The estuary "Río de la Plata" (River Plate)

The plural form of estuary is estuaries.

It is not the estuary that is removed , but sediment around the estuary that is removed , reducing the nutrients that the estuary is getting.

There are many estuaries in Ireland. The Shannon Estuary is the largest.

There are many estuaries in Ireland. The Shannon Estuary is the largest.

There are many estuaries in Ireland. The Shannon Estuary is the largest.

There are many estuaries in Ireland. The Shannon Estuary is the largest.

There are many estuaries in Ireland. The Shannon Estuary is the largest.

There are many estuaries in Ireland. The Shannon Estuary is the largest.

There are many estuaries in Ireland. The Shannon Estuary is the largest.

There are many estuaries in Ireland. The Shannon Estuary is the largest.

There are many estuaries in Ireland. The Shannon Estuary is the largest.

There are many estuaries in Ireland. The Shannon Estuary is the largest.

There are many estuaries in Ireland. The Shannon Estuary is the largest.

As far as I know, A river's mouth is simply called the 'river mouth'!