College of William and Mary, Gloucester Point, Virginia, USA

A marine scientist marvels at connections between the cold war and slimy mudflat worms.

Having grown up on the coast of New England, my childhood involved a good deal of digging around in the intertidal mud, unearthing things that most people of good sense do their best to avoid — things such as slimy, slithering worms, which often bite or smell bad, or both.

Older but no wiser, I was delighted to come across a recent paper (E. Teuten et al. Mar. Ecol. Prog. Ser. 324, 167–172; 2006) that has cleverly extracted a surprising scientific result from studies of such mudflat worms.

As well as reminding me of my dubious childhood pastime, the work recalls the period in which I grew up, during the cold war, when much of the world lived in fear of the nuclear weapons then being tested. This work takes advantage of one legacy of those tests.

The bomb tests sent into the atmosphere lots of the isotope carbon-14, normally present only at low levels. This bomb carbon-14 subsequently made its way into the oceans, where it became incorporated into plankton. The plankton in turn sank and became part of the coastal mud, providing a home and a food source for marine sedimentary animals.

Mudflat worms are generally believed to ingest wholesale the nondescript sediment in which they live, yet the worms examined in this study contained more bomb carbon-14 than the sediment surrounding them.

Thus, it seems that the worms assimilate from the amorphous goop, material that has been deposited since the cold war and so is younger than the average age of the sediment. Presumably, they do so because the newer material is more nutritious, but how they extract it is unknown.

Makes me want to get back out by the sea with my bucket.