2015 Summer Internship Program
Offshore Food Availability and Diet Composition of Subyearling Chinook Salmon in Puget Sound
My name is Haila Schultz, and I am pursuing a biology major and English minor at the University of Puget Sound in Tacoma, Washington. I grew up in Southeast Alaska, where my passion for marine and fisheries biology took seed and developed. This summer I had the wonderful opportunity to work in the lab of David Beauchamp at the University of Washington School of Aquatic and Fisheries Sciences as a JISAO intern. My project compared the stomach contents of juvenile Chinook salmon in Puget Sound to the food availability in their environment.
Chinook salmon are listed under the United States Endangered Species Act, and their populations are declining. Recent research shows a strong relationship between the size of a fish by its first July in the offshore environment and marine survival. Therefore, the growth that occurs within the first months that Chinook spend in the marine environment is important to overall survival. The Beauchamp lab studies the factors affecting growth during this critical time. One of these factors may be the availability of high-quality prey in the environment. Prey availability may also be affected by prey selection and utilization. While juvenile Chinook eat a diverse range of insects and zooplankton, larval crab is known to be an important diet item. Understanding the effect of prey availability on Chinook survival is important for understanding population dynamics and for informing conservation efforts.
This summer I worked with Chinook diet contents and zooplankton tow data collected in the offshore environment of two watersheds in the spring and summer of 2014. I also had the opportunity to go into the field and help collect samples on one of the purse seining research cruises. In the lab, I processed diet samples by measuring the wet weight of different prey items found within each sample. I examined the diet compositions of fish caught in the two watersheds and compared the proportions of larval crab in the diets to densities of larval crab in the water column. Larval crab was, indeed, an important prey source. Additionally, the peak densities of ambient larval crab in the Southern watershed occurred before many subyearling Chinook had arrived in the offshore environment. If the density of larval crab in the offshore environment is limiting for Chinook, it may affect marine survival.
My experience as a JISAO intern has been extremely valuable and enjoyable. I was able to be a part of a large, hard-working, collaborative lab group consisting of interns, undergraduates, lab technicians, and graduate students. In learning about other projects in and around the Beauchamp lab, I caught a glimpse of the breadth of research possibilities within the field of fisheries science. As a result, I have gained a much more thorough understanding of what graduate work entails, and I have grown as a researcher. I had an amazing summer thanks to the JISAO staff, my mentors, and all of the students and staff who helped me with my project.
Click image for full size PDF