Exploring cold Alaskan rivers, wild salmon and a passion for aquatic entomology
I remember when I first splashed into a river in my waders. The water was cold and supported my legs, the water pressure felt comforting. At the same time, I felt scared that the formidable current would dislodge my footing on the unsecure rocky bottom. Once I got comfortable, I began observing aquatic insects in these streams; I became captivated, hooked, an instant passion that I am certain will fascinate me for the rest of my life. Insects are the most diverse group in the animal kingdom, with an estimated 20-30 million species. It is incredible that insects have evolved the ability to live in exceptionally diverse habitats, from the ephydrid flies living in the high salinity Great Salt Lake, the anoxic habitats in streams where chironomid flies have developed hemoglobin molecules in their hemolymph (insect blood), and other chironomid flies that can withstand complete dehydration in Nigeria, Africa. I began to look into the water I was standing in and my interest became focused on aquatic insects. It is astonishing that insects have evolved to survive in the dynamic and challenging aquatic world. My favorite group of aquatic insects are the elusive caddisflies, order Trichoptera. Some families of Trichoptera build cases, which vary greatly, from cases out of snail shells, sand, or woody debris and leaves. These cases are an elegant way to survive and inspired thought about trying to understand other interesting ecological and evolutionary aspects of aquatic ecosystems.
After earning a Bachelor’s degree in Biology at Humboldt State University in northern California, I went to Michigan State University and worked on my master’s degree under the direction of Dr. Richard Merritt, a well-known forensic and aquatic entomologist. My master’s thesis focused on understanding how pink salmon (Oncorhynchus gorbuscha) spawning activities affect benthic macroinvertebrates in streams on Prince of Wales Island in Southeast Alaska. I learned that there are changes in the density, biomass and distribution of aquatic insect communities in the stream channel during a salmon run. Within spawning habitat, adult salmon disturbed and dislodged insects from the benthic sediments into drift during nest construction. In non-spawning habitat like pools, stream margins and the hyporheic zone (the region directly below the benthic sediments), insect communities remained fairly stable and did not appear to be affected by nearby spawning-related activities.
Currently, I am working in Dr. Jason Dunham’s aquatic ecology lab at Oregon State University. Broadly, our lab focuses on understanding fish population dynamics, models that can be used to make more educated predictions about our research questions, the effects of habitat selection on fish fitness, and the evolutionary processes that drive observed ecological patterns. My dissertation work will focus on understanding the effects of spatial and temporal changes in water temperature and food availability on juvenile Coho salmon (Oncorhynchus kisutch) growth and bioenergetics in the Copper River Delta, Alaska. The Copper River Delta is an expansive delta and is the largest contiguous coastal wetland along the Pacific Northwest. It is a system of inter-connected ponds, braided streams, rushing rivers and marshland. Compared to its large size, very little research has been conducted in the delta, particularly in the stream ecosystems.
In recent years, we have formed a cohesive group of distinguished aquatic ecologists from Oregon State University, Michigan State University, University of Notre Dame, Humboldt State University, University of Washington and University of Chicago, Loyola. We are trying to understand diverse aspects about the delta including the primary and secondary production in ponds, questions about salmon ecology, whether or not the functional feeding group classification used in streams can be used in pond systems, and understanding hydrologic and biogeochemical processes. An earthquake in 1964 caused the shore-lined section of the Copper River Delta to uplift and transform saltwater habitat into perched freshwater ponds. We are additionally trying to understand the succession occurring in these newly formed freshwater ponds.
I hope that my current and future research endeavors on the Copper River Delta contribute a greater understanding of: 1) the seasonal variation in juvenile Coho diet and growth efficiency, 2) how changes in water temperature and food quality affect the physiological mechanisms involved in juvenile Coho growth, 3) how juvenile Coho growth rates and efficiencies differ in groundwater and surface-water fed streams, 4) how the potential synchrony of Coho salmon fry emergence and important prey items may be altered by global warming, and 5) mathematical models that will be used to make predictions about potential changes in insect and Coho salmon populations in the future. I feel so fortunate to have the opportunity to work in remote Alaskan watersheds that harvest Pacific salmon populations that are still robust and healthy. Although fish are becoming a new interest of mine, I will always have an inexorable passion for aquatic insects and their wild diversity will forever fascinate me.