#secchi disc

-- turbidity = the cloudiness of water or other fluids due to the presence of particles

-- large amounts of sediment, particles, or living organisms reduces light penetration

-- estuary and coastal water typically has greater turbidity than open ocean water

-- Secchi disc measures light penetration      -- white disc attached to a rope      -- lowered into the water until it is no longer visible      -- disc is raised until it is visible again      -- average distance is calculated

-- in areas with high turbidity / low light penetration, producers must live higher up to photosynthesize

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