[MathGeek]

A colleague who is independently analyzing the data just emailed the attached graph showing the (negative) correlations between relative condition factor of the four species studied (spotted seatrout, red drum, black drum, and gafftopsail catfish) and the mean water temperature in the estuary over the 30 day, 60 day, and 90 day interval immediately before each individual fish was weighed and measured to determine its condition factor. This graph includes measurements from over 1100 individual fish covering 2011-2014.

The fact that all the correlations are negative suggests that fish thrive more in cooler waters in spring. (Measurements were in late May and early June.) Warmer water may increase forage availability, but it seems to increase metabolic costs by a greater amount so that fish tend to lose body condition in warmer water during spring and gain body condition under cooler water conditions. This temperature sensitivity seems to be the greatest in spotted seatrout and smallest in black drum.