Relative importance of chinook salmon abundance on resident killer whale population growth and viability

Publication Type:Journal Article
Year of Publication:2014
Authors:L. A. Vélez-Espino, Ford, J. K. B., Araujo, H. A., Ellis, G., Parken, C. K., Sharma, R.
Journal:Aquatic Conserv: Mar. Freshw. Ecosyst
Date Published:21 August 2014
Keywords:chinook salmon, demography, elasticity, extinction risk, killer whale, matrix models, perturbation analysis, population viability analysis

1. Two distinct populations of resident killer whales (Orcinus orca) in the north-eastern Pacific Ocean have been listed in Canada and the USA as being of conservation concern. One of the major threats recognized for these two populations is nutritional stress associated with prey abundance levels and availability.
2. The predominance of chinook salmon (Oncorhynchus tshawytscha) in the summer diets of both killer whale populations has been shown by recent studies, and correlations between indices of chinook salmon abundance and resident killer whale (RKW) vital rates have generated hypotheses about the potential for chinook salmon abundance to limit RKW population dynamics.
3. This study merges statistical inference derived from linkages between RKW vital rates (survival probability and fecundity rates) and chinook salmon abundance with demographic perturbation analysis and population viability analysis to address some of the pressing questions that have recently engaged the efforts of scientists and managers interested in: (1) the role of chinook salmon abundance in the population dynamics of RKW; and (2) how RKW population viability is expected to respond to changes in chinook mortality owing to harvest.
4. Numerous interactions between the abundance of chinook salmon aggregates and RKW vital rates were found and deemed to result from predator–prey dynamics. However, the results of this present analysis also indicated that the effects of these interactions on RKW population growth and viability are relatively small and/or uncertain and in need of further research.
5. Other factors (genetic, environmental and/or anthropogenic) could be at play limiting RKW population growth and possibly masking and confounding the detection of stronger interactions between RKW vital rates and chinook salmon abundance. Given the current state of information, it is highly uncertain whether the allocation of chinook salmon resources for RKW would be an effective management action in RKW recovery plans.



This website is a demonstrator for the integration of several informatics technologies useful in "in-silico" biodiversity science: Scratchpads, Taverna Player and BioVeL infrastructure for executing workflows. This particular example makes use of population census data for Killer Whales and abundance data for Chinook Salmon in the north-east Pacific Ocean, which has kindly been provided by Antonio Velez-Espino of Fisheries and Oceans Canada. Please do not rely on the data or results information provided for any actual scientific, conservation or policy use. Mistakes herein (of which there are several) are solely the responsibility of the technical parties working on the technology integration. These include: Cardiff University, University of Manchester and the Natural History Museum, London.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith