We rolled backwards off the skiff and into the cool waters of the Sea of Cortez. The winter plankton bloom had yet to begin, so the visibility was over fifty feet, good enough for us to clearly see the bottom twenty feet below us. We had chosen to snorkel here, now, because a feeding squadron of grey pelicans were making repeated dives in the area, and we wanted to see why. The answer soon became apparent as a gathering cloud of sardines occluded our view of the sea floor. As the school moved toward us we were engulfed in a cumulonimbus of fish. The clouds parted as the school reacted to a diving pelican, and revealed brief glimpses of the terrain below us before the fish coalesced back into their protective mass; no longer individual and vulnerable singles, but a huge single organism, too large to tempt the birds circling above.
Suddenly, the cloud of fish scattered from the bottom instead of the top, and in the clear water emptied by their flight, the reason became apparent; a school of large yellowtail jacks were stalking the sardines from below!
We drifted, barely breathing as we watched the drama play out below us. Thousands of sardines exploding away from an attack from below or above, and quickly regrouping into their protective thunderhead formation before separating again. It was like watching a flight of starlings or a vigorous display of the northern lights. Elemental, breathtaking and ancient, it was life and death for both the sardines, the pelicans and the yellowtail.
It has been many years since there has been this large a population of sardines in the Gulf. For several weeks we found schools of both sardines and mackerel in each cove and bay we visited. The large numbers of the small fish that we watched being consumed by pelicans, boobies, gulls and frigate birds will return next winter in the form of an expanded population of sea birds; their fertility bolstered by this sudden influx of protein.
Finally chilled we climbed back into the skiff and returned to Westward, where hot showers and lunch awaited.
Restored and warmed, we awaited the revelations of the afternoon.