Explain: How does forests being destroyed mean that sediment levels will change...(WEBSITE-->)?

http://www.microactive.net/GBA/PapuaNewGuineaCaseStudyRevision.ppt#268,11,Sissano Lagoon



Click on the screen 4 times to get the 4th point



I do not understand the 4th point



What is sediment levels?



How it get rid of coral reef?



Explain it in very simple terms pleaseExplain: How does forests being destroyed mean that sediment levels will change...(WEBSITE--%26gt;)?
Sir H is spot on.

the extra soil in the water will kill the coral in two or three ways.

1 the soil actually glogs the coral and covers it up. the coral feeds by filtering food through ';fronds'; and if blocked with soil it can'y do this. ,most living things don't like being covered in earth.

2 the soil makes the water very cloudy. Modern corals rely on clear water allowing photo synthesis in the ocean allowing algae and plants to grow. Too cloudy and less or no photo synthesis.

3 The extra soil can alter the pH of the water. with the soil other biological material is washed in, bits of plant and animals etc. Bacteria feed on this and as a byproduct increase the acid levels in the water.Explain: How does forests being destroyed mean that sediment levels will change...(WEBSITE--%26gt;)?
well the .ppt slide certainly is not very clear, I understand why you're confused.



I would guess that what it is trying to say is that

1) some region of forest was clear cut

2) this caused more sediment (soil) to be eroded and carried to the rivers and lakes of the region. Trees and vegetation typically hold down soil, so removing the vegetation can allow the soil to be carried away by rain (especially in a place as rainy as Papua New Guinea).

3) the increased amount of soil in the water for some reason killed the coral reef. Not sure why this might happen, any marine biologists around?