What is a substrate control? Why is it done?
How is the evidence from a fire scene collected? What should be avoided?

The color contrast between the open ocean and the lagoon between the spit and the mainland. the greater concentration of suspended sediments in the lagoon gives the waters a more turbid appearance. the source of sediment in the lagoon is (are) [(rivers and streams from the mainland) (wind-borne sediment from the spit) (ocean waves washing over the spit) (all of these contribute)].