Along the coastline where mangroves grow is often shallow. Where the sea is shallow seagrass meadows are found. Seagrasses are a range of different flowing plants with grass like leaves that survive in the sea.
They survive from the low tide and how deep they grow depends on water quality and the species. Their roots bind the mud or the sand and reduce the erosion along the coastline. This also helps the mangroves to keep their roots anchored into the mud.
Like mangroves, seagrass meadows are an important home for many species of breeding fish and essential for a large proportion of juvenile fish. The tiny juvenile fish can hide among the seagrass. The rotting dead seagrass leaves are the food that starts a complex foodbweb.
Find out more: http://www.seagrasswatch.org/home.html