The clam production could be completely separated from the sea and then without harmfully interacting with very complex elements in the ecosystem and its diversity. Creatures without organ for processing information so in this aspect they cannot feel or prove a minimum sign of intelligence.
We recommend taking this evidence as it is and understand that clams and other alike species look simply perfect for being focused in terms of nutrition, avoiding other main sources of cruelty and interaction with those factors that could create a sense of guilt for different rational entities. Any individual should remember that being rational an action is the consequence of an individual decision, and those that cause harm are different. Everyone would guess assumptions, observations of this kind at any level of rationality, up to the highest.
Nature wants clams with a high iron content, with a handful of them surpassing the recommended intake per day so much more than others. As iron could be scarce in people trying to not put in their record actions that cause harm, this source seem interesting.