- BuyStung! On Jellyfish Blooms and the Future of the Ocean by Lisa-Ann Gershwin
Chicago, 424 pp, £19.50, May 2013, ISBN 978 0 226 02010 5
Near the end of H.G. Wells’s The Time Machine, the Time Traveller finds himself on a desolate beach in the distant future. Under a lurid red sky, by a slack, oily sea, he is set upon by giant crabs, last survivors in a dying world – ‘foul, slow-stirring monsters’, with ‘vast, ungainly claws smeared with an algal slime’. If Wells were writing that scene today, the jellyfish would be a much better candidate than the crab for the part of the doomsday creature on the terminal beach. According to Lisa-Ann Gershwin’s disturbing book, the jellyfish is an ‘angel of death’, a harbinger of ‘planetary doom’ likely to be the ‘last man standing’ in what she describes as our ‘gelatinous future’.
Vol. 36 No. 8 · 17 April 2014
Theo Tait gives a compelling portrait of the jellyfish, and the threats posed by their increasing numbers (LRB, 6 March). However, his account of the jellyfish fossil record is inaccurate. The arrival of predators with hard parts occurred during the Cambrian, which was preceded by the Ediacaran. The Ediacaran fossil record is dominated by disc fossils, which were originally thought to be jellyfish owing to their shape, pliability and perceived evolutionary simplicity. This interpretation has since been shown to be incorrect for three reasons. First, the disc fossils have all been preserved showing the same side, which means that if they were jellyfish, they must all have been killed (or beached) perfectly face down, in contrast to modern beachings. Second, Ediacaran discs show no signs that they were capable of movement, and many possess rooting structures that indicate they grew in sediment.Third, possible tentacle-like structures in the fossils are symmetrical, in contrast to the interlocking tentacles observed when jellyfish are killed. As a result, Ediacaran discs are variously interpreted as rooting structures, microbial colonies or traces of the movement of other organisms – but never as jellyfish. While the Ediacaran may contain some cnidarian (the jellyfish phylum), there are no known medusae until the Cambrian, 60 million years after the age mentioned by Tait. Jellyfish do pose a problem for the future oceans, but their dominance of the oceans is not a return to the past.