Several previous posts have discussed the ecological importance of the Salton Sea, particularly its effect on migratory birds. However, the Salton Sea is also home to a much less obvious endangered species, the tiny desert pupfish. Desert pupfish, which are less than 3” long fully grown, are an unusual species due to their incredible tolerance for extreme water conditions. The desert pupfish can survive at salinities of up to 70 g/L—more than double the salt concentration of seawater. This has historically allowed the desert pupfish to live in saline lakes, rivers, and marshes throughout the deserts of California, Arizona, Colorado, Nevada, and Mexico.
The first post on this topic established that the Salton Sea is an ecological oasis and one of the last existing stops in southern California for migratory birds along the Pacific Flyway. However, it was mentioned previously that there are many factors which are threatening this avian Eden. Each of these threats will be addressed in more detail individually, with the first being avian botulism toxin.
Avian botulism toxin is produced by the bacteria Clostridium botulinum. While the bacteria is commonly found in soils and wetlands, it will not produce the botulism toxin unless certain environmental conditions are met. In order for the bacteria to produce the toxin, it needs an anaerobic environment, warm temperatures, and a protein source. Do these conditions sound familiar? In the summer, low dissolved oxygen levels, high temperatures, and the presence of dead algae (protein source) in the Salton Sea provide an ideal environment for the growth of C. botulinum and the subsequent production of avian botulism toxin. Continue reading “The Bird is the Word, Part 2”