Like all marine creatures, giant squid face the double whammy of warming water and ocean acidification (more carbon dioxide in the atmosphere drives a decrease in seawater pH). This can make it harder for all cephalopods — squid and their relatives — to breathe. …

But to Guerra, the greatest threat to the giant squid is fishing. No one catches giant squid on purpose — their flesh is unpalatable — but trawl nets bring them up anyway. Discarded at sea, these carcasses may later be washed ashore.