Well, starting in 2016 that is.
Guinness has been using fish bladders in its filtration for the past 256 years (yup, they have been around for that long). If you did not already know this, I am sorry for ruining it for you - I know 'fish bladders' is not the most romantic technique for filtration (in fact, it is quite stomach turning to really think about - especially when you read that particles of fish can be found in the final product). But, that is the past and time to move forward with Guinness and support their new venture into vegan-ville.
I, for one, am excited as fish product in my beer is not something I am too keen on. Cheers.
(tip: Next time you order a glass of Guinness, drop a shot of Chambord in there. The mix of both flavors are very tasteful.)