Based on Telling Our Way to the Sea: A Voyage of Discovery in the Sea of Cortez, by Aaron Hirsh. Farrar, Straus and Giroux, August 2013.
On a cloudless morning in late summer, five college students climbed from the sandy shallows into the open hull of a panga, a small skiff powered by an outboard motor, and departed the fishing village of Bahía de Los Ángeles, on the Sea of Cortez. Ordinarily, they would have gone out on the water with me—I was teaching their field course in ecology and evolutionary biology—but this was their day off, and they had hired a local to take them fishing.
From the stone terrace of the Vermilion Sea Field Station, I watched the boat carve a white V through placid water, heading straight toward the sun. It was early yet, and the small desert islands, the angels of Bahía de Los Ángeles, were dark silhouettes, afloat at the midline of molten sea and fiery sky. Five hundred feet from the beach, the outboard fell silent and the boat glided to stillness. Through binoculars, I watched my students drop fishing lines over the rails. At first I worried that their driver had decided to save gas, and this was to be their fishing trip. But when I saw a line come up twitching with a four-inch silvery fish, I realized they were merely gathering bait. After they had reeled in several dozen small sardines, the outboard started again, and they headed toward the islands and out of sight. I know what happened next because they told me about it later, when they returned to shore.
In the shadow of Isla Piojo, they caught two splendid yellowtail. Then came a third strike. The rod bowed and shuddered, but the young woman holding it managed to crank the line slowly in. From the way the fish was fighting, the guide judged it to be another large yellowtail. And indeed, when it came nearer the panga, he saw the flash of a silver flank before the jack dove hard, as they sometimes do when they first catch sight of the boat. Then, all of a sudden, the fighting ceased. Lamenting the loss of the big one, the young woman slipped the rod's long handle back into its holder.
Strangely, though, the rod remained ever so slightly arced, and several seconds later, the reel shrieked as line dragged out. With everyone, including the guide, taking a turn with the rod, the line was eventually reeled in. And when at last the guide plunged his gaff into the water, what he levered over the boat rail and let spill into the bow was a five foot squid, its arms writhing like a nest of snakes, the tubular body flashing blood-red. The guide clubbed it several times between its round, watery eyes, and finally it went still, the mucosal red skin fading to milky white.
A week later, back on campus, I received an alarmed email about another strange occurrence aboard a fishing boat, this one thousands of miles away, off the east coast of Japan. On the deck of Diasan Shinsho-maru, a ten-ton trawler, three crew members realized something was wrong when their winch creaked and groaned. Leaning over the rail, they saw the problem: the gathering net appeared to be full of slimy brown mud. Only it wasn't mud. It was jellyfish. Each creature was at least three feet across, and there were hundreds of them. The winch complained more loudly, the ship listed toward the laden net, and then capsized, tipping the trawlermen into the sea.
At first look, these events appear unconnected. They occurred on opposite sides of the planet. On the tree of life, Humboldt squid are as remotely related to Nomura jellyfish as we are. And yet, in another sense, the incidents are linked. They are signal cases of a phenomenon that has begun to unfold with increasing frequency in the world's oceans: The impacts of fishing are propagating through oceanic ecosystems in unpredicted ways. In the Baltic Sea and the South China Sea; in places once known for cod and others known for sharks; in the most productive waters and those less prolific—in short, all over the world, oceanic ecosystems have lately been tilting into new and different arrangements. Unexpectedly, some of these novel configurations seem to be stable in their own right. Various words have been used to describe the striking property: homeostasis; hysteresis; a certain dreadful stickiness.