Venice battles seaweed invasion

Venice is bracing itself for its summer tourist invasion, but an unwelcome newcomer has joined the thousands of visitors filling the Italian city.

While Venice battles seaweed invasion researchers say the voracious weed, undaria pinnatifidaea, it was probably brought to the Adriatic accidentally by a ship that dumped bilge water into the sea.

From the Adriatic it spread into the nearby lagoon and has now reached as far as the city itself.