I should not have favorite springs, just like I don’t have favorite students, of course, but Madison Blue was one of my favorite springs.  I enjoyed all of the springs that I visited in their own ways, but Madison Blue had the perfect combination of breathtakingly blue water, an intimate feel (the vent and run were very small), and a lovely river at the end.

The headspring of Madison Blue.  The water really was that blue.

The limestone wall around the spring.  This wall was natural.

The short run of the spring into the Withlacoochee River.

The plume of Madison Blue Spring into the Withlacoochee River.

Madison Blue Spring was cold, only 20.8C or 69F.  It was the farthest north that I ventured on this project and only Wakulla Spring was equally cold.  Given its small size (22×25 m, according to the Scott et al. 2004, Springs of Florida), the 96 cfs discharge of Madison Blue seemed high and the velocity of the water in the little run was quick.  Like the other Suwannee River springs, the average nitrate concentration was fairly high (1.65 mg/L) and the phosphate concentration was fairly low (0.04 mg/L) for 2016 (http://www.mysuwanneeriver.org/portal/springs.htm).  The dissolved oxygen was not particularly high (1-2 mg/L), but not the lowest that I measured in this study.  There was algae, certainly, but the water clarity was really good.

Underwater view of the headspring of Madison Blue.

There were a few fish at the headspring, mostly sunfish (Lepomis sp.) and the occasional mosquitofish (Gambusia holbrooki) or shiner (Notropis sp.), but the fish were really abundant in the tiny run.

Sunfish checking out that camera in the Madison Blue run.

Shiners milling about in a backwater area in the short run of Madison Blue Spring.  And, of course, a curious sunfish.

Fish also aggregated near the plume of the spring.

The transition point from spring water to Withlacoochee water.

A startled spotted sucker (Minytrema melanops) fleeing the area where the spring meets the Withlacoochee.

In the end, the number of species observed and the diversity of the fish in the spring was relatively low (only 7 species), but the density of fish was comparable to springs on the Suwannee River.

After I finished collecting data, I paddled in the Withlacoochee a bit.  It was gorgeous.