The Science of Salt

Millions of years ago, dinosaurs walked the Earth and the Salton Trough was at the bottom of the ocean. The Salton Trough was part of the Gulf of California until four million years ago when sediment from the Colorado River built up and closed the gap.1 Today, there are 150 miles between the Salton Sea and the Gulf of California, but evidence of their former connection can be found in the soil.

The land around the Salton Sea is composed of minerals of marine origin; many of these minerals are salts. A salt is a compound made up of positively (cation) and negatively (anion) charged ions. Sodium chloride, known as table salt, is the primary salt in the ocean and it dissolves readily in water to form a sodium cation and a chlorine anion. Other chemical components of seawater include magnesium, calcium, and potassium cations and sulfate anions. The Salton Sea has many of the ions of seawater in addition to phosphate and nitrate nutrients from fertilizers that are flushed into the Sea.2 Together, the total dissolved salt content of a body of water is called salinity. Continue reading “The Science of Salt”

Sink or Swim (or Float): Water Quality and Salinity

Can you swim in the Salton Sea?

You are going to the Salton Sea this weekend. It’s the desert; it’s going to be really hot, so you want to know if you will be able to cool off in the water. Considering the massive fish die-offs and the occasional nasty odor for which the Salton Sea is notorious, you might be concerned about the safety of swimming in the water. You probably want to know the answer to two questions:

First question: Can you swim in the Salton Sea?

Answer: Of course you can! It’s full of water, it reaches a depth of 50 ft., and there are plenty of crowd-free beaches. Not only can you swim in the sea, but you can also float really well. There are approximately 55 grams of salt per liter of water (g L-1). This salinity is higher than the ocean, which has ~33 g L-1; thus the water is more dense and, with no waves, the relaxation potential is greater [1].

Second question: Should you swim in the Salton Sea?

Continue reading “Sink or Swim (or Float): Water Quality and Salinity”

A Thirsty Sea

Located in an extremely arid region, the Salton Sea is subject to high temperatures and low precipitation. Extreme evaporation alone causes the water level at the Sea to decrease 5.4 ft. every year [1]. Historically, the majority of the water inflows at the Sea have been from diversions of the Colorado River, inputs from Mexico, and agricultural discharges from Imperial, Coachella, and Mexicali Valleys. Without these vital inflows, the depth of the Sea will quickly decrease causing release of contaminants currently present at the bottom of the lake and increase in salinity to even higher levels. The current salinity at the Sea is about 54 g/L which is much higher than the salinity in the ocean which is on average 35 g/L. This high level of salinity will affect the habitability for fish at the lake where only tilapia species have been able to survive despite massive die offs.

Continue reading “A Thirsty Sea”