I thought the sea star 'melting' was a problem related to acidification?

[Scootaloo]

29. Trouble is, none of that would melt a starfish

Also, the killing is happening in the Atlantic, as well. strangely I've found nothing about it happening in Japan. Or the Kurils, or anywhere else in the West Pacific. it seems localized to North America.

While there is very likely some chemical component somewhere in the chain of events leading to a melted starfish (my money would be on acidification, leading to better conditions for parasites or compromised immunity on the starfish's part, rather than actual damage to the starfish through acidity), the acute cause is almost completely certain to be biological; an infectious or parasitic agent that feeds on or otherwise destroys the connective tissue that holds a starfish together.

if you had radioactive material in quantity enough to "melt" a starfish like that... everything else nearby would be melting, as well. Crabs, mollusks, fish, researchers...

It also doesn't seem to be affecting other echinoderms, that I can find. Granted, sea cucumbers, sand dollars, sea urchins, and crinoids aren't exactly charismatic or well-known.