ANSWER 1

Sediment can build up on seagrass for a number of reasons. Seagrasses grow in sandy or silty habitats and are actually very good at trapping sediment as they can slow the rate of water movement down and particles drop out of the sediment. When there is a large storm, sediments can be moved by the wind and waves and cover up seagrass. Also as seagrass often grow in protected coastlines where rivers run into the sea, if there is erosion on the land that flows into the river and the coastal environment, this could bury seagrass. Coastal activties such as dredging can also introduce more sediment into the water which can be deposited on seagrass.

Climate change could effect the amount of sedimentation through a few processes. In some regions climate change is resulting in more storms or more extreme storms that could result in more sediments building up on seagrass. Also some regions such as NSW are having more flooding and river flow due to climate change which could result in more sedimentation in seagrass meadows, especially those that grow in estuaries.

Image credit: Ocean Image Bank, Jordan Robins

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