Why did fish move onto land?

[Beaker]

One of the big debates in evolution is why did fish move from the sea onto land? What possible reason could they have had to leave the safety of the seas? A new study of Blennies in the Cook Islands is showing a reason why they may come ashore....shedding light on the age old question:

http://www.mnn.com/earth-matters/animals/stories/fish-found-leaving-sea-evolve-land-animals