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Pallid Sturgeon
Actinopterygii (ray‐finned fishes) Pallid Sturgeon: biology & Acipenseriformes (Sturg. & paddlefishes) techniques for monitoring a large Acipenseridae (Sturgeons) river fish Scaphirhynchinae Scaphirhynchus albus Scaphirhynchus: Greek, skaphe, ‐eos = boat + Greek, rhyngchos = albus: From the word albus, meaning white
Pallid sturgeon Life history • Long lived‐ • Identified in 1905 maximum age • They are unique among bony fishes because 50+ the skeleton is almost entirely cartilaginous • Up to 5 feet long • Bony scutes as armor • Benthic orien‐ tation‐adapted for swift velocities
Reproductive biology • Reproduce at 9 years old (~800 mm) • Reproduce in 2‐3 year intervals (Males) or 3‐5 year intervals (Females)
Switch to piscivory ~ 600 mm
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Preglacial period Postglacial period
Pallid sturgeon distribution Lake sturgeon
Pallid sturgeon
The combined Missouri‐Mississippi River, at 3,709 miles, the fourth longest river in the world, after the Nile, Amazon, and Yangtze
Shovelnose sturgeon
Shovelnose sturgeon distribution Lake sturgeon distribution
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Reproductive cycle
Spawning migration Eggs
Embryo hatch & drift Timeline
Pre 1900s
Embryos are intercepted & rear in shallow water habitats
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Channelizing The River Indian Cave Bend on the Missouri River near river mile 517, about 18 miles upstream from Rulo, Nebraska, illustrating the river before (1934; top photo) and after (1935, 1946, and 1977) the Wing Dike Construction at construction of brush Indian Cave Bend, Nebraska, Missouri River, dikes that narrowed and 10‐1935, Source: USACE channelized the river.
https://www.nap.edu/read/13019/chapter/4#32
Channelizing The River Elevated Flows
Sourece:https://lh3.googleusercontent.com/CqCwB6CLbVPUjmpPjjM2aqNWlJktKuqYu_0ixajc5dR9zqCqBrMfhGncUJWIFv aZpL431SWYwWWCwvVJSGEUHpDZIU7gGp9QEHCTjCWeWGBOclB6UePH31lYhAThkWtxvpfcqWJeIAM
Dynamic Habitat Embryo hatch & drift
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Timeline 1930s-1960s
Pre 1900s 1912 1944
Additional Dams… Additional Dams… 1. Fort Peck Dam Fort Peck Dam 3. Garrision Dam
4. Oahe Dam 6. Big Bend Dam
2. Fort Randall Dam 5. Gavins Point Dam
Additional Dams… Fort Peck Dam
THE MISSOURI RIVER—TOO THIN TO PLOW & TOO THICK TO DRINK
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Sediment delivery
Upstream dams allow sediment to settle out & increase water clarity Milk River
https://www.nap.edu/read/13019/chapter/4#37
Timeline
Endangered
Species
Pre 1900s 1912 1944 1990
Fish & Birds Timeline
Endangered
Species
Pre 1900s 1912 1944 1990 2000s
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Recovery program Habitat Restoration
"Channels of the Big Muddy" flickr photo by Plains and Prairie Potholes Landscape Conservation https://flickr.com/photos/plainsandprairielcc/8044354882 shared under a Creative Commons (BY) license
Habitat Restoration Restoration
"Dalbey Bottoms progress on March 29, 2012" flickr photo by Kansas City District https://flickr.com/photos/usace-kcd/6922442274 shared under a Creative Commons (BY) license
Floodplain connectivity Floodplain connectivity
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2003: Catch-Effort Monitoring Catch-effort based population monitoring • Began in 2003 • 2 Seasons – Sturgeon season (October to June) – Fish community season (June to October) • Standardized sampling – Multiple gears – Active & passive – Capture varying sizes
Sampling frame Sampling grain
Bends are defined as three contiguous habitat units, a channel cross‐over, inside bend, & outside bend
Sampling gears: Sturgeon season
1. Standard gears for Segments 1‐4 1. Trammel net 2. Otter trawl 3. Trotlines
Bends are defined as three contiguous habitat units, a M i ss o uri channel cross‐over, Riv e inside bend, & r outside bend
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Sampling gears: Sturgeon season Sampling gears: Sturgeon season
1. Standard gears for Segments 5‐7 1. Standard gears for Segments 8‐14 1. Trammel net 1. Trammel net 2. Gill net 2. Gill net 3. Otter trawl 3. Otter trawl 4. Trotlines 4. Trotlines
M M i i ss ss o o uri uri Riv Riv e e r r
Sampling gears: Fish community Sampling gears: Fish community
1. Standard gears for Segments 1‐4 1. Standard gears for Segments 5‐7 1. Mini‐fyke net 1. Mini‐fyke net 2. Trammel net 2. Trammel net 3. Otter trawl 3. Otter trawl 4. Trotlines 4. Trotlines 5. Pallid Sturgeon 5. Pallid Sturgeon gear of choice gear of choice
Standard gear to catch more sturgeon
Sturgeon & fish community Sampling gears: Fish community differences 1. Standard gears for Segments 8‐14 • No Gill nets‐stressful in warmer water 1. Mini‐fyke net • Fyke‐nets in fish community 2. Trammel net • Push trawl in lower segments 3. Otter trawl 4. Trotlines 5. Push trawl 6. Pallid Sturgeon gear of choice
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Fish size & gears Otter trawl
Experimental gill nets Mini fyke-net
Throat Box Lead
Panels vary in size: 1”, 1.5”, 2”, 4” Size selective catch
Trotlines
Good for mobile small bodied fishes. Typically set overnight.
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Trammel nets
Drifted downstream
Data collected Timeline
• Environmental variables Endangered – Velocity, depth, turbidity, temperature Species • Habitat type • Pallid Sturgeon Pre 1900s 1912 1944 1990 2000s Current – Length, weight, tagged, genetics, blood
Adaptive Management
2013: Recovery play includes an adaptive management plan… you need to monitor…
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Problem Modified monitoring program Current catch effort based monitoring may not be sufficient to Capture‐recapture program meet recovery 1. Bends sampled for 4 days (3 occasions) objectives, 2. Captured sturgeon marked estimate metrics needed to assess listing status, & Floy tag support adaptive management. PIT tag
Capture recapture Multiple occasions Day 1Day 2Day 3 • Shovelnose sturgeon are Floy tagged‐ only need tag retained for a short period of time • Pallid sturgeon are PIT tagged –less likely to lose tag • Use closed population capture recapture estimators to estimate bend level abundance
Capture histories
Cap Hist. 40 43 • Capture histories 100 84 108 Captured day 1 only • Estimate capture probability 110 9 9 Captured day 1 and day 2 – By size 101 3 7 Captured day 1 and day 3 – Environmental covariates (flow) 111 1 1 Captured days 1, 2, & 3 Bend Caught Abundance P1 P2 P3 010 127 212 Captured day 2 only 40 348 2005 0.048 0.073 0.063 011 8 5 Captured day 2 and day 3 43 553 4601 0.027 0.05 0.048 001 114 208 Captured day 3 only
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ECOLOGICAL CONTEXT
"Sub‐Adult Pallid Sturgeons" flickr photo by U.S. Fish and https://flickr.com/ph shared unde
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