Among catch and release fishing proponents, it is often repeated that fish blood doesn’t clot and if you release a bleeding fish, especially one bleeding from the gills, it will soon bleed to death, no matter what.
Now the “soda pop” cure is making the rounds, and here is a video showing what it is all about.
Stop bleeding fish
I don’t believe that fish blood doesn’t clot. Bleeding to death from any injury doesn’t make sense.
However, when it comes to bleeding gills, it’s obvious a fish could lose a lot of blood quickly and have a very poor chance of recovery.
So, I know there are real biologists here. What do you think of this Mountain Dew rescue idea? If the citric acids in the soda shut down capillaries as claimed, wouldn’t that just shut down the effectiveness of the gills completely and essetially suffocate them when released?
What about mouth bleeding? If a fish is bleeding in any way, should we give the injury a shot of soda, even if it means some gets swallowed?
Some googling shows mentions going back to at least 2007. This article may be interesting to you. (Be sure to note the follwup and the PDF.)
It’s clear that whatever the mechanism, the bleeding stops. The question is if you’re doing more harm than good.
That article and the followup seems to summarize other information available by googling.
First, fish blood does clot. It relies on thrombocytes instead of platelets, but it clots like the blood of other vertebrates. Apparently it clots faster in water than in air.
Various mechanisms have been proposed for the shut down of bleeding in the gills after the soda treatment. The most plausible one to me is that the carbonation produces a high CO2 environment around the gills, which causes vasoconstriction and slows blood circulation and hence bleeding. If this provides more time for clotting to take place then the fish will lose less blood. On the other hand, vasoconstriction will also mean it will be able to get less oxygen until the effect dissipates.
It’s not clear what is meant by “cauterization,” which sounds permanent damage rather than a temporary result. but it seems to me that the citric acid would be too weak to cause such an effect, and if it did it would be fatal to the fish.
That would be the issue. Without controlled studies of the long-term survival of fish that have been treated this way it’s impossible to say whether it is worthwhile.