Assessing the migratory histories, trophic positions, and conditions of lake sturgeon in the St. Croix and Mississippi Rivers using fin ray microchemistry, stable isotopes, and fatty acid profiles

Ecological Processes

Table 2 Comparisons of sturgeon fin ray laser ablation data collected in November 2015 and March 2016

Fish ID	Fin ray portion	November Sr:Ca^a (µmol/mol)	March Sr:Ca (µmol/mol)	Relative percent difference (%)	March Sr:Ca/November Sr:Ca	Corrected November Sr:Ca (µmol/mol)	Corrected relative percent difference (%)
MNLKS20^b	Core	294	279	5.2	0.95	212	27.4
MNLKS09	Core	299	208	35.9	0.70	215	3.4
MNLKS11	Core	277	238	15.1	0.86	199	17.6
MNLKS15	Core	268	195	31.5	0.73	193	1.1
MNLKS16	Core	273	201	30.4	0.74	197	2.2
MNLKS25	Core	335	220	41.4	0.66	241	9.2
MNLKS25	Edge	368	281	26.8	0.76	265	5.9
MNLKS27	Core	292	213	31.3	0.73	210	1.3
MNLKS27	Edge	299	192	43.6	0.64	215	11.4
	Average	311	225	32.3	0.72	224	6.0
	Standard Deviation	44	33	8.4	0.06	32	5.7
	Standard Error	15	11	2.8	0.02	11	1.9

^aStrontium (Sr) to calcium (Ca) ratio
^bThis lake sturgeon was excluded as an outlier from calculation of mean ratio used to correct November data based on comparisons of linear regression analysis and relative percent differences among March data and both corrected and uncorrected November data
This value (bold) represents the multiplicative correction applied to Sr:Ca values for fin rays analyzed in November 2015 (group 1)