Jens Hegg


  
I am a PhD candidate at the University of Idaho in the interdisciplinary Water Resources Programworking with Dr. Brian Kennedy, an Associate Professor in the Fish and Wildlife Sciences Department, studying recent migratory changes of Fall Chinook Salmon in the Snake River of Idaho. 


I am interested in the ecology of animal movement and migration, specifically the trade-offs that animals must balance to optimize their ultimate fitness within an environment of complex and changing biotic and abiotic conditions. Within this framework of life history and migration theory I use isotopic tracers, bio-energetic modeling, growth trajectories and geospatial techniques to understand selective pressures affecting life-history changes in populations across space. 

This video is a good introduction to me and the basics of my work. 



As well as ecology I have many interests, coming to academia on a circuitous path, starting with a B.A. in Biology from Macalester College in 2000. In the intervening years I worked in the field studying endangered river mussels in the Hornbach Lab, the distribution of non-game fish with the Minnesota Pollution Control Agency among others. I also spent significant time working in research and development laboratories; in renewable bio-plastics with Natureworks LLC, and designing new coronary stents with Boston Scientific which lead to 4 US patents. My blog mixes my scientific pursuits, musical hobbies and other parts of my life in academia. 



I maintain active research in multiple areas:

Fall Chinook salmon in the Snake River of Idaho 
The juvenile migration strategy of Snake River Fall Chinook salmon has changed in response to dams, with associated changes in flow and temperature creating spatially diverse migration strategies which appear to be adaptive. I use the unique 'tree-ring' structure of fish ear bones (called otoliths) to reconstruct their freshwater migration based upon the unique isotopes in each stream within their range. Using this otolith microchemistry and microstructure I am reconstructing the movements and growth of juvenile fish over multiple years to determine the environmental drivers of migration. The first publication of my Fall Chinook work was published in Oecologia. 
Giant migratory catfish in the Amazon basin of Brazil
Amazonian catfish are known to have the longest migration of any freshwater fsh, from the Amazon estuary to the Andes foothills, yet little is known about their life-history. My research, recently published in PLOS ONE, has shown the details of individual migrations for the first time using isotopic reconstruction of movement from otoliths. These results indicate that juvenile migration tactics are diverse and that multiple migration tactics may be contributing to the population, with the contribution amounts unknown. With documented overfishing and ongoing construction of dams in the Amazon headwaters which may block catfish migration, understanding their migratory ecology is crucial to their future conservation.
Geologic prediction of strontium isoscapes
Strontium isotopes have become a powerful tool to understand migration and movement in ecology. Unlike other isotope systems strontium is useful at multiple different scales, with useful variation both at the local level and at the regional scale.Because strontium isotopes in rivers are tightly tied to the geology of their upstream watershed, it is possible to use geologic maps to predict their variation across the landscape, as I did in a recent Chemical Geology paper. I continue to explore this research, focussing on understanding how scale and geologic heterogeneity affect strontium isotope variation and determining ways to quantify these patterns. 
Data sonification and virtualization for data exploration, artistic expression and scientific outreach
As an interdisciplinary component of my dissertation I have initiated a collaboration with Dr. Jonathan Middleton and Ben Luca Robertson to explore ways of mapping data to sound. The intention of this collaboration is to utilize data-sonification to better undertand complex time series data in otolith research while also exploring the artistic and outreach possibilities of these techniques. This research was recently accepted into the Proceedings of the 12th Annual Sound and Music Computing Conference in Maynooth, Ireland. We have also begun collaboration with a computer virtualization group at University of Idaho and will be working to incorporate our data sonifications into a larger virtual world of salmon migration. 

Recent Publications


Hegg, J. C., Giarrizzo, T., Kennedy, B. P. (2015). Diverse Early Life-History Strategies in Migratory Amazonian Catfish: Implications for Conservation and Management. Plos One, 10(7). doi:10.1371/journal.pone.0129697

Hegg, J. C., Kennedy, B. P., Chittaro, P. M., Zabel, R. W. (2013). Spatial structuring of an evolving life-history strategy under altered environmental conditions. Oecologia, 172(4), 1017–1029. doi:10.1007/s00442-012-2564-9

Hegg, J. C., Kennedy, B. P., Fremier, A. K. (2013). Predicting strontium isotope variation and fish location with bedrock geology: Understanding the effects of geologic heterogeneity. Chemical Geology, 360-361, 89–98. doi:10.1016/j.chemgeo.2013.10.010

(in press) Robertson, B. L., Middleton, J., Hegg, J. (2015). MULTI-CHANNEL SPATIAL SONIFICATION OF CHINOOK SALMON MIGRATION PATTERNS IN THE SNAKE RIVER WATERSHED. Proceedings of the 12th Annual Sound and Music Computing Conference. pre-print on ResearchGate


Curriculum Vitae - view PDF