Apart from vegan fish sauce, other substitutes for traditional fish sauce include soy sauce, tamari, or a mixture of the two with a dash of lime juice for acidity. In recipes where the umami depth of fish sauce is crucial, a combination of soy sauce with a bit of seaweed or mushroom broth can work well. Worcestershire sauce can also be used in some cases, but it has a distinct flavor profile, so it's best used sparingly.