Data from: A three-stage symbiosis forms the foundation of seagrass ecosystems

Seagrasses evolved from terrestrial plants into marine foundation species
around 100 million years ago. Their ecological success, however, remains a
mystery because natural organic matter accumulation within the beds should
result in toxic sediment sulfide levels. Using a meta-analysis, a field
study, and a laboratory experiment, we reveal how an ancient three-stage
symbiosis between seagrass, lucinid bivalves, and their sulfide-oxidizing
gill bacteria reduces sulfide stress for seagrasses. We found that the
bivalve–sulfide-oxidizer symbiosis reduced sulfide levels and enhanced
seagrass production as measured in biomass. In turn, the bivalves and
their endosymbionts profit from organic matter accumulation and radial
oxygen release from the seagrass roots. These findings elucidate the
long-term success of seagrasses in warm waters and offer new prospects for
seagrass ecosystem conservation.