Sunlight vs. Chemosynthesis Food Webs

Two Food Webs, Two Energy Sources

Simulation speed 1.0×

Camera orbit On

Legend

Sunlight — surface energy source Algae / plankton (producers) Herbivore fish Surface predator Vent chemical plume (energy source) Chemosynthetic bacteria (producers) Symbiotic tube worms Vent crabs / shrimp

Surface web: alive — sunlight flowing

Vent web: alive — chemicals flowing

Drag to rotate, scroll to zoom. Cutting sunlight collapses only the left (surface) web, base first; sealing the vent collapses only the right (hydrothermal) web. Neither cutoff affects the other scene — the two food webs run on completely independent energy currencies.

Why this works

Nearly every food web on Earth's surface traces its energy back to sunlight via photosynthesis. Hydrothermal-vent communities are a rare exception: chemosynthetic bacteria oxidize dissolved hydrogen sulfide from the vent plume to build organic matter, with no light involved at all. Some vent animals — tube worms among them — don't even eat; they host these bacteria internally and live off the nutrients the bacteria produce. Cut the vent's chemical flow and that entire web starves from the bacteria upward, exactly as blocking sunlight starves the surface web — but each collapse is local to its own energy source.

☀ SURFACE — photosynthesis

🌋 HYDROTHERMAL VENT — chemosynthesis