Human Interaction

 

Image located at http://en.wikipedia.org/wiki/Image:Physalia_physalis.JPG

Negative

The man of war can harm the tourism industry.  Every year tourists avoid beaches where the Portuguese men of war have washed up on shore or have been seen floating in the ocean.  A lot of money is spent each year to treat people that receive stings from Physalia.  These stings are characterized by long, linear red marks and very intense pain.   

The Portuguese Man of War is also a potential harm to the fishing industry.  Fish harvests may be influenced by the men of war which feed largely on fish larvae.  If there is a large increase in the Physalia population, it may lead to a dramatic decrease in the larval fish available.  If larger numbers of fish are consumed on the larval stage, there may be less fish left to grow and become a food source for humans.

Positive

Portuguese men of war are a food source for some fish and crustaceans that are of commercial value and thus, benefit the economy as well.  Also, the man of war may fill a role yet to be studied that keeps the ecosystem in balance.