Professor Craig Radford spoke on "How Nemo found his way home." using the sound of the reef.
Craig was introduced by John Beck.  Craig was born in Taranaki, went to Waikato University where he completed a Bachelor of Science and then went on to complete his PhD in Auckland.
Craig is the Associate Professor at the Institute of Marine Science at the University of Auckland.  Craig is particularly interested in the sensory physiology of fish.  He is also interested in the biological role of ambient underwater sound and in particular the role of soundscape ecology in the marine environments.
Craig did his research for his PhD at Lizard Island Research Station where he learned that underwater, noise travels a lot faster. 
Sources of soundscape include:
Geophone - eg. waves crashing on the beach and earthquakes.
Biophony - biological sources.
Anthropophony - man made sources.
Some fish make their migrations at night.  Studies Craig and his students have done show that fish are attracted to and navigate using certain sounds.
Our world is getting noisier.  The sounds that we are making is having a detrimental affect on animals.  These sounds come mainly from construction activities, tourism and shipping.  Examples of underwater recordings were played.  The contrast between the noise of a research vessel and a cargo ship is huge.  
Noise pollution is a major issue.
The take-home messages from Craig are that:
Nemo did not get a ride with NIgel.  Nemo used the sound of reefs to guide him home.
Jacques Couseeau was wrong, the underwater world is not silent.