Possible? Yes. Practical? That depends on the trident.
If we’re talking about a re-purposed fishing implement, then; not so much. Generally speaking, tools don’t make for particularly good weapons. If we’re talking about a barbed trident, that will actively work against the combatant when they’re trying to get the weapon back out of their opponent. It’s designed to catch and hold onto the meat it connects with. In a fight that is a very bad thing.
I’d also expect a fishing trident to
be produced of lower quality, cheaper, metals, since most fish aren’t known for
wearing heavy armor, and if you’re fishing for a living, money will be a real consideration. But, that would be my biggest concern there. Just
the overall quality of construction.
The design itself is sound. There were tridents designed for combat, and those evolved into an entire family of polearms, including Corsque, Spetum, and Ranseur. These abandoned the barbed tines in favor of blades. On the whole, these are a much sleeker weapons, designed for killing people, rather than collecting seafood.
It’s probably worth pointing out, the Romans used tridents in gladiatorial combat because they were inefficient, and would produce longer, bloodier, bouts. Not because it was a good weapon. After all, this was about entertaining the crowd, not killing people.