Can Seals Live In Freshwater?
With the exception of the Baikal Seals that live in freshwater in the Caspian Sea, Seals live in the salty oceans. However, every now and then you can read about a Seal who swam up a freshwater river.
These rivers that the Seals were found in are freshwater, so Seals can survive in freshwater for some amount of time as long as there are fish to eat. I like to think that they also hunt for wild jello cubes, but I have never seen a jello cube outside of an aquarium.
So, what kind of water is in a Seal habitat at aquariums - freshwater or saltwater? Members of the "Alliance of Marine Mammal Parks and Aquariums" (an organization that comes up with guidelines for aquariums and marine mammal parks to follow to keep marine mammals happy and safe) keep water salinity (the amount of salt in the water) at not less than 22 Parts Per Thousand, per guidelines found at https://www.ammpa.org/membership/standards-guidelines. That is about 4 teaspoons of salt by weight for every 203 teaspoons of water by volume. In the open ocean, salinity is 35 Parts Per Thousand, and in freshwater the salinity is nearly zero. So, aquariums are supposed to keep Seals' water salty.
And still, some Seals spend an amount of time in freshwater and seem to be healthy, at least for a while. How does freshwater affect a Seals' body? It turns out, according to the paper "Osmoregulation In Marine Mammals" (https://jeb.biologists.org/content/204/11/1831) only 7 to 9 percent of the water Seals ingest for their diet is seawater. The rest of Seals' water in their diet comes from what they eat (fish), and this is freshwater. So, most of the water that Seals "drink" is freshwater, from fish. However, the same paper states that it is possible for Seals to die from having too little salt in their diet because it will cause their blood to have too little salt, which leads to unhealthy water retention and causes cells to swell, which can cause many health problems. So, Seals kept in freshwater will need salt supplements in their diet.
Seals in rivers probably have enough salt to stay healthy for a small amount of time, but they need to have salt intake after a while in order to stay healthy and alive. Or they need to be clever enough to capture wild jello cubes with just the right amount of salt.
These rivers that the Seals were found in are freshwater, so Seals can survive in freshwater for some amount of time as long as there are fish to eat. I like to think that they also hunt for wild jello cubes, but I have never seen a jello cube outside of an aquarium.
So, what kind of water is in a Seal habitat at aquariums - freshwater or saltwater? Members of the "Alliance of Marine Mammal Parks and Aquariums" (an organization that comes up with guidelines for aquariums and marine mammal parks to follow to keep marine mammals happy and safe) keep water salinity (the amount of salt in the water) at not less than 22 Parts Per Thousand, per guidelines found at https://www.ammpa.org/membership/standards-guidelines. That is about 4 teaspoons of salt by weight for every 203 teaspoons of water by volume. In the open ocean, salinity is 35 Parts Per Thousand, and in freshwater the salinity is nearly zero. So, aquariums are supposed to keep Seals' water salty.
And still, some Seals spend an amount of time in freshwater and seem to be healthy, at least for a while. How does freshwater affect a Seals' body? It turns out, according to the paper "Osmoregulation In Marine Mammals" (https://jeb.biologists.org/content/204/11/1831) only 7 to 9 percent of the water Seals ingest for their diet is seawater. The rest of Seals' water in their diet comes from what they eat (fish), and this is freshwater. So, most of the water that Seals "drink" is freshwater, from fish. However, the same paper states that it is possible for Seals to die from having too little salt in their diet because it will cause their blood to have too little salt, which leads to unhealthy water retention and causes cells to swell, which can cause many health problems. So, Seals kept in freshwater will need salt supplements in their diet.
Seals in rivers probably have enough salt to stay healthy for a small amount of time, but they need to have salt intake after a while in order to stay healthy and alive. Or they need to be clever enough to capture wild jello cubes with just the right amount of salt.
Comments
Post a Comment