Editor's Note: William Gilly, a professor of cell and developmental biology and marine and organismal biology at Stanford University, is traveling with a group of students on board the Don José in the Sea of Cortez. They will monitor and track Humboldt squid and sperm whales in their watery habitats. This is the group's fifth blog post.

SEA OF CORTEZ—Yesterday we found the Humboldt squid, large and small, in plenty. The dozen huge squid brought aboard approached a quarter of a ton in weight, a quarter of the mass of our class of 10. Both hunters and scientists are now satiated. But a heavy heart has settled on some.

Lauren's first Humboldt squid

I chose my lucky fishing spot on the starboard side of the boat, where I had caught six small squid two nights before. Standing in the dank darkness by myself, I let my eyes go to night-vision mode and soon saw faint flashes of bodies stir up the bioluminescence as they attacked my jig. These darting squid were too small, so I let my line out until the glowing jig eerily disappeared into the abyss. I imagined it reaching an area of high giant squid traffic—the deep, where squid feed on myctophids and cephalopods that swim near the oxygen minimum zone. Seconds later, I felt a heavy tug. "Squid on!" As I reeled in the line faster and faster, my heartbeat kept pace. My comrades were catching squid left and right, but I didn't realize this until my squid thrashed its way onto the deck where several others already lay flashing their chromatophores like S.O.S. signals. In stark contrast to those deep crimson cephalopods, mine was chalk white on landing. As I scanned the dozen or so throbbing squid violently sucking air, my heart dropped. The thrill of the hunt dropped with it, turning into a nauseating realization: We were killing squid. This was not just a "science experiment" but mass carnage. Staring at my squid, its whiteness sent slivery shivers through my skin. Large knowing eyes stared back and its siphon gasped for water; I nearly picked it up and threw it back in. My gasps were from sadness, not the struggle for life felt by the squid. Was this science or sport? How much death is necessary in the name of science? Should questions like these riddle the minds and hearts of biological researchers, or should we detach ourselves from the emotions sparked by sacrifice?

Gilly's vision

Lauren's experience is not unique. Ten years ago, we started our work on Humboldt squid in the Sea of Cortez by catching, tagging and releasing a thousand squid in a week for a tag-and-recapture study. During this project, a small number of squid were attacked by others and cannibalized, rendering them unsuitable for tagging. These squid were thrown onto the deck of the panga by the fishermen who wanted to use them—fishermen waste nothing.

On one of those unnaturally calm nights when the Sea of Cortez was as silent as death, I looked down at a damaged squid tossed to the deck. The helpless creature exhaled with the sound of a dolphin, trying vainly to breathe in the foreign air. The skin pulsed red and sporadically flickered, gradually fading to pallid white as brain activity withered. During all of this, that cold, unblinking eye larger than my own glared upward from the deck. Although I had dissected thousands of smaller squid during my 30-year career, I was shaken.

That eye has haunted me for a decade. Perhaps the vision of death is necessary to fully embrace the value of life. This is the truth Ahab never grasped.

Our class has retired our squid jigs, at least temporarily, and we are embarking on a new week of exploration of the ecology of rocky intertidal habitats. For me, the quest for Humboldt squid will continue on a cruise in June in these same waters on a large research ship operated by the National Science Foundation. For now, the class will turn to the creatures on and under the rocks of the Sea of Cortez in some of the same spots visited by John Steinbeck and Ed Ricketts 70 years ago.

Image of squid courtesy of Lauren Linsmayer; image of sunset courtesy of Susan Shillinglaw