Question

What challenges do aquatic organisms that inhabit or visit the bodies of water in estuarine areas have to face and adapt to?

Answer 1

The challenges by aquatic organisms that inhabit or visit the bodies of water in estuarine areas have to face and adapt to

a) Adapting to salinity : Osmoregulation i.e regulating the salt concentration of their body fluids.

For example if the salinity in water is lower than that of blood then the osmoregulators lose excess water via a active transport and absorb some of the solute molecules using gills, kidneys and other structures

Some of the bony fishes inhabit estuaries which also osmoregulate whose blood is less salty than sea water.

Salmon and freshwater eels also maintain stable internal environment via an active transport of solutes through gills, kidneys etc

Some of the soft bodied animals like molluscs maintain osmotic balance by allowing body fluids more or less irrespective of water salinity. These are called osmoconformers.

b) Adapting to mud : Some of the clams extend the siphon through the mud to get food and oxygen.