Not good, not good at all

Sardines are a major intermediate pelagic fish.  That means that bigger fish eat them.  And as you might expect, we humans eat them too.  They were a big staple of the Cannery Row in Monterey, California, and certainly elsewhere up and down the West Coast of North America.

Not any more, apparently, as the West Coast sardine fishery is apparently mainly kaput.

This is bad for squid, seals, sea lions, bigger fish, seabirds of many kinds, cetaceans (dolphins, whales) -- just about all of the major consumers. 

And us.