The Celtic Sea Trout report.   http://celticseatrout.com/downloads/technical-report/

80 plus pages if you can dredge through it.  Does it provide anything new???

Just wonder what the cost was with the long list of 'scientists' involved/  Probably needs more research otherwise no grants/jobs any more.

From the Executive Summary:

"This task developed a general linear model relating adult sea trout rod catch per unit effort (for
England and Wales from 2000-2010) to catchment-scale environmental variables. Important
predictor variables were those of total catchment stream length, alkalinity and land cover by
coniferous and broadleaved woodland, and improved grassland. This shows that generally, shorter
rivers of low alkalinity in catchments which are relatively poor in nutrients and less-intensively
farmed, with good spawning and nursery areas easily accessible from the sea, tend to be the better
sea trout rivers. Conversely larger rivers whose headwaters are distant from the sea, with calcareous
geology and productive, more intensively-farmed catchments are more likely to be salmon and/or
brown trout dominated. Other exploratory analyses highlighted the importance of lower productivity
and calcium availability in creating favourable conditions for good runs of sea-trout. No significant
relationship was observed for total juvenile trout production in catchments and sea-trout rod catches,
indicating that sea trout production in rivers is driven by an innate propensity of trout to become
anadromous rather than density-dependant factors. Caveats relating to these models are that a large
proportion of the variation in sea trout rod catch between rivers is due to differing characteristics of
the fishery rather than the catchment, and increasing evidence from other studies that anadromy is at
least partly under genetic control."

Well I never I'm sure you never knew any of this did you?