TY - JOUR
T1 - A mark-recapture population estimate for invasive silver carp (Hypophthalmichthys molitrix) in the La Grange Reach, Illinois River
AU - Sass, Greg G.
AU - Cook, Thad R.
AU - Irons, Kevin S.
AU - McClelland, Michael A.
AU - Michaels, Nerissa N.
AU - O'Hara, T. Matthew
AU - Stroub, M. R.
N1 - Funding Information:
Acknowledgments We thank Denim Perry, Maurice Sisson III, Emma Trone, and Jared Woodcock for field assistance. We thank the United States Fish and Wildlife Service (USFWS) and the Illinois Natural History Survey (INHS) for providing floy tags for the study. Funding for this study was provided by the INHS, the United States Army Corps of Engineers LTRMP, the Illinois Department of Natural Resources, and the USFWS Federal Aid in Sportfish Restoration Program F-101-R. Josh Stafford provided valuable comments on earlier versions of this manuscript. The NTL-LTER program housed by the Center for Limnology, University of Wisconsin-Madison provided data for calculating the intrinsic rate of increase for rainbow smelt and rusty crayfish.
PY - 2010/3
Y1 - 2010/3
N2 - Invasive silver carp (Hypophthalmichthys molitrix) populations have expanded greatly in the Upper Mississippi River System (UMRS) since their introduction in the early 1970s. We conducted a Chapman-modified, continuous Schnabel mark-recapture population and biomass estimate for silver carp (106-901 mm) in the La Grange reach, Illinois River during 2007-2008. We estimated a total of 328,192 (95% CI 231,226-484,474) silver carp (2,544 per river km 1,792-3,756) comprising 705 (95% CI; 496-1,040) metric tons of biomass (5.5 metric tons per river km 3.8-8.1). Long Term Resource Monitoring Program (LTRMP) data from the La Grange reach showed an exponential increase in silver carp catches since 1998, with an intrinsic rate of increase approaching 84%. In 2008, silver carp comprised about 51% of the total LTRMP annual fish collection. To our knowledge, this large river reach may contain the greatest ambient densities of wild silver carp in the world. Our findings provide a target for reduction efforts and also emphasize the importance of the La Grange reach as a source population for potential expansion of the species to the Laurentian Great Lakes.
AB - Invasive silver carp (Hypophthalmichthys molitrix) populations have expanded greatly in the Upper Mississippi River System (UMRS) since their introduction in the early 1970s. We conducted a Chapman-modified, continuous Schnabel mark-recapture population and biomass estimate for silver carp (106-901 mm) in the La Grange reach, Illinois River during 2007-2008. We estimated a total of 328,192 (95% CI 231,226-484,474) silver carp (2,544 per river km 1,792-3,756) comprising 705 (95% CI; 496-1,040) metric tons of biomass (5.5 metric tons per river km 3.8-8.1). Long Term Resource Monitoring Program (LTRMP) data from the La Grange reach showed an exponential increase in silver carp catches since 1998, with an intrinsic rate of increase approaching 84%. In 2008, silver carp comprised about 51% of the total LTRMP annual fish collection. To our knowledge, this large river reach may contain the greatest ambient densities of wild silver carp in the world. Our findings provide a target for reduction efforts and also emphasize the importance of the La Grange reach as a source population for potential expansion of the species to the Laurentian Great Lakes.
KW - INHS
KW - Illinois River
KW - Silver carp
KW - Invasive species
KW - Mark-recapture
KW - Hypophthalmichthys molitrix
KW - Population estimate
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U2 - 10.1007/s10530-009-9462-z
DO - 10.1007/s10530-009-9462-z
M3 - Article
SN - 1387-3547
VL - 12
SP - 433
EP - 436
JO - Biological Invasions
JF - Biological Invasions
IS - 3
ER -