Invasive fishes frequently change natural aquatic habitats due to predation and competition. The Alaska blackfish (Dallia pectoralis) is indigenous to some regions of Alaska but was illegally introduced to the Cook Inlet Basin in the 1950s. By the 1970s, fisheries managers expressed concern over possible ecosystem-altering effects of the blackfish introduction, especially in waterbodies containing popular sport fish. Descriptive food habit studies may assist fisheries managers in making decisions regarding management of non-native populations of Alaska blackfish. This project characterizes diet of three Cook Inlet Basin Alaska blackfish populations through stomach contents analysis. Shifts in diet across season, sex, and size of individuals from a lake, wetland pond, and stream are discussed using the Index of Relative Importance. Cook Inlet Basin Alaska blackfish consume similar invertebrate prey as native juvenile salmonids and stickleback, with major prey consisting of epiphytic/benthic dipteran larvae, gastropods, and ostracods. Piscivory, including cannibalism, is infrequent in these populations. Due to the high degree of dietary overlap with native fishes and stocked sport fish, and evidence that many Cook Inlet Basin waterbodies contain established populations of Alaska blackfish, fisheries managers should take actions to restrict the spread of blackfish through public awareness education, law enforcement, and funding for additional research. An Alaska blackfish husbandry manual outlines closed-system rearing and artificial fertilization protocols useful to researchers and educators for keeping live Alaska blackfish in the laboratory and classroom, in order to add to our body of knowledge about this species.
|Advisor:||von Hippel, Frank A., Lopez, J. Andres|
|Commitee:||Carlson, Matthew L., Lassuy, Dennis R.|
|School:||University of Alaska Anchorage|
|School Location:||United States -- Alaska|
|Source:||MAI 54/04M(E), Masters Abstracts International|
|Subjects:||Ecology, Aquatic sciences|
|Keywords:||Biological invasion, Competition, Index of relative importance, Piscivory, Predation, Stomach contents analysis|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be