Pallid Sturgeon in the headwaters of Lake Sakakawea
Pallid Sturgeon in the headwaters of Lake Sakakawea
Pallid Sturgeon in the headwaters of Lake Sakakawea
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<strong>Pallid</strong> <strong>Sturgeon</strong> <strong>in</strong> <strong>the</strong><br />
<strong>headwaters</strong> <strong>of</strong> <strong>Lake</strong> <strong>Sakakawea</strong><br />
Ryan Wilson, Everett Nelson, Zac Sandness and Tyler Berger<br />
U.S. Fish and Wildlife Service<br />
Missouri River Fish and Wildlife Conservation Office<br />
Bismarck, North Dakota
<strong>Pallid</strong> <strong>Sturgeon</strong> Population<br />
Assessment Program<br />
• Implemented <strong>in</strong> 2005 <strong>in</strong> North Dakota<br />
(segment 4)<br />
• Confluence to <strong>headwaters</strong> <strong>of</strong> <strong>Lake</strong> <strong>Sakakawea</strong><br />
(~55 river miles)<br />
• 12 random bends sampled twice per year<br />
• Trammel nets, otter trawl, trotl<strong>in</strong>es, m<strong>in</strong>ifyke<br />
nets
Yearl<strong>in</strong>g Equivalents (<strong>in</strong> thousands)<br />
120<br />
100<br />
80<br />
60<br />
40<br />
20<br />
0<br />
Cumulative Number <strong>of</strong> Yearl<strong>in</strong>g Equivalents<br />
Stocked <strong>in</strong> RPMA 2<br />
1998 2000 2002 2004 2006 2008 2010<br />
Year Class
Hatchery Released <strong>Pallid</strong><br />
<strong>Sturgeon</strong> (HRPS) Captures<br />
2005 – 25 captured (19 TN – 6 OT) 2006 – 24 captured (18 TN – 6 OT)<br />
2007 – 40 captured (15 TN – 25 OT) 2008 – 78 captured (23 TN – 41 OT – 14 TL)
CPUE (Fish/100 m)<br />
0.20<br />
0.15<br />
0.10<br />
0.05<br />
0.00<br />
Mean CPUE <strong>of</strong> <strong>Pallid</strong> <strong>Sturgeon</strong> <strong>in</strong> Trammel Nets<br />
2005 2006 2007 2008<br />
Sample Year
2009 Fall Sampl<strong>in</strong>g
2009 Fall Sampl<strong>in</strong>g<br />
• 71 HRPS captured <strong>in</strong> 2 mile<br />
reach (one day)<br />
• Only 4 HRPS captured <strong>in</strong> <strong>the</strong><br />
previous 4 years <strong>in</strong> this area<br />
• 8 <strong>of</strong> 11 year classes sampled
CPUE (Fish/100 m)<br />
0.20<br />
0.15<br />
0.10<br />
0.05<br />
0.00<br />
Mean CPUE <strong>of</strong> <strong>Pallid</strong> <strong>Sturgeon</strong> <strong>in</strong> Trammel Nets<br />
2005 2006 2007 2008 2009<br />
Sample Year
Discharge (m 3 /s)<br />
2000<br />
1800<br />
1600<br />
1400<br />
1200<br />
1000<br />
800<br />
600<br />
400<br />
200<br />
MO/YE Discharge 2005-2007<br />
0<br />
Apr May Jun Jul Aug Sep Oct Nov<br />
Date<br />
2005<br />
2006<br />
2007<br />
Average
Discharge (m 3 /s)<br />
2000<br />
1800<br />
1600<br />
1400<br />
1200<br />
1000<br />
800<br />
600<br />
400<br />
MO/YE Discharge 2008-2009<br />
200<br />
Apr May Jun Jul Aug Sep Oct Nov<br />
Date<br />
2008<br />
2009<br />
Average
Elevation (ft)<br />
1850<br />
1840<br />
1830<br />
1820<br />
1810<br />
1800<br />
<strong>Lake</strong> <strong>Sakakawea</strong> Elevations 2005-2009<br />
Max. Normal Pool Elevation<br />
Base Flood Control Elevation<br />
2005 2006 2007 2008 2009
2008 Headwaters
2009 Headwaters
Questions for 2010<br />
• Was 2009 a random occurrence?<br />
• Will <strong>the</strong> pallids still be <strong>in</strong> <strong>the</strong> same area?<br />
• Will <strong>the</strong> fish move up or down with lake<br />
levels?<br />
• Are <strong>the</strong>re pallids below <strong>the</strong> <strong>headwaters</strong>?
