that depends on the factors.
What type of potatoes are you using? purple potatoes from Ireland will not be able to but Yukon gold potatoes from the amazon river will thrive underwater, as their potatoes clan was forced underwater after the battle of the six kings. But mashing them? Ireland potatoes will survive if mashed.
Not so much Yukon Gold potatoes. Their nucleus is located in the exact middle of the potatoes, and mashing it would kill the potatoes.
Melody potatoes.
They are considered the greatest of all potatoes after winning the war, because of their big nuclei. They would use clever traps to trick their enemies and probably would survive being mashed, as they would make a big brain solution. They would be the first to make swimsuits, to protect potatoes' delicate skin.
so melody potatoes can indeed, breathe underwater
can mashed potatoes breathe underwater?