File S1 - Of Travertine and Time: Otolith Chemistry and Microstructure Detect Provenance and Demography of Endangered Humpback Chub in Grand Canyon, USA

Contains Figure S1–Figure S5 and Table S1–Table S3.
Figure S1: Photo of travertine formations in Little Colorado River. Credit: C. Finch.
Figure S2: Discharge characteristics of the Little Colorado River near its confluence with the mainstem Colorado River, May 2009 – December 2012. A. Hydrograph. Lines represent the 6.5, 8, and 10 m3/s levels of discharge. Note the flashy storm hydrographs interspersed among very low base flow conditions. Data from U.S. Geological Survey National Water Information System (http://waterdata.usgs.gov/nwis). B. Flow frequency curve for Little Colorado River. C. Temporal patterns of flow frequencies less than 6.5 (blue), 8 (red), and 10 (green) m3/s in Little Colorado River.
Figure S3: Linear regressions of (A) barium:calcium ratios, (B) strontium:calcium ratios, (C) selenium:calcium ratios, and (D) ™13C, all vs. the percent of discharges within a month that was less than specified threshold values of 6.5, 8, and 10 m3/s.
Figure S4: Example of an otolith showing positions of ion microprobe ablations and corresponding δ13C data. The fish was collected on 23 July, 2010 in the mainstem; it was 24 mm TL and 63 days old. Note the rapid shift from elevated (Little Colorado River) to 13C-depleted values.
Figure S5: Humpback chub total length (mm) vs. age (days) at egress from the Little Colorado River to the mainstem Colorado River.
Table S1: Carbon isotopic ratios (δ13C, ‰) and C concentrations (ppm) in dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), and concentration-weighted average δ13C at Boulder Camp, most downstream sampling site in the Little Colorado River, and the mainstem Colorado River upstream of the Little Colorado. Absolute difference in δ13C between the two sites is computed for co-occurring dates.
Table S2: In situ carbon isotope analysis by SIMS (Secondary Ion Mass Spectrometry).
Table S3: Mean (± 95% confidence intervals) monthly temperatures, 2008-2012, in the Little Colorado River (LCR) and the Colorado River mainstem (Mainstem), 2008-2012. Difference between means is given as ΔT.
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