If we lower the demand by not eating them, we can lower the supply taken from the ocean by self interested businesses trying to maximize profits. This ad increases consumer demand by framing consumption as good. It is far better to minimize our consumption of animals if we care about their lives.
I agree with the sentiment, but my experience of capitalism is that it would not cause reduction in resource exploitation. The reduced cost because of lower demand would just make it profitable to some other industry instead, who would use up the supply.
In some cases, you can even have the government intervene, like subsidizing production to avoid loss of jobs.
I upvoted the first comment, then realized it was ambiguous and undid it.
I'll go on record to say this advertising of eating living creatures we've purposely killed "so they don't go to waste" is disgusting on multiple levels.