Estuaries: Unique ecosystems

Estuaries are where fresh water from rivers meets and mingles with salt water from oceans. In estuaries, deposits of sediment at the river’s mouth forms fertile deltas.

Estuaries
  • are among the most biologically productive ecosystems on  Earth
  • are the source of a food web that begins with conversion of the sun’s energy into food energy by marsh plants
  • are home to only certain types of plants—those that can flourish in the physical conditions peculiar to estuaries
  • provide critical habitat for certain wild animals at some stage of their lives
A satellite image of the Salween estuary
In estuaries, fresh water is lighter than seawater and therefore flows above it. The nutrients carried in from the ocean in the river transform estuaries into very fertile areas for plant growth. In fact, estuaries are among the most biologically productive ecosystems on Earth.

Only certain types of plants can flourish in the physical conditions peculiar to estuaries, and each of these plants can grow in only certain parts of the estuary. One factor influencing the growth and distribution of plants in an estuary is its salinity, or the amount of salt in the water.*

Mangroves are a characteristic forest type in tropical river estuaries and a principle component of delta ecosystems. Mangroves not only act as a critical buffer to tidal storm surges, they provide ideal nursery grounds for fish species and support wildlife species.


* Copyright 2003 Canadian Wildlife Service & Canadian Wildlife Federation

Voices of the Dammed

Development in Burma

© 2017 Burma Rivers Network. All Rights Reserved.