The shrimp welfare project

Apologies for focusing on just one sentence of this article, but I feel like it's crucial to the overall argument:

> ... if [shrimp] suffer only 3% as intensely as we do ...

Does this proposition make sense? It's not obvious to me that we can assign percentage values to suffering, or compare it to human suffering, or treat the values in a linear fashion.

It reminds me of that vaguely absurd thought experiment where you compare one person undergoing a lifetime of intense torture vs billions upon billions of humans getting a fleck of dust in their eyes. I just cannot square choosing the former with my conscience. Maybe I'm too unimaginative to comprehend so many billions of bits of dust.

The article mentions that issue in passing ("I reject the claim that no number of mild bads can add up to be as bad as a single thing that’s very bad, as do many philosophers"), but I don't understand the actual argument behind this assertion.

Personally, I believe that you can't just add up mildly bad things and create a very bad thing. For example, I'd rather get my finger pricked by a needle once a day for the rest of my life than have somebody amputate my legs without anesthesia just once, even though the "cumulative pain" of the former choice might be higher than that of the latter.

Having said that, I also believe that there is sufficient evidence that shrimp suffer greatly when they are killed in the manner described in the article, and that it is worthwhile to prevent that suffering.

Their point isn't that it's merely "worthwhile," but that donating to Sudanese refugees is a waste of money because 1 starving child = 80 starving shrimp, or whatever their ghoulish and horrific math says.