 When a patch of the brown carpet algae is caged to keep both "S. nigricans" and other fish out of the patch, other species of algae quickly overwhelm the patch.This seems to indicate the brown carpet algae are dependent on "S. nigricans" for its survival.The presence of "S. nigricans" in ecosystems greatly increases the primary productivity of the area by boosting oxygen, nitrogen, and phosphorus concentrations.