Back in the winter of 2009/2010, the elusive Humboldt squid seemed to suddenly disappear from its usual habitat off the Baja California coast. At the time, marine biologists were baffled, but now they have an explanation for the jumbo squid’s rapid vanishing act – and it’s all down to El Niño.
El Niño is a climate pattern that occurs every three to seven years in the east Pacific Ocean. It lowers air pressure and brings warmer, less nutrient-rich water from the Indian Ocean to the Pacific Ocean.
Fish and giant squid alike don’t enjoy this, so emigrate to cooler waters with more nutrients. Every few years, the fishing business in the region is brought to a virtual standstill as most sealife temporarily disappears.
However, there’s something unusual about the Humboldt’s disappearance – it hasn’t come back. While most fish return, the giant squid is clearly enjoying its new home by the Midriff Islands, 100 miles north of the Baja California coast. Stanford University biologist William Gilly says, “It was obvious that the squid were pretty screwed up.” He adds:
“Squid can move to an area of tidal upwelling, which remains productive during an El Niño, and continue on their merry, giant-squid lifestyle and live to spawn when they are a year and a half old. It is comparatively meager fare and you will not get to be a big giant squid, so instead you reproduce when you are six inches long. It is a different strategy, but it works.”
But why have the squid made their vacation a permanent stay? Gilly believes it’s to do with the average lifespan of the squid, which has shortened since the move to Midriff Islands.
Whereas in normal conditions Humboldt squid live only 12 to 18 months, now the squid are only lasting six months before they reproduce and die. That means the generational memory is shortened – in other words, the Humboldt squid have forgotten about the luxuriant, nutrient-rich waters that are normally found around their old home.
Apparently the Humboldt squid population is slowly rising again off the Baja California coast, but the recovery is slow.