The Mediterranean Sea is key to the survival of the Atlantic northern bluefin tuna. It is the most healthy of only two breeding areas, and the waters surrounding the Balearic Islands are a vital spawning ground. Every year, the fish come to reproduce in the warm Mediterranean waters. And every year, an uncontrolled fleet of fishing vessels races to catch the tuna at this important and vulnerable stage in their life cycle, encircling whole schools with nets known as "purse-seines" .june 19, 2009, GP and the RW are in the central Mediterranean BFT fishing grounds to monitor the end of the purse seine fishing season and ensure the closure of the fishery will be properly enforced. .Here Greenpeace activist checking out boat fishing near to the maltese coast.