Fish.
If you are talking about the Thames river that flows past the houses of parliament and tower bridge, nothing. You wouldn't want to eat anything brought out of that stretch of water.
That would be the River Thames.
The River Thames is the major river through London, cutting right through the middle of the city. There are many other rivers in London, such as the River Lee (or Lea) and the River Brent.
The river Thames (pronounced temz)
London is situated on the River Thames (pronounced 'temz'.
Thames River
You can find several industries along the River Thames that include power stations. Shipyards, Refineries, and food manufacturers are other industries along the river.
The Thames flows through London.
The River Thames has multiple confluences. One such is the confluence of the River Thames and the River Darent at Dartford.
The river Thames.
The river Thames is in England.
River Thames.
Both, depending on your own views. It can be a problem when it floods the banks and the houses along those banks. It can be an asset for it's beauty and tourism. The river Thames is an asset because its a toursit attraction's.Also to add to that,the river Thames allows the boats who have to cross the Thames an opportunity to cross the river to give food and drink.