Overall this paper has much to comment it. However I was disappointed that there was a lack of numerical data given in the results section, any reader has to depend on the figures, this needs to be rectified. In addition the results would benefit from and be much tighter if the discussion was removed and placed with the conclusions in a combined discussion/conclusions section. Finally the figure legends should be more expansive and stand on their own and not be dependant on the body of the text to support their interpretation.