A New Hunt Begins [S2Ep16 audio]

The Lepas anatifera is basically the spirit animal of this podcast. As we’ve discussed before, these animals live all over the ocean, and they attach quickly to anything that’s floating there, and they grow quickly in a predictable way, so just from the size alone you can tell how long something’s been afloat. Also, as the shells grow they incorporate minerals into their shells at a different rate depending on the temperature of the water. That provides a clue as to where in the ocean something might have floated from.So when the flaperon came ashore on Reunion in July of 2015, search officals were quite excited, because they realized they had new important evidence about where the plane had hit the water. But when they analyzed the shells, they were stumped. The barnacles were too small, meaning that they were too young. And not by a little! Based on what was known about barnacle growth rates at the time, it seemed like there was a year-long gap between how long the object had been floating and when the barnacles had started to grow.No one knew how to explain that puzzle. Maybe the barnacles grew slower that people realized. Or maybe there are predators in the ocean that strip a piece clean so they have to regrow.It looked strange, but since the data on Lepas growth rates was pretty thin, the authorities just shrugged. They assumed there had to be a reasonable explanation.Well, we don’t have to leave it at that. Because in fact there is tons of data out there just sitting there waiting to be collected.NOAA has over a thousand drifters floating around the ocean at any given time, and you can see them on the web. Click on a map, see the information on the drifter. The data includes where it’s been for every single hour since it was deployed, and what the water temp was, so each of those drifters has a population of Lepas that will let you correlate water temperature with growth rate.If you get a bunch of them you can also see how robust these correlations are — are they sometimes picked clean, or do they always have barnacles whose size matches the length of time they’ve been in the water.In today’s episode, I talk about my first effort to collect data from a NOAA drifter. It turned out to be a pretty wild ride! This is a public episode. If you’d like to discuss this with other subscribers or get access to bonus episodes, visit www.deepdivemh370.com/subscribe