Channel catfish and freshwater drum population demographics across four large Midwestern rivers

Figures & data

Table 1. Commercial and recreational length-based fishing regulations (mm) for channel catfish on the Illinois River and studied sections of the Mississippi, Ohio, and Wabash rivers.

River	Commercial	Recreational
Illinois	>381 (pools 6–8)	None
Mississippi (IL & IA)	>381	None
Mississippi (IL & MO)	>381	>355.6, 20 fish/day
Ohio^a	>330.2, one fish ≥711.2/day	>330.2, one fish ≥711.2/day
Wabash^a	>330.2, one fish ≥711.2/day	>330.2, one fish ≥711.2/day

^a Gear regulations vary for commercial fishing on the Mississippi and Wabash rivers.

Figure 1. Map of the Illinois River and sections of the Mississippi, Ohio, and Wabash rivers sampled during 2017–2018 under LTEF using DC electrofishing. Lock and dams are represented by bold black lines perpendicular to rivers, whereas different sampling areas in unimpounded reaches are represented by thin double lines.

Table 2. Pools and reaches of the Illinois, Mississippi, Ohio, and Wabash rivers sampled by LTEF pulsed-DC electrofishing surveys during 2017–2018 with river kilometers (RKM), the number of sampling locations within each sample region (N), whether each pool/reach is impounded by a lock and dam (Y/N), and mean (± SE) annual discharge with gauging station.

River	Year	Pool/Reach	RKM	Size (RKM)	N	Impounded (Y/N)	Mean annual discharge (millions of m^3)^a
Illinois	2017–2018	Pools 3–8	460.3–0.0	334.7	174	Y	0.3 ± 0.02, La Grange Lock & Dam, IL
Mississippi	2017	Pool 16	777.3–735.8	41.5	15	Y	1.2 ± 0.07, Lock & Dam 22, IL/MO
	2018	Pool 17	735.8–703.4	32.4	12	Y
	2017–2018	Pools 19–21	660.6–522.9	137.7	51	Y
	2017–2018	Pool 25	440–388.5	51.5	18	Y
	2017–2018	Chain of Rocks	322.7–266.3	56.4	21	N
	2017–2018	Kaskaskia Reach	266.3–188.3	78	30	N
Ohio	2017–2018	Smithland Pool	1478.2–1364.7	113.5	42	Y	3.1 ± 0.1, Metropolis, IL
	2017–2018	Pool 52	1364.7–1511.2	33	12	Y
	2017–2018	Pool 53	1511.2–1549.0	37	15	Y
	2017–2018	Mississippi Confluence	1549.0–1578.8	18.5	12	N
Wabash	2017–2018	Terra Haute, IN	783.8–715.4	68.4	15	N	0.4 ± 0.02, Mt. Carmel, IN
	2017–2018	Palestine, IL	715.4–663.1	52.3	21	N
	2017–2018	Vincennes, IN	633.1–620.4	12.7	18	N
	2017–2018	Mt. Carmel, IL	620.4–564.9	55.5	27	N
	2017–2018	New Harmony, IN	564.9–507.7	57.2	21	N

^a Period 2002–2018.

Figure 2. Length frequency histograms (10 mm total length bins) for channel catfish that were collected during 2017–2018 in the Illinois River and sections of the Mississippi, Ohio, and Wabash rivers. Total fish collected (N) and mean total length for each river.

Table 3. von Bertalanffy growth coefficients with 95% confidence intervals by river location for channel catfish and freshwater drum collected in 2017 and 2018 (L_∞ = maximum length (mm), K = growth coefficient (years-1), and t₀ = theoretical age at length 0).

Species	River	L∞	K	t0
Channel catfish	Illinois	652 (589–779)	0.186 (0.119–0.254)	−1.056 (–2.045–−0.427)
	Mississippi	640 (583–712)	0.223 (0.173–0.282)	−0.444 (−0.779–−0.189)
	Ohio	544 (499–770)	0.343 (0.095–0.611)	−0.601 (−4.417–0.688)
	Wabash	644 (566–840)	0.223 (0.117–0.341)	−0.483 (−1.620–0.196)
Freshwater drum	Illinois	571 (507–674)	0.096 (0.064–0.137)	−3.598 (−4.974–−2.521)
	Mississippi	456 (435–479)	0.254 (0.213–0.300)	−1.435 (−1.774–−1.121)
	Ohio	633 (596–681)	0.111 (0.086–0.136)	−2.446 (−3.352–−1.821)
	Wabash	613 (560–697)	0.075 (0.057–0.097)	−5.088 (−6.177–−4.216)

Table 4. Population age range and initial and maximum ages used for the descending limb of the catch curve in the mortality analyses for 2017–2018 channel catfish and freshwater drum from four Midwestern large rivers.

Species	River	Age range	Initial age	Maximum age
Channel catfish	Illinois River	1–12	5	12
	Mississippi River	0–11	5	11
	Ohio River	2–11	4	11
	Wabash River	1–10	4	10
Freshwater drum	Illinois River	0–29	1	29
	Mississippi River	0–23	1	23
	Ohio River	0–27	2	27
	Wabash River	0–27	2	27

Figure 3. Graphs of von Bertalanffy models for channel catfish sampled with DC electrofishing during 2017–2018 in the Illinois River and sections of the Mississippi, Ohio, and Wabash rivers. See text and Table 3 for parameters and parameter descriptions.

Figure 4. Catch curves for channel catfish sampled with DC electrofishing during 2017–2018 in the Illinois River and sections of the Mississippi, Ohio, and Wabash rivers. Ages used for regression are shown in Table 4 (Illinois r² = 0.95; Mississippi r² = 0.96; Ohio r² = 0.79; Wabash r² = 0.92).

Figure 5. Length frequency histograms (10 mm total length bins) for freshwater drum that were collected during 2017–2018 in the Illinois River and sections of the Mississippi, Ohio, and Wabash rivers. Total fish collected (N) and mean total length for each river.

Figure 6. Graphs of von Bertalanffy models for freshwater drum sampled with DC electrofishing during 2017–2018 in the Illinois River and sections of the Mississippi, Ohio, and Wabash rivers. See text and Table 3 for parameters and parameter descriptions.

Figure 7. Catch curves for freshwater drum sampled with DC electrofishing during 2017–2018 in the Illinois River and sections of the Mississippi, Ohio, and Wabash rivers. Ages used for regression are shown in Table 4 (Illinois r² = 0.81; Mississippi r² = 0.72; Ohio r² =0.47; Wabash r² = 0.76).

Data availability statement

The data that support the findings of this study are available on request from the corresponding author, ALW.