The Salton Sea, seen from Obsidian Butte (click here for full-size version; note: 1 mb file)
Last week, I wrote about going to Anza Borrego for the Swainson's Hawk spring migration (as well as the plenty of other cool birds and wildflowers, too). We took one day of our trip to visit the Salton Sea, which is about 30 miles east of Anza Borrego (and over 200 feet below sea level). This "accidental" body of water is extremely important to birds for breeding, migration and wintering. Unfortunately, the Sea is drying up, and the increased salinity is killing the food sources for the birds. Various plans for saving the sea have been proposed but (as far as I know) no work has been done yet.
The Salton Sea, in its present incarnation, formed in 1905 when the Colorado river flooded and breached a dike along an irrigation canal. Millions of gallons per minute poured into the Salton Sink (an ancient dry lake bed). It took two years to stop the flooding, with the much of the effort funded by Southern Pacific railroad, which had some very important lines in the area. By the time it was stopped, 300+ square miles of land were underwater, including farmland, salt production areas and rail lines. Although the area had been dry for several hundred years before the flood, previous lakes had formed in the same location when the Colorado river changed course and flowed into the basin (itself the remainder of a larger inland sea).
After the flood was stopped, the Sea no longer received water from the Colorado, but it it still gets some inflow from some smaller rivers and from agricultural runoff. In the blazing sun of southeast California, the lake is losing more to evaporation than is replenished from these sources and it's rapidly drying up and shrinking.
Mixed flock roosting on small island
It's not surprising that birds would flock to the Sea, as it's situated along a major migratory route and obviously had held water for extended periods in the past. Additionally, many historical wetlands in California's inland areas had been drained and converted to agricultural uses, so remaining spots like the Salton Sea became more important.
The area to the left had been full of water just last year; it will probably be entirely dry by the end of this summer. While it was wet, it supported large numbers of ducks and other waterfowl.
During the Sea's heyday, all sorts of organisms flourished and provided plenty of food for birds. Fish (like tilapia) were stocked which further helped fish-eaters like pelicans, cormorants, grebes, et al. Though there is still very abundant bird life around the Sea, you can see signs of trouble everywhere.
There have been several major fishkills, and some significant bird die-offs, too, with avian cholera . And, as the water evaporates and the dry lakebed is further exposed, there is an ever-increasing problem with dust storms in the area - creating problems for humans and wildlife alike.
I am still learning about the Salton Sea myself, so maybe the best thing to do is include some links to information about possible restoration plans - from the Salton Sea Authority, and from California Audubon.
Caspian Tern casualty (with tilapia parts)
It wasn't all doom and gloom while we were there. We saw enough wonderful stuff to inspire us to get more active on the issue. To finish up, here's a sampling of the birdlife from our visit.
Swainson's Hawks foraging in tilled field (part of a flock of 38)
We started our day at the Cattle Call - a rodeo site in Brawley (a few miles south of the Sea). On the rodeo grounds and adjoining picnic area, we saw a nice smattering of desert birds (including some that I'd never seen in California) like Cactus Wren, Gila Woodpecker, Abert's Towhee (left), Gambel's Quail, Common Ground Dove and Black-chinned Hummingbirds. In a tall palm above the picnic tables, we found a pair of kestrels' nest (it helped that when we first spotted them, they were in flagrante delicto). The Swainson's Hawks that drew us to Anza-Borrego were here, too.
Over at the sea, we watched a small colony of Great Blue Herons at the rookery in some drowned trees just off shore. (Don't know if these trees were drowned in the original flood or at a later time.)
Great Blue Heron rookery
I managed to get a life bird at Obsidian Point, Yellow-billed Gull. The Sea is apparently the only regular, reliable place to see this species in the US. They are fairly abundant in summer when they arrive as post-breeding visitors, and one or two usually linger year round.
Yellow footed Gull and friends
One other attraction was geological - mud volcanoes. They're not really volcanoes in the blazing lava sense, but they are definitely full of mud. These bubbling pots of carbonated water and silt spontaneously appear around the area from time to time. (I'd heard something about them being related to the start of the San Andreas fault - anyone know about that?)
Mud Volcano... pretty cool
BTW, take a moment to check out dcoronata's diary on the spring migration in NYC area from yesterday (still time to rec it, even!)