Surfing the internet is a crazy thing. One minute you are doing a google search on the newest smart phone, the next minute you find yourself down a rabbit trail of cat videos and Pinterest projects.
That’s where I found myself recently when I randomly came across an article on why freshwater fish can’t live in saltwater.
On surface level, I found the question a silly one. I mean, the reason is in the classification of the fish, right? FRESHWATER fish.
But the inner kid inside me said, “Yeah, but why can’t they?”
So imagine my surprise when 10 minutes, and multiple clicks and rabbit trails later, I realized the article applied to more than just fish.
You see, apparently there are 2 types of fish. There are stenohaline fish (fish that can only live in either saltwater or freshwater) and euryhaline fish (fish that can adapt to both environments). [Actually it’s much more complicated than this, but I don’t want to lose you this early. For more details, go here.]
You also have to understand osmosis for this to make sense. [Again, hang in there with me… I promise we’re headed someplace interesting].
Wikipedia says osmosis is a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one, thus equalizing the concentrations on each side of the membrane.
For the purpose of our discussion, the solvent (salt) passes between salty and less salty water, until both solutions are equally salty.
Back to our fish story…
In both categories of fish, the saline (salt) mixture in their bodies determines where they would thrive. Saltwater fish have a higher saline concentration than fresh water fish, but still lower than the seawater around them, so they absorb salt from the water to equal things out (and are comfortable in high saline environments- the ocean). Freshwater fish have lower saline concentrations than saltwater fish, but more than the freshwater around them, so they absorb water to equal things out (and so they are comfortable in freshwater environments- rivers, lakes, and goldfish bowls).
Do I see a hand raised in the back of the classroom? Yes, kid with the magnifying glass and the ant farm… what’s your question?
“What would happen if you put a freshwater fish in the ocean?”
Great question. Well, the salt in the sea water would begin dehydrating the fish by osmosis, and quickly its internal organs would begin to fail.
“So it would turn into fish jerky?”
Well, yes, I guess so… although that’s a bit graphic…
“And what would happen to a saltwater fish placed in a freshwater lake?”
Well, so that fish’s body has a higher salt concentration than the water, so it would begin absorbing water into its cells through osmosis, causing it to bloat up, and theoretically burst.
[Wait, when did that kid get in this story? I thought it was just us talking… can someone show him outside before he sets that desk on fire?]
So I’m reading this and something inside me clicks. This is not just a science-sy article on fish.
This is a description of how each of us interact with our environments. Our friends. Our families. And for many of us, our work.
Many of us can relate to times in our lives when we feel like a freshwater fish in saltwater, slowly being shrunk one molecule at a time, until we feel like a dried out husk of ourselves.
And just as many can relate to being a saltwater fish placed in freshwater, feeling like we’re absorbing everything around us, flooded with more than we can handle.
“But you said there was another type of fish. A Yuri-Haleen fish…”
Um, yes, a euryhaline fish. These are ones that have the ability to adapt to a wider range of salinities (salt water concentrations) by osmoregulating… a fancy word for that transfer of salt and water to keep things equal. But even these fish need time to adapt, loitering in their new environment long enough for their body to make the switch.
I believe these fish are like those people we all know who can be plopped into new environments, and with a little bit of time to acclimate, they seem to thrive, regardless of how different that environment was to the last one they were in.
But like fish species, I believe the number of these people as a percentage of the population is small, but they do exist.
“So what am I supposed to do with all this? I mean, why should I care?”
I think it is important for each of us to know what type of environments we are comfortable in, and to pay close attention to times where we feel like- I’m sorry- a fish out of water. If we feel like the environment we are in is slowly drying us out, or it’s overwhelming us with more than we can handle, it’s good to reassess whether that’s the environment for us.
And if were one of those special people who can adapt across multiple environments, we need to understand that while there will be stress, providing some time to get settled will allow us to feel comfortable there. But that time takes patience, so don’t lose hope along the way.
Now if you’ll excuse me, I have a a curious kid I need to relocate away from that bunsen burner…