Does anyone in the know have figures for inland cormorant populations in relation to improving water quality of the same period, it might help to establish or dismiss any possible link?
You may well be right Steve, but unfortunately attempting to show such a correlation may well cause some to jump on the figures and imply a causal link between the two factors, which could be entirely wrong and thus miss another factor which is causally linked - the problem then becomes that people opt for the 'obvious' answer and don't even bother looking for the underlying cause!