… Aquatic invasive species (AIS) have been making trouble for Lake Tahoe’s ecosystem ever since people started sticking them in there in the mid-1800s. Invasives crowd out native plants, starve out or prey upon native animals, and kick off disastrous ecological cascades. Increasingly, limnologists are finding alliances like that of clam and algae—in which aquatic invasive species create conditions that help other undesirables spread. They’re aided by a third accomplice: climate change. Warmer waters are worse for native species, and better for invasives and potentially harmful algae. At Lake Tahoe, native fish stocks have declined, toxic algae alerts have closed down beaches, and the celebrated waters are about 30 percent murkier than they were 50 years ago. The lake’s ecosystems, along with its multibillion-dollar tourism industry, rely on clear, clean, cool water. Tahoe—jewel of the Sierra, sacred space of the Washoe Tribe, and destination for nearly six million vacationers each year (including about a million from the Bay Area alone)—is at risk.