Percent cover all species

Percent cover of all fouling species over time. 0.5% indicates that the species was present but not detected in a point count grid method of 100 points on a photograph.随时间变化的全部污损生物（fouling species）盖度。在以照片上100个点为采样对象的点计数网格法（point count grid method）中，0.5%代表该物种存在但未被检测到。