A Presbyterian isn't a veggie lover or even a sort of vegan. There is a lot of disarray over what a veggie-lover is and isn't, however no meaning of the term ever incorporates fish.
A vegan diet rejects all creatures, and fish are creatures. Hence, an eating regimen that incorporates fish, or an individual who devours fish can't be appropriately called a veggie lover. A Presbyterian isn't a veggie-lover and a vegan diet.