Water is carrying hidden loads from wreck TNT to plankton barter and phosphorus traps
TNT traces have turned up around North Sea wrecks. Open-ocean plankton are trading sugar for nutrients, and an unexpected mineral keeps holding phosphorus in oxygen-poor lake beds.
Science··Morning
Explosive residue is showing up around wrecks
A team from Aarhus University found traces of TNT in water, sediment, starfish, and mussel samples collected around wrecks off Rømø. About 15 percent of the roughly 10,127 wrecks in Danish waters date from the two world wars, and the team worked with navy divers who sampled directly around sites including the German submarine UC-30. The researchers still do not know how far the pollution spreads, but the present picture already shows that the munitions are not staying sealed inside metal hulls and are starting to leak into the local marine environment.[1]
In barren seas, sugar is being swapped for nutrients
Stable-isotope work on Collodaria colonies collected in the Mediterranean points to a quieter circulation system in the nutrient-poor open sea. Hundreds or even thousands of microscopic algae inside one colony make photosynthetic sugars, while the host returns protective compounds and nutrients. Because this fragile partnership cannot be maintained in laboratory culture, being able to examine it in the field matters: it suggests that productivity in barren waters rests not on one organism alone but on a whole cooperative package.[2]
Phosphorus does not automatically escape when oxygen disappears
Experiments at Concordia University show that when oxygen disappears and the usual iron minerals become unstable, the iron sulfide mineral mackinawite can keep holding on to phosphorus. That finding means nutrient loads in lake beds do not always return straight to the water column; in some anoxic environments a different mineral pathway takes over. Natural organic matter competes for the same surface and lowers the retention capacity, yet the result still shows that hidden loads in water are shaped not only by pollutant leaks but also by unseen chemical bonds.[3]
