Deep-sea Ecosystem Engineers

Tube worms living at deep-sea oil seeps in the Gulf of Mexico significantly alter their habitat, similar to beavers altering the flow of a river. Researchers from Pennsylvania State University have just published an important finding in the journal Ecology Letters.

A computer model of tube worm aggregations was created for Lamellibrachia luymesi, which is among the longest lived animals known. Both actual and model populations persist for centuries and take up high quantities of sulfide from seep sediments.

Tube worms live off sulfide (the toxic chemical responsible for the smell of rotten eggs) by supplying it to internal bacteria which use sulfide as an energy source. To acquire sulfide, this tube worm grows “roots” through carbonate rock and into the sediment below. The roots deplete sulfide from the sediment, effectively preventing sulfide from seeping into the bottom water.

Once the levels of toxic sulfide are reduced, the habitat provided by the bush-like aggregations is made available to deep-sea animals with lower sulfide tolerances.