Record Details
Persistence of Triploid Grass Carp in Devils Lake, Oregon
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Persistence of Triploid Grass Carp in Devils Lake, Oregon |
| Names |
Clemens, Benjamin J.
(creator) Spangler, John J. (creator) Robertson, Paul L. (creator) Galovich, Gary M. (creator) Banner, Craig R. (creator) Gunckel, Stephanie L. (creator) Ketchum, Lindsay L. (creator) Bowden, R. Kanani (creator) Spagnoli, Sean T. (creator) Kent, Michael L. (creator) Kirk, James P. (creator) |
| Date Issued | 2016-06 (iso8601) |
| Note | To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is published by the U.S. Fish & Wildlife Service and can be found at: http://fwspubs.org/. All material appearing in the Journal of Fish and Wildlife Management is in the public domain and may be reproduced or copied without permission unless specifically noted with the copyright symbol. |
| Abstract | Grass carp Ctenopharyngodon idella are sometimes used as a biological tool for managing aquatic vegetation in reservoirs. Sterile, triploid fish were stocked in Devils Lake, Oregon, during 1986, 1987, and 1993 to control aquatic vegetation. We present a case study for using multiple measures on the same fish to determine whether illegal stocking of fertile, diploid grass carp occurred. An investigation into the estimated age of a dead grass carp found in Devils Lake suggested that it was significantly younger than would otherwise be expected, given the only stocking events occurred during 1986, 1987, and 1993. To determine whether illegal stocking or reproduction by presumed sterile grass carp had occurred in Devils Lake, we conducted a study that balanced the needs of lethally sampling grass carp for biological measures with the socially and politically sensitive sentiment of the pro–grass carp citizenry of Devils Lake. These considerations, in combination with a low catch per-unit effort, resulted in a modest sample size for grass carp. We sampled grass carp and recorded multiple measures for each fish. Ploidy testing of blood samples indicated the grass carp were all triploid. Based on gonadal histopathology, six fish were male, two were female, and two were sex-indeterminate with severe gonadal dysgenesis. Age estimates from lapillus otoliths were consistent with fish originating from the legal stocking events in Devils Lake. The grass carp were 21–30 y old, and we were unable to find published reports of grass carp anywhere else in the world that are older. The grass carp were significantly smaller than much younger fish from other regions. The small size of these grass carp relative to their age in Devils Lake suggests food limitations that stunted growth. The dead grass carp that was the impetus for this study was aged by anatomical structures that we have since found to be unreliable. This suggests that the dead grass carp was probably in fact older and originated from the legal stockings. The use of multiple biological measurements on a modest sample size of grass carp, combined with the knowledge that no juvenile grass carp have been observed since legal stocking occurred, lead us to conclude that the grass carp in Devils Lake are sterile fish that originated from legal stocking events. |
| Genre | Article |
| Topic | Asian carp |
| Identifier | Clemens, B. J., Spangler, J. J., Robertson, P. L., Galovich, G. M., Banner, C. R., Gunckel, S. L., ... & Kirk, J. P. (2016). Persistence of Triploid Grass Carp in Devils Lake, Oregon. Journal of Fish and Wildlife Management, 7(1), 153-161. doi:10.3996/042015-JFWM-044 |
