‘We are creating a world more like the late Precambrian than the late 1800s—a world where jellyfish ruled the seas and organisms with shells didn’t exist. We are creating a world where we humans may soon be unable to survive, or want to.’
– from Stung! On jellyfish blooms and the future of the ocean by Lisa-Ann Gershwin
There’s an extremely readable review/precis in the New York Review of Books that will whet your appetite for a tome on the unpromising sounding subject of plagues of jellyfish. It’s a good read, if somewhat apocalyptic in its conclusions. Towards the end Gershwin says
‘When I began writing this book,… I had a naive gut feeling that all was still salvageable…. But I think I underestimated how severely we have damaged our oceans and their inhabitants. I now think that we have pushed them too far, past some mysterious tipping point that came and went without fanfare, with no red circle on the calendar and without us knowing the precise moment it all became irreversible.’
The good news, kids, is that during the late Precambrian period there was a diverse fauna, including some which ‘may represent stem groups of modern taxa’. So it’s not, like, the end of the world. The bad news is, it took 500 million years from that point to reach conditions favourable to human life. Oh well.