(i) Generally the areas along the sea coast are low lying and get flooded easily by the sea water during high tide.
(ii) This leads to accumulation of sea water over a long period of time leading to formation of swamps & marshes.
(iii) The tides help in maintaining the mangroves and the coastal biodiversity here.
(iv) Certain areas near the sea coast being low lying & waters being shallow also lead to sediment deposition by sea waves leading to formation of lagoons.
(v) In this way, at some places along the coast, the low lying areas turn into lagoons or marshy lands.