Submitted to Biological Conservation, April 21st 2017.
The 3D plot is interactive (click and drag to rotate the plot).
The plot represents the densities of brown trout and cutthroat trout (z-axis; log10) in Logan River, Utah, from 2001 to 2016 (y-axis), at 5 locations in the mainstem (x-axis; x=0 at 3rd dam; x increases by going upstream; x=35.4 km at Franklin Basin). Densities are maximum likelihood estimates using 3-pass removal sampling which were aggregated over 1+ and older age classes. Densities were 2D-interpolated before plotting thus providing continuous values, between the most downstream (3rd dam) and the most upstream (Franklin Basin) sampling sites, and for the complete period (2001-2016).
This plot illustrates some important aspects of the status of brown trout and cutthroat trout populations in the Logan river that are mentioned in the paper:
1. brown trout (red) is dominant downstream where some cutthroat trout are still present (green-blue),
2. cutthroat trout (yellow) is dominant upstream with complete absence of brown trout (blue),
3. the location of the switch in species dominance looks fairly stable from 2001-2009, although possibly moving upstream more recently,
4. most density variation is of spatial nature (3D X-shape; to the exception of a drop of cutthroat trout density at 3rd dam in 2007-2008),
5. brown trout density at 3rd dam is the lowest in 2012 and cutthroat trout density is highest in 2012-2016; the mechanical removal took place a the 3rd dam reach in 2009-2012.