Delve deep into squid territory

Jumbo squid invaded Orange County recently. The ten-limbed creatures, weighing up to 60 pounds, swarmed the waters near Newport Beach and anglers delighted at the prospect of calamari steaks. Bruce Robison, senior scientist at the Monterey Bay Aquarium Research Institute, talked about the life of squid and why we shouldn't be afraid of these marine cephalopods.

Why did this invasion happen in Orange County?

There has been a large-scale invasion of the California coast that started in 2002. We see peaks of squid in different places at different times but these are probably just local events. In 2002, the population of jumbo squid, which is also known as Humboldt squid, expanded north, up the California coast.

In Central California, the squid used to show up chiefly during the El Nino periods. When El Nino was gone, so were the squid. But in 2002, they moved in and they've been here ever since. Their home range is the eastern tropical Pacific. In the waters around their home range, they competed for food with tuna, sharks and others. Through fishing, we have taken out 90 per cent of the big fish that compete with the squid for food sources. So there has been a lot more food available for the squid. Also, those big fish fed on baby squid, so the predation has decreased. With those changes, population and home range are going to expand. The ocean is also warmer, which has made it easier for them to move into other areas.

What are the consequences of this movement?

They have a new impact. For instance, a type of fish called hake has plummeted in population. Hake are an important commercial species off the West Coast. From examining stomach contents, we know the squid are eating the hake. The hake population tanked and it looks as if it is going to stay that way. So the question becomes, what will the squid eat next?

Are the squid any danger to swimmers or fishermen?

No. I don't know of any legitimate stories of any humans being harmed.

How long do they live?

All squid have really short lifespans. A full-grown Humboldt squid lives for a maximum of two years. Lives fast, dies young.

Are they native to Pacific waters close to shore or do they typically stay down deeper?

Squid go where there is food to eat or where conditions are best. This month conditions might be nice in Newport, next month it might be Malibu. They are in Newport now because it just may be that there is more food there right now.

Are squid intelligent?

It's hard to gauge but we think they are relatively intelligent from what we know about octopuses — a very close relative. Octopuses can learn and they adjust their behaviour based on what has happened in the past.

How big can squid get?

We used to think Architeuthis was the biggest squid. It may grow as long as 50 feet. But another squid which was recently discovered — the colossal squid — it might be even bigger than that. The main body of a colossal squid is very big — maybe twice the size of an average human.

Then there's the jumbo squid — a really big one measures about 6.5 feet. About a metre for mantle length. Smaller ones, market or calamari squid — the whole length is six inches.

How do they defend themselves from predators?

Let's say there's a big swordfish coming; the squid can squirt a cloud of ink and swim away in the other direction because the swordfish can't see through the ink cloud. But they have other ways of protecting themselves. Some of their suckers, along their arms, are sharp. The squid would wrap its arms around the swordfish and stick it. The suckers are primarily for holding prey but they can be used against predators. They also have a beak, much like that of a bird — that's what it uses to eat food. But it can also use the beak against predators.

What fascinates you about these creatures?

They're big, they're fast and they can change colour. They can create patterns on their bodies. They can make circles, spots and stripes. The Humboldt squid are real masters at signalling back and forth this way. They are constantly talking to each other using a display of colours and patterns on their bodies. We know that's what they are doing but what we don't know is what it means. It is an alien communication that we would love to understand.