fisheries. For example, market squid have traveled into cooler waters in the north, away from their normal location in California. Millions of adult sockeye salmon in the Bering Sea died as a result of water temperatures rising nearly 10 degrees Celsius this summer while the sockeye salmon were migrating back to their native streams.
An El Niño presence impacts the fishes’ food supply, too. During an El Niño, warm water is pushed up towards the surface, called an upwelling. This water, compared to the normal, cooler water, is less dense in nutrients. Those nutrients are the feed supply for plankton, and when there are no nutrients, plankton cannot thrive.
This has negative ripple effects, because plankton play a key role in the food supply for anchovies and other fish.
Fortunately, over the last hundreds of years scientists have studied this phenomenon.
As a result, governments can step in and take appropriate action to preserve their economies and aid their fishermen. Peru, for instance, has one of the richest fisheries off its coast. This century’s most devastating El Niño was in 1972-1973, in which many fish stocks in Peru took years to recover. However, since then the Peruvian government has stepped in to help control these fisheries and stocks have been able to recover more quickly after more recent El Niño’s.UB
Article contributed by Nicole Bessemer
18 • URNER BARRY’S REPORTER / VOL. 10, NO. 4 / FALL 2015