With a few clicks of the mouse, she summoned a map using satellite imagery of Sri Lanka and its territorial waters. Hundreds of blue dots congregated along the island country’s coastlines while others, isolated at wide intervals, were located farther offshore.

“Each of those blue markers,” she explained, “represents the last known location of a shark that we’ve tagged. The great white that you’re interested in is…that one right there.” She clicked on a dot in one of the clusters along the southern coast. An information window sprang up on the right side of the screen, displaying a photograph of a huge great white shark thrashing alongside the hull of a boat. Below this was a name, as well as the shark’s sex, weight, and length.

“Mary Jane?” Marty said, reading the name.

“We name all the sharks we tag. We also put them up for adoption. Would you be interested in adopting one, Marty? The money goes toward the purchase of new SPOT tags.”

“I’m afraid I simply don’t have the space for a shark on this boat.”

Elsa glanced up at him.

“It was a joke, Elsa. And sure, I’ll adopt one. But first things first.” He pointed to a button on the screen that read: MARY JANE’S TRAVEL LOG. “Can we have a look at that?”

She clicked the button. A new window popped up:

Mary Jane

Date tagged: Feb 26, 2019

Location tagged: Indian Ocean

103 days

7701 km

Filter track by: All activity / Week / Month / Year / 2 Years / Specific dates

Marty said, “Filter by all activity.”

She clicked again.

A yellow line appeared on the satellite map, tracing a meandering route along Sri Lanka’s southern coast. Elsa hovered the mouse cursor over the westernmost part of the line. A date and time appeared. “This is where Mary Jane was originally caught and tagged,” she said. “You can see that since then she took up temporary residency at hunting sites here, here, and here.” At the locations she indicated, the yellow line zigzagged chaotically. “Each are in relatively shallow shelf water, typically between five meters and one hundred meters deep.”

Marty pointed to the easternmost end of the line where it turned abruptly south and crossed the shelf break into the deep ocean. “What do you make of that? There wouldn’t be much food that far offshore, and it doesn’t look as though Mary Jane was striking out on any migratory route. She’s simply swimming back west, parallel to the coast.”

Elsa shrugged. “SPOT tracking is a relatively new technology, Marty, and we’re still trying to make sense of what we’re learning about the world of white sharks. If you want my best guess? Mary Jane was spooked from the last hunting ground. Believe it or not, great whites aren’t the ocean’s apex predator.”

“Of course they’re not. We are.”

“Yes, but humans aside, killer whales are king. Documented accounts of orcas targeting great whites date back decades, although the rising frequency of the attacks is a new development. Shark populations have been increasing due to restrictions on fishing, while global warming is expanding the geographical areas in which they can live. Another best guess? Sharks and orcas may simply be bumping into each other more often than they used to.”