How does stocking density affect enhancement success for hatchery-reared red king crab?

• Main Authors: Long, W. Christopher, Cummiskey, Peter A, Munk, J. Eric
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: NRC Research Press (a division of Canadian Science Publishing) 2018
• Subjects: Kodiak; Red king crab; Alaska
• Online Access: http://hdl.handle.net/1807/90287; http://www.nrcresearchpress.com/doi/abs/10.1139/cjfas-2017-0330

Stock enhancement of red king crab could increase the crab population near Kodiak, Alaska, which collapsed in the 1980s and has not recovered. We conducted a field experiment examining the effect of juvenile red king crab density on enhancement success. Hatchery-reared crabs were released in plots near Kodiak at three densities: 25, 50, and 75 m-2. Crab densities were monitored for 6 months after release. Predation risk was measured via tethering experiments and predator density via quadrat and transect surveys. Neither migration nor mortality changed with crab density, but mortality rates decreased over time. Crab density did not affect predator density or predation risk, although predation risk decreased with time. Excluding the high initial mortality rate of 67.5%, predicted survival after 6 months was 34%, which is better than the survival observed in a wild population. This suggests that red king crab enhancement is not predation-limited and can occur at high densities. Further, processes affecting juvenile red king crab may not be strongly density-dependent at least at the scales and habitats tested. The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author.