Life Aquatic A Perfect Storm of Warm

The bizarre consequences of a warming world can no longer be ignored.

- Allison Vitsky Sallmon

Every California diver I know has a recent story about when they first noticed things were changing at our local dive sites. Some recall their local kelp bed looking thin, while others mention the presence of yellowfin tuna on every shore dive, the range extension of a Mexican nudibranch or the appearance of a skinny baby sea lion on the swim step of their dive boat. For me it was when a three-metre-long smooth hammerhead shark curiously bumped my camera rig. It was August 2014, and it was no secret that the surface waters were a few degrees warmer than normal.

On that day the swell and wind were formidable, but we were determined to get offshore. We hoped to get a good look at the hammerhead sharks typically a subtropical species that had been spotted at the surface by one or two multiday dive boats over the past few weeks. We couldn’t believe our luck when one showed up and interacted closely (at times, very closely) with us for three hours.

Among divers the rumoured cause for the oddities of the summer of 2014 was El Niño (the warm phase of the El Niño Southern Oscillation), an ocean-atmosphere interaction in the east-central equatorial Pacific that strongly influences ocean conditions and weather patterns. However, the U.S. National Oceanic and Atmospheric Administration (NOAA) had not confirmed the presence of El Niño conditions. Meanwhile, Washington state climatologist Nick Bond had already come up with an alternate name for the odd patch of warmer-than-usual ocean off the coast of the Pacific Northwest: “The Blob.” This phenomenon, thought to be the result of locally persistent high pressure that inhibited normal wind-driven oceanic upwelling and cooling, had spread along the West Coast and encompassed multiple stretches of ocean from Alaska to Mexico.