Tahoe Summit

The sky threatened to rain - and did briefly - and wildfire smoke filled the basin on Monday when I attended the Tahoe Summit. Because of this, my photo below is quite unlike the photos everyone else takes on vacation to Lake Tahoe.

It was fun to hear the Southern fire-and-brimstone preacher Al Gore speak about "winning the conversation" on global warming. But most of the morning's time was taken up by politicians thanking each other, and I was wondering if the summit was worth a five-hour drive.

Sudeep was hosting a delegation of Guatemalans to attend the summit and learn how private and public interests had come together to preserve Lake Tahoe. The hope is that they can do something similar to save their Lake Atitlan. I enjoyed meeting them over lunch, and the lab folks joined them for a tour of Lake Tahoe's research and environmental center. Okay, this was worth a five-hour drive.

Lake Tahoe is certainly deep now at about 500 m (1650 ft), but more amazingly, it is half filled with sediment, meaning it was very, very deep at one point (once deeper than Crater). Like Crater, Tahoe has a small watershed compared with its lake volume; hence, its waters hold a low proportion of sediment and are usually clear and blue. The long stick-like object above is a sediment core from Tahoe. You can see a white band near the bottom, which is the ash from Mt. Mazuma's eruption (that created Crater).

There was/is a native Lahontan trout, but fisheries management being what it was back in the day, of course they stocked with other fish. Ah, but if Lake Tahoe is a naturally unproductive ecosystem, let's also put in mysis shrimp to give the influx of fish more food. It turns out that the mysis shrimp ate the bigger zooplankton (about wiped them out), so there wasn't any net increase in available food, and now there is an invasive species to boot.

Christine is doing a project removing warm-water fish at the southern end of the lake, and I will be helping her in September. Apparently there is more development on that end, including a former wetland drained to create a neighborhood modeled after Venice. In the shallow and warmer Tahoe Keys, bass and blue-gill can survive. When I first heard that, my head jerked up. Why those are Florida fish! Why are they here?

There are invasive Asian clams and Kuagga mussels, too. And I saw a photo where the slopes of Lake Tahoe were once logged bare in an earlier century.

Luckily for Lake Tahoe, there were visionaries and politicians, yes. But as we drove around the northern end of the lake and sat through the summit speeches and toured the environmental center, I was acutely aware of how much money there was as well. Money and vacationers and a wealthy, resource-loaded country and the fact that five times less people live in the watershed than around Lake Atitlan. At the summit, they called Lake Tahoe a model for conservation, but it's going to be harder for other parts of the country - let alone, the world - to emulate. It'll take more desire, more creativity, more leadership, more community organizing.