Jonathan Dombrosky, a Ph.D candidate and Associate Professor Emily Lena Jones, both from the Department of Anthropology at The University of New Mexico, recently received a National Science Foundation grant for $30,298 to research the impact of a changing environment on the incorporation of new foods into human diets. 

“My dissertation research centers on one broad question: How and why do people who heavily rely on agriculture make decisions about new foods to eat? I specifically focus on fishing here around Albuquerque about 700 to 400 years ago among Ancestral Pueblo farmers. I am particularly interested in how people might have responded to environmental change – wetter conditions in this instance – to include more fish in their diets,” said Dombrosky.

This project helps develop archaeologically visible indicators of when a food type recovered in relatively low abundance might relate to human nutritional demands. In the American Southwest, it has long been assumed that fishes were unimportant in the diet of Ancestral Pueblo groups, he noted. Yet, small numbers of fish remains are consistently recovered from late prehispanic archaeological sites in New Mexico, and they are rare during earlier time periods. 

“This is a tricky question. Fishing certainly wasn’t the main way that people were getting enough food to eat back then. They were, after all, farmers, but I think Ancestral Pueblo people fished more than most archaeologists think they did to supplement their diets. So, the idea that fishes don’t matter at all among Pueblo groups (which has been a major assumption for a long time) is categorically false,” Dombrosky observed.

The end of drought conditions may have impacted how people made different decisions about the foods they ate, Dombrosky said. In addition, prehispanic fishing in desert ecosystems is of interest to both archaeologists and ecologists. 

According to Dombrosky and Jones, understanding more about the ecology of prehispanic fish communities will provide a new source of paleoenvironmental information in a region where fish remains are thought to be insignificant. Desert streams are of critical conservation concern given modern anthropogenic impacts and current drought forecasts. The results of this project will be of interest not only to scholars, but to agencies charged with the management of plants and animals in desert ecosystems. 

“There are a few reasons why this research matters for today. First, this research provides a case study in how people alter their diets to changing environmental conditions (especially people who rely on agricultural food production). How people make choices about different foods to eat, in the face of a changing environment, is important to understand in different places and in different times to make better decisions about our diets in the future,” Dombrosky said.

“Second, a large part of this project is about better understanding the ecology of fishes and of the Rio Grande ecosystem itself before Euro-American contact. Conservation biologists don’t have a very good idea what food webs were like or how they functioned back then. So, this research provides them with baseline information about what the Rio Grande was like and how much it has changed. 

“Finally, the public, government, ecologists, and biologists are worried about the environmental impact of fisheries. An important question is: How can we constantly and sustainably use fisheries? This research about prehispanic desert fisheries here in New Mexico turns this issue on its head a little bit because Ancestral Pueblo people seem to have engaged only slightly with the Rio Grande fishery. This underscores some important potential questions about fishery management: when Ancestral Pueblo people did engage with the fishery what triggered them to do so? What lessons can we learn from people who did not rely on fisheries much (but still did use them) to reduce our impact on coastal and freshwater environments?

Dombrosky, under Jones’ supervision, is using theory rooted in behavioral ecology to understand how fishing might have become an optimal food-getting strategy for Ancestral Pueblo farmers. Three lines of evidence will test this question: radiocarbon dates of fish bones, to establish the timing and tempo of fishing; body size estimations of fishes from archaeological sites, to assess whether they were unusually large; and analysis of the stable isotopic composition of fish bones recovered from these sites, to determine if fishes had more variable diets during the late prehispanic period.  

“I’m really excited about this project, and one thing that I’m particularly happy about is that I get to provide a job for one undergraduate student here at UNM. I’m excited to help provide this opportunity because it can sometimes feel exceptionally difficult to get your foot in the door in this field of research. It’s nice to provide that chance