I was reading about the Lake Baikal Seals and got to thinking about this.
If I took a walrus or whale or dolphin or manatee or any other kind of sea mamman that normally lives only in salt water and put it in Lake Michigan, for example, could it live OK?
I mean assuming it could find food and such, and I realize manatees need warm water, but let’s ignore that for the moment.
Is the fresh water seal a unique thing that they developed or could any sea mammal go from fresh to salt water without issues?
If the food source was plentiful enough I’d think any cetacian or pinniped could live in freshwater. The food would have to be there. There are no marine mammals of any size +/- 50kilos in the great lakes because there is no food source. Otter and mink and other intercoastal species don’t really count in this because I don’t consider them marine mammals, even though they rely on it or their own survival.
There are several species of dolphin that live exclusively in fresh water, and several more that are marine but where some populations live their entire lives in rivers. The there are animals like belugas that are marine but where many individuals spend about half their lives in fresh water. Then we get the other whales that at least occasionally come into fresh water.
Whether there are issues with going from salt to fresh water is a matte of some debate. Certainly many baleen whales that have spent prolonged periods in fresh water seem to develop skin infections, but this may be because only sick animals spend prolonged periods in fresh water.
What we can say is that for the toothed whales the transition from marine to freshwater lifestyle has occurred so many times that there would appear to be no significant barrier. So it seems more likely that the baleen whales don’t live in fresh water because there isn’t the food to support them.
Manatees can live in either salt or fresh water. In Florida they live in salt water during the warmer parts of the year, retreating to freshwater springs and rivers in the winter. Manatees apparently do not actively drink salt water; when living in marine environments they periodically go to river mouths for fresh water.
I know there are kinds of Sharks that can live in freshwater and kinds that can’t. So I was wondering if it was a species adapting over time, or could any sea mammal be put in water of any type? As long as there was food and the water was the right temp.
I mean like could a seal or walrus swim up a river and live there just fine?
I thought that the problem of fresh water v. salt water was one of breathing (gills etc).
And since sea mammals breath air, it isn’t a big deal for them.
I seem to remember hearing from a trainer at a waterpark, probably Marineland in Niagara Falls, Canada, that killer whales need salt water to survive, I think he said it had to do with the stress of swimming and keeping afloat due to their reduced buoyancy in fresh water.
I would assume that other large marine mammals would experience the same effects.
I can’t cite this, but I believe there are some health issues for some creatures just based on the salinity of the water, as it provides buoyancy and their skin has adapted to it. Changing/cutting the salinity (fresh water) can result in skin issues for some ocean mammals.
Came back to add link from Institute for Marine Mammal Studies. Dolphins can suffer from parasites and worms, and skin
sloughing in fresh water. See Q and A number 19.
Salt water species don’t do well in fresh water. Although they can survive for some time, they will be exhausted by the lack of buoyancy in fresh water. Also, after a while their skin will start to slough as the fresh water does not support their skin or eyes and they can develop serious infections
That and, I think, swimming under water. A salt water fish put into fresh water has trouble swimming. I’ve seen this in pet stores when a feed fish is put into a different tank for a predator fish.
The effect may only be temporary/they might adjust. I don’t know.
It’s a reptile, not a mammal, but ISTR that saltwater crocodiles, despite their name, can and do quite happily live in fresh water for long stretches of time. I don’t think it works the same way for freshwater crocodiles, though, but I could be (and probably am) mistaken.
I could have sworn we’ve had a similar thread before, maybe someone with better search-fu will find it.
Most marine mammals do just fine in freshwater. I have worked at (and still volunteer for) a marine mammal rescue center, and we keep our patients primarily in freshwater unless there are specific reasons (usually infections of the eyes or skin) not to.
While I was on staff there, we had an incident with two Humpback Whales swimming upstream from San Francisco Bay and into the Stockton shipping channel. This photograph: Page Not Found - Woods Hole Oceanographic Institution was taken a little more than 2 weeks into their adventure, and you can see sores and odd coloration in their skin (compare with this photograph: ba_whales002lm.jpg (image) taken about a week earlier.) Both whales were already wounded by propeller strikes prior to their sighting in the Bay, but the sores developed later and in areas of the skin not adjacent to the wounds. Something similar has happened to other Humpbacks that have spent lots of time in freshwater, but other species, like Gray Whales, seem less susceptible.
There are many species of marine mammals that spend large amounts of time in freshwater - ranging various river dolphins mentioned by Blake that spend their entire lives in freshwater to various pinnipeds, manatees, otters, and porpoises that are often found in freshwater or brackish water without any obvious ill effects. (Maybe non-obvious effects? If there are, we haven’t seen them.)
Others, like the Humpback Whales, seem to have more of a problem with freshwater. We don’t see them spend a lot of time in freshwater, so we don’t really know what the long-term prognosis might be.
I know the discussion hasnt been talked in in a year but considering straight dopes catchphrase.
Dolphins and whales alike can live in fresh water for limited amounts of time. Unless of course they are of the fresh water species. Same goes for manitees, sea lions, seals, etc. etc… i believe its anything up tp two weeks at the longest before major complications arrise. Oh and vandal if you ever read this im not trying to be a jerk when i say this but if you had ever been to sea world you would know that the animals all live in salt water hence the name SEA world. I live in san diego and have been to sea world so i really do know. Shamu splashing 52 degree water thats full of salt in your face tends to dry quickly in california sun leaving behind white salt streaks on wherever you get splashed.
As has been pointed out by several posters above, some species are quite happy living in fresh water for much more than two weeks (not just freshwater species), including belugas, some dolphins, and manatees.
Would water intoxication become a problem for some marine mammals living for prolonged periods in fresh water?
After all, most of them are presumably able to hydrate by drinking saltwater, which would probably mean that their bodies are adapted to the presence of much higher levels of sodium than most land mammals.
I assume that’s why those sea lions in the freshwater lake have to be given salt tablets with their food.
The sea lions in the Columbia below Bonneville dam are a huge problem. Some of the ones that have been relocated bore tags from as far away as San Fransico. So they really don’t have any problem adjusting between salt and fresh water.
