The Lagoon at Ligui

.

A large dry wash comes down from the mountains on one side of the town of Ligui.  A dirt road follows it out to the beach.  The scouring force of floodwaters has made a basin where the wash meets the Sea of Cortez, and the basin is separated from the sea by a long, semicircular sand bar.  There’s a little inlet, like a creek, that flows one way, then another with the tides.  At high tide, the sand bar is nearly gone.  At low tide, the lagoon has shrunk almost to nothing, and is probably only about 2 feet deep in the deepest parts—with great expanses of mud and sand exposed.

The lagoon has grown substantially since I first came here two years ago.  I hear there was a big hurricane last fall, with lots of rain.  A lot of sediment washed down, and expanded the size of the lagoon and pushed it’s sandbars a hundred feet or more further out into the bay.

Lagoons like this don’t form at the base of every dry wash.  Often, the surf destroys the sand bars which shelter the lagoon, pushing the sand back up onto the beach—amputating the lagoon.  But here, the water is calmer from the shelter of Danzante Island.

When you first see it, the lagoon isn’t very imposing—some might say ugly.  Unless, that is, the sunset is reflected in the lagoon, as it was when I first arrived this year.

The lagoon has few resources for humans.  The locals like to sit in the entrance creek, talking in groups.  Sometimes, you can see a man or  boy hunting for crabs with a stick about two feet long.  The upper reaches of the wash are used for dumping clam shells.  A dog will occasionally run along the edge or chase crabs.  The wet borders, where the sand is a bit firmer, make one pathway that cars can get to the beach.  But mostly, the lagoon is overlooked by humans.

At first glance, the lagoon looks dead—with the dead hulks of trees scattered around the edge, and a few in the center.  But the more I looked, the more life I found.

Most obvious are the herons—the great Egrets, Great Blue Herons, cattle egrets, and perhaps night herons that stalk through the shallows, or wait patiently in the shallows.  Gulls and vultures hang out around the edges, hoping for a larger dead fish to wash up.

There are usually schools of small fish in the lagoon.  At low tide, there are tiny fish up to an inch long, in water just an inch or less deep.   They dart around, then stop abruptly, depending on their camouflage.  There are schools of small minnows that ruffle the surface as they try to escape from your shadow.  And there are also schools of larger fish, perhaps 2-5 inches long, that also ruffle the surface with their evasive maneuvers, even when you’re still far away.

Once, at the height of fiesta on the beach, an osprey dove into the estuary, and made off with a large fish, fling low with its heavy cargo over the populated beach.  Almost no one noticed.  Today, I was watching an osprey dive repeatedly into the lagoon.  His steep dives were thrilling, but he always curved into a shallow dive as he approached the water, because it’s so shallow.  Sometimes, he would partly disappear underwater—but today he wasn’t successful.

There are greenish-brown crabs, with blue claws, up to 4-5 inches long.  At lowest tide, you can see thousands of small holes in the shallow pools, and also high and dry.  They are pulsing with flows of water—something inside is breathing  As described above, at least some of these critters are tiny lobsters, about an inch long.  Others may be marine relatives of earthworms.

Higher up from the lingering pools at low tide, you can see thousands of little balls of sand, where crabs (fiddler crabs?) have been sifting through the sand, for tiny bits to eat.  After each little bit of sand is processed, it becomes a pellet of sand.  I also saw some rather large holes for crabs, several inches in diameter.

I ambled up the dry wash, where I found the tracks of a raccoon-like mammal.  A few evenings later, I caught a whole family of them in my headlights as I returned in my car to the beach.

The lagoon area breeds a few small mosquitoes, and probably dragonfly larvae, because the adults are patrolling the beach.   At lowest tide, there is a small flow of water down the wash towards the pool, which may be fresh groundwater emerging.  If pools of this groundwater form somewhere back from the beach, that’s where the dragonflies breed.

One night, when I was landing my kayak, I was buzzed by a very large moth, one that had rapid flight.  It almost looked like a bat.

One day, an hour after sunrise, I explored the edge of the lagoon to see what had been happening at night.  The tide was going out.  Crabs up to 4-5 inches long were coming seaward, in anticipation of the lower water.  The pools were alive with fish—schools of one about an inch long, and smaller schools of larger fish, about 4-5 inches long.  The crabs and fish were extremely sensitive to my approach, heading for deeper water—so you can see why the ospreys have a hard time being successful.

Up in the dry sand, there are some large holes inhabited by crabs, and their tracks are all over the beach, along with those of gulls.  So the scavengers are very busy at night, cleaning up after the people.  But they don’t eat the plastic litter.

In sum, the lagoon is mostly overlooked by everyone, but it’s probably a nursery for many of the fish and other organisms in the Sea of Cortez.