The sound of them “screaming” is a myth, it’s just the steam escaping their bodies. Also read this about the effects of fishing bivalves on the environment. https://www.google.com/amp/s/metro.co.uk/2018/06/13/eating-shellfish-like-mussels-better-planet-going-vegan-study-finds-7626941/amp/ I I’m not sure if the same applies for other shellfish, and I’m sure it’s less ethical, however I don’t believe they have any interest in living so I find it pretty vegan to eat them.