As If Someone Pulled The Plug On The Estuary

A fisher casts his net in the estuary Sunday

Saturday, the waterways of San Jose del Cabo's principal natural feature, its lush freshwater estuary, began to gush into the Gulf of California. Sunday, the draining continued, reducing the lagoon's broad and lazy channels to slim and quick-running streams flanked by expanding mudflats. The carcasses of thousands of fish littered the banks. For scores of pelicans, buzzards, egrets and osprey, Thanksgiving had arrived. The easy catch also was welcomed by local fishers, who arrived by the dozen, waded into the receding water and hurled their nets at schools of fish clustered in dwindling eddies. Virtually every cast was successful, though the fishers generally discarded the stout black fish that looked like some kind of bass while keeping a sleek silver variety about as long and fat as a good-sized trout.

This phenomenon of the disappearing water was new to us. As we strolled along estuary paths that had been underwater just a short time ago, a longtime resident of San Jose del Cabo paused to explain what appeared to be happening. As water in the estuary rises from both winter rainfall and discharges from the city's sewage-treatment plant, pressure builds along the high and wide wall of sand separating the estuary from the Gulf of California. That pressure, coupled with a high tide, is enough to breach the barricade, sending surging water from the estuary into the gulf. This happens once a year or so, he indicated.

The estuary is a birdwatcher's paradise, even on ordinary days. But this weekend the number of birds was exceptional. Our acquaintance on the estuary path even pointed out a Belding's Yellowthroat, a tiny and fidgety warbler whose sunny coloring is set off by a dramatic black mask. According to BirdLife International, the marsh at San Jose del Cabo constitutes a rare and prized habitat for the bird, but it's jeopardized by fires, drainage, reed cutting, intrusions of urbanization and the occasional hurricane. I've no idea what impact this weekend's abrupt siphoning will have on the Belding's Yellowthroat, but at least for awhile it will be easier to stroll about the estuary in search of the bird.