Can Largemouth Bass Survive in Saltwater? Osmosis Explained

Last update:
Ocean fishing pier.

Largemouth bass cannot live in saltwater; they need freshwater to survive. Exposure to saltwater causes the freshwater in their cells to drain, leading to dehydration. 

Freshwater fish like largemouth bass are tough and resilient. They can withstand significant water and air temperature fluctuations, survive off little food, and adapt to their surroundings. But they aren’t invincible.

While largemouths can survive for a short time in brackish water (salt and freshwater combined), they wouldn’t last long because they need pure freshwater to thrive.

Largemouth Bass in Saltwater 

States like Florida, Louisiana, and California all have warm freshwater and impressive populations of largemouth bass. It’s not uncommon for some largemouths to swim up or down rivers and find themselves in or near the ocean. 

As they get to the brackish water, their instincts will kick in and push them back to freshwater, but it doesn’t always happen. 

Largemouths that spend too much time in saltwater will dehydrate and die. This process doesn’t take long. 

The largemouth’s gills will swell, and they are unable to regulate their body temperature. The salt dries out their cells, making it impossible to produce enough oxygen.

After fishing in Florida for a few years, I caught largemouth bass in rivers and streams near the ocean. They would put up a minimal fight and appear half-dead when I landed them.

A big bass leaps, striving to break free from the lure, while a fisher holds tight to the line.

What Happens to Bass in Saltwater 

Largemouth bass can’t live in saltwater because their body completes osmosis, killing them. If a largemouth stays in saltwater, its body will quickly realize that the salt in the water is more than the salt within its body.

When the freshwater inside their body leaves their cells, osmosis occurs. If this happens, the fish will die.

Their cells will dry up from the salt water, making breathing impossible. As a result, they need to constantly perform osmoregulation regardless of their habitat.

In freshwater, the salt in a largemouth’s body is higher than in the water, so water can continually pass through their gills and body and lead to oxygen production. 

Plus, they can urinate as much as they need to prevent overhydration. Largemouth bass urinate to get rid of any excess water. This regulation process continually happens to keep the fish healthy.

Most freshwater fish will experience the same thing as largemouth bass in saltwater. 

The Kangy river near Bengal Bay has red mangrove forests in its salty waters.

What Happens to Bass in Brackish Water

As mentioned, bass can survive in brackish water longer than pure saltwater. Largemouth bass bodies commit to osmoregulation and remove the excess saltwater finding its way into their gills and kidneys. 

Their cells will still shrivel, but not as quickly as in pure saltwater. Largemouth bass will die if they don’t get to freshwater fast enough. Even the smallest amounts of saltwater are damaging for largemouth bass.

Frequently Asked Questions

Are There Bass in Saltwater? 

Striped and sea bass live in saltwater, but largemouth bass can only survive in freshwater. 

Can Freshwater Fish Live in Saltwater?

No, freshwater fish cannot live in saltwater. Their cells will shrivel and release all the freshwater to survive. Euryhaline species like salmon, drum, and certain trout can live in fresh and saltwater.

Do Largemouth Bass Go to the Ocean?

No, largemouth bass do not go to the ocean. They spend their entire lives in freshwater. 


Largemouth bass are freshwater fish. Despite its ability to adapt to its surroundings and survive challenging conditions, it has no answer to saltwater. When a largemouth swims in saltwater, osmosis takes over, the necessary freshwater leaves its body, and the bass dies.

Danny Mooers Avatar


1 thought on “Can Largemouth Bass Survive in Saltwater? Osmosis Explained”

  1. Hello there. Having a hard time finding enough food for my bass. I’ve recently purchased silversides as a food source. Should this be soaked in fresh water before I feed it to them


Leave a Comment