Discharge (m 3 /s)<br />
2000<br />
1800<br />
1600<br />
1400<br />
1200<br />
1000<br />
800<br />
600<br />
400<br />
MO/YE Discharge 2008-2010<br />
200<br />
Apr May Jun Jul Aug Sep Oct Nov<br />
Date<br />
2008<br />
2009<br />
2010<br />
Average
Elevation (ft)<br />
1850<br />
1840<br />
1830<br />
1820<br />
1810<br />
1800<br />
<strong>Lake</strong> <strong>Sakakawea</strong> Elevations 2005-2010<br />
Max. Normal Pool Elevation<br />
Base Flood Control Elevation<br />
2005 2006 2007 2008 2009<br />
2010
2010 Headwaters
2010 Standard Sampl<strong>in</strong>g<br />
• 345 HRPS captured; 2 Hybrids<br />
– 227 captured with trammel net<br />
– 71 captured with trotl<strong>in</strong>es<br />
– 46 captured with otter trawl<br />
• 102 captured <strong>in</strong> a 2 mile reach (<strong>headwaters</strong>)<br />
– 101 <strong>in</strong>dividual fish captured<br />
– One fish sampled twice
CPUE (Fish/100 m)<br />
0.5<br />
0.4<br />
0.3<br />
0.2<br />
0.1<br />
0.0<br />
Mean CPUE <strong>of</strong> <strong>Pallid</strong> <strong>Sturgeon</strong> <strong>in</strong> Trammel nets<br />
2005 2006 2007 2008 2009 2010<br />
Sample Year
2010 Headwaters
CPUE (Fish/100 m)<br />
1.0<br />
0.8<br />
0.6<br />
0.4<br />
0.2<br />
0.0<br />
Mean CPUE <strong>of</strong> <strong>Pallid</strong> <strong>Sturgeon</strong> <strong>in</strong> Trammel Nets<br />
Headwaters River
Meters<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
0<br />
Average Depth<br />
Pre July Post July<br />
Meters per second<br />
1.0<br />
0.8<br />
0.6<br />
0.4<br />
0.2<br />
0.0<br />
Average Velocity<br />
Pre July Post July
• August 16 – 18<br />
Targeted Sampl<strong>in</strong>g<br />
• Five Boats (3 MTFWP, 2 USFWS)<br />
• Drifted trammel nets<br />
• 244 deployments<br />
• 45,746 meters drifted<br />
• River mile 1558 -1553
2010 Headwaters
Targeted Sampl<strong>in</strong>g<br />
• 371 captures <strong>of</strong> HRPS<br />
– 344 <strong>in</strong>dividuals captured<br />
– 25 pallids captured multiple times<br />
• 112 different pallids captured <strong>in</strong> same area<br />
• All year classes represented*<br />
• Fish from all stock<strong>in</strong>g sites were captured<br />
– 77% from Yellowstone stock<strong>in</strong>g sites<br />
– 33% from Missouri stock<strong>in</strong>g sites
CPUE (Fish/100 m)<br />
1.0<br />
0.8<br />
0.6<br />
0.4<br />
0.2<br />
0.0<br />
Mean CPUE <strong>of</strong> <strong>Pallid</strong> <strong>Sturgeon</strong> <strong>in</strong> Trammel Nets<br />
2005 2006 2007 2008 2009 2010 Targeted<br />
Sample Year
Number Captured<br />
Thousands<br />
200<br />
150<br />
100<br />
50<br />
0<br />
80<br />
60<br />
40<br />
20<br />
0<br />
Numbers Sampled by Year Class<br />
1998 2000 2002 2004 2006 2008<br />
Numbers Stocked by Year Class<br />
1998 2000 2002 2004 2006 2008<br />
Year Class
Number Captured<br />
Thousands<br />
200<br />
150<br />
100<br />
50<br />
0<br />
80<br />
60<br />
40<br />
20<br />
0<br />
Numbers Sampled by Year Class<br />
1998 2000 2002 2004 2006 2008<br />
Numbers Stocked by Year Class<br />
1998 2000 2002 2004 2006 2008<br />
Year Class<br />
8<br />
*17,952
• 2009 was not a fluke<br />
Answers<br />
• <strong>Pallid</strong> abundance 4x higher <strong>in</strong> <strong>the</strong> <strong>headwaters</strong><br />
than <strong>the</strong> river<br />
• Aggregation followed <strong>the</strong> <strong>headwaters</strong> upriver<br />
• No pallids were captured downstream <strong>of</strong> <strong>the</strong><br />
<strong>headwaters</strong>
More Questions<br />
• Did we overstock some year classes?<br />
• What effect does this aggregation have on<br />
o<strong>the</strong>r fish species?
CPUE (Fish/100 m)<br />
1.6<br />
1.4<br />
1.2<br />
1.0<br />
0.8<br />
0.6<br />
0.4<br />
0.2<br />
0.0<br />
Mean CPUE <strong>of</strong> <strong>Sturgeon</strong> Chub <strong>in</strong> Otter Trawls<br />
2006 2007 2008 2009 2010<br />
Sample Year
How can <strong>the</strong>se f<strong>in</strong>d<strong>in</strong>gs help guide<br />
and ref<strong>in</strong>e future Missouri River<br />
Recovery Program efforts?<br />
• The stock<strong>in</strong>g program is WORKING!
How can <strong>the</strong>se f<strong>in</strong>d<strong>in</strong>gs help guide<br />
and ref<strong>in</strong>e future Missouri River<br />
Recovery Program efforts?<br />
• The stock<strong>in</strong>g program is WORKING!<br />
• More precise survival estimates<br />
– Population estimates<br />
– Adjust stock<strong>in</strong>g numbers
How can <strong>the</strong>se f<strong>in</strong>d<strong>in</strong>gs help guide<br />
and ref<strong>in</strong>e future Missouri River<br />
Recovery Program efforts?<br />
• The stock<strong>in</strong>g program is WORKING!<br />
• More precise survival estimates<br />
– Population estimates<br />
– Adjust stock<strong>in</strong>g numbers<br />
• Available river miles does not equal usable<br />
pallid habitat
Everett Tyler Zac
Tyler Ryan<br />
Landon<br />
Landon<br />
John<br />
Bob
Questions
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