Saltmarshes

Question 1

What are they, and what conditions do they need to form?

Answer 1

Areas of flat, silty sediments that form in:
! Sheltered areas where deposition occurs OR
! Where salt and fresh water meet OR
! Calm conditions OR
! Large tidal range
! Large supply of sediment
! Flat

Question 2

What has to form first for a salt marsh to form? How do these form?

Answer 2

Mudflat; created by deposition of fine silts and clays in sheltered, low energy coastal environments. Massively aided by flocculation.

Question 3

Describe the formation of a salt marsh?

Answer 3

1) Describe what it is and conditions needed.
2) Flocculation to form mudflat.
3) Pioneer plants, such as eel grass, start to colonise the sward zone. They are halophytes, so can thrive in salty conditions.
4) Plants trap further mud, stabilises.
5) When the mud builds up and rises above the mean high-tide it becomes a low marsh.
6) New and more diverse plants can now live here, such as sea asters.
7) When it rises above the high tide it becomes a high marsh.
8) Vegetation succession continues and the soil quality improves, eventually forming uplands, where trees can colonise once the environment reaches it’s climatic climax.
9) Creeks can divide the saltmarsh.

Question 4

What are some threats to saltmarshes?

Answer 4

! Coastal areas are attractive for industrial, commercial and recreational use
! Rising sea levels
! Storms
! Any disturbance to supply eg dams

Question 5

Give an example of a salt marsh. Include the following info:
* Location
* Formation and some history

Answer 5

Keyhaven Marshes, in Southern Hampshire
* Formation linked to Hurst Castle spit
* Spit breached by storm damage, lead to marsh to retreat by 6m a year
* Coastal management put in place to protect spit and marsh.

Question 6

Why are they important?

Answer 6

• Protect land from erosion
  *Habitats