Fresh Water vs. Salt Water

When it comes to the water you can actually drink as a human being, there’s no question: fresh water is the way to go! But if we remove that requirement, both fresh and salt water have a critical role to play for life on Earth, as well as for our own enjoyment. Which type of water offers the most benefits to you? When summer hits, are you more of a lakeside vacationer or an ocean beach-goer? If you keep aquariums, what kind of water is in your tank?

Choose your team, learn more about both water types, and see which type reigns supreme on Eyewire! The competition starts at 11 AM EDT on 6/20 and goes for 48 hours.

Your teams:

Fresh Water

  • Usually water with less than 1,000 ppm (parts per million) of dissolved salts, this makes up less than 3% of all water on our planet. And most of it is still in ice sheets and glaciers! So fresh water is very special, and very precious. Special trivia: for water with borderline salt content between fresh water and true salt water, this is called brackish water.
  • Fresh water ecosystems are broken down into lentic (lakes and ponds), lotic (rivers and streams), and wetlands (where water saturates or inundates the surrounding soil on a recurring basis). 41% of all known fish species on Earth live in fresh water ecosystems, or at least live there part of the time in the case of fish like salmon who migrate seasonally from the ocean.
  • Although we can only drink fresh water, not even all fresh water can be safely drunk! Leaving aside fresh water sources contaminated by human activity, a not-insignificant portion of fresh water contains excessive heavy metals, pathogenic bacteria, viruses, and parasites, or an unsafe pH level.

Salt Water

  • The overwhelming majority of Earth’s water is saline, but there are further distinctions we can make. At only 1,000-3,000 ppm, we can call it “salt water,” but it isn’t until you reach 35,000 ppm that you have water as salty as the sea. Mildly to moderately salty water exists beyond the ocean in small quantities, usually in certain lakes and sections of groundwater.
  • Water salinity varies according to many factors, but especially heat. Warmer water can contain more salt. This is why global heating is making our oceans saltier; but more benignly, it’s also why the lowest seawater salt is found in the Arctic and northern Pacific, while the highest salt levels are in the Mediterranean and Red Seas (where it’s quite warm and there isn’t much influx of new, less-salty water from other bodies).
  • How dangerous is drinking sea water, really? Well, don’t make a habit of it, not even in a survival scenario. Your kidneys can’t keep up with that much salt. To prevent severe health risks, you would need to also drink enough fresh water to flush all the salt out. But if a little bit gets down your throat when you’re swimming at the beach, don’t worry about it!


  • Starting Lineup – top 3 players on each team, who earn 75% of their score in bonus points
  • All Other Players – earn 50% of their score in bonus points
  • Winning Team – 20,000 additional points
  • Each Team’s MVP – 5,000 additional points

The winning team is determined by average points per player, with 2x weight given to Starting Lineup players. To qualify for any of the above bonuses or affect the team score, players must earn a minimum baseline of 2,000 points.