NARRATOR：

Now listen to part of a lecture on the topic you just read about.

FEMALE PROFESSOR：

It would be great if we could stop the lake's salt level from increasing and save its fish and birdpopulations, but the solutions you just read about aren't realistic or practical.

First-sure, taking salt out of the lake by desalination would reduce salinity, but it would present some serious problems as well.

For example, as you've read, water pumped into desalination facilities evaporates and leaves behind solid materials that were dissolved in the water.

Well, the solid materials that desalination facilities leave behind would pose a health risk.

The materials would be mostly salt, but they would also include other types of chemicals.

Some of the chemicals would be toxic, like selenium.

If the wind spreads selenium and other chemicals into the air, and people breathe them in, that would be very dangerous to people's health.

Second, the idea of bringing ocean water into the lake.

Again, this would reduce salinity, but, as you've read, it would require constructing pipelines or canals.

The problem is that the local government may not have enough resources to pay for such major construction.

The nearest shoreline of the Pacific Ocean is 100 kilometers away.

Pipelines or canals are very expensive to build over such long distances.

As for the third solution-dividing the lake into sections by building a system of walls-well, that's unlikely to work for very long.

That's because the Salton Sea is located in a region that experiences frequent and sometimes intense geological activity, like earthquakes.

That activity would almost certainly destroy the walls separating the different sections.

So while this solution might work for a short while, the walls would likely collapse the first time there's a major earthquake, and water from the special sections with high salinity will mix back in with the low-salinity water from the main section.