Did the squid warn of an earthquake?

Is it possible that squid can warn us of earthquakes? I say yes.

It was pointed out in the The Yomiuri Shimbun earlier this month that fishermen saw in increase of their catch of squid right before several major earthquakes, including this recent one in March 2011.

The article stated that “According to Agriculture, Forestry and Fisheries Ministry statistics, squid fishermen in Tokushima brought in 491 tons of the cephalopods in 1994–just before the Hanshin quake–which was 1.4 times the 1993 catch and 1.9 times the 1992 catch.”

This is certainly an impressive increase in catch. As it was also when “There were amazing hauls of squid just before the 1946 Nankai Earthquake,” one veteran fisherman from southern Tokushima said. And, most recently the correlation can be noted when just before the March 11 earthquake  “Squid fishermen in Tokushima Prefecture hauled in a bumper catch”.

Also, interesting was a small squid stranding right before a small earthquake in La Jolla, California in 2009.

Some questions have been asked that “if this increase in catch does occur right before a major earthquake has it ever been noted that there is a sharp drop in catch right after?” My instinct is to say that there would be a sharp decline in the catch since squid would not be as easy to catch. It seems to me that since this cephalopod is typically found near the bottom of the ocean floor (close to the Earth’s crust) they must be moving closer to the surface of the ocean where fishermen can catch them easier. According to a Tulane University website,  since earthquakes “occur when energy stored in elastically strained rocks is suddenly released. This release of energy causes intense ground shaking in the area near the source of the earthquake”. It would seem as though squid can detect the grounding shaking phenomenon prior to the rest of us since it happens in their own backyard first.

Bookmark and Share

What is the mystery of the chambered nautilus?

Year after year beheld the silent toil
That spread his lustrous coil;
Still, as the spiral grew,
He left the past year’s dwelling for the new,
Stole with soft step its shining archway through,
Built up its idle door,
Stretched in his last-found home, and knew the old no more
.”

Oliver Wendell Holmes (1804-1894)

The above is only an excerpt from the poem, “The Chambered Nautilus” by Holmes published in 1858. It only begins to hint at the marvel of this magnificent cephalopod. The chambered nautilus has become breathtaking subject matter for generations of artists and has become a commodity on the commercial trade industry.

The chambered nautilus is a squid that lives inside a shell marked with a brown and white zebra pattern. As the squid grows, the shell grows with it and creates compartments which are used as gas chambers and help the cephalopod rise or sink in the water column. The inside of the shell is lined with an iridescent pearl. In the last chamber of the shell are almost 90 tentacles and large eye peering out. Predators of the chambered nautilus include sharks, turtles, and octopus.

What makes the chambered nautilus so mysterious and sought after? Is it the mother of pearl that lines the inside of the animal’s shell? Is it that the animal represents a far off species only found tropical Indo-Pacific? Or is it that the inside compartments of the chambered nautilus each mirror its smaller and larger part exactly and therefore the animal is an example of the golden rectangle found in nature.

This harmonic progression is an illustration of Fibonacci’s sequence. This is a sequence where the first two numbers in the series are added to create the third number for a series of number that begins 0, 1, 1, 2, 3, 5, 8, 13, 21, 34 and so on forever. This proportional pattern can be seen all over in nature: flower petals, pine cones, and even galaxies. Below is an illustration of the proportion as it relates to the chambered nautilus.

Image (c) top – seasky.org, bottom – http://2muchfun.info

Do you have another interesting question? E-mail info@beachchairscientist.com and let us know what you always ponder while digging your toes in the sand!

Reference Squid

I would love to share this wonderful squid dissection video from Paul Dewiler, Instructor of Marine Science at the San Diego Mesa College. The video was inspired by his overview during his Ultimate Squid Dissection workshop at the National Marine Educators Associations 2010 conference in Gaitlinburg, TN. He states that the purpose of the video is to, “illustrate the squid’s external and internal anatomical structures so that teachers are confident and able to lead and assist their students in dissecting this species in the classroom”. As someone that has struggled with and watched other struggle with the dissection of a squid I am excited to share this wonderful resource. Thank you, Paul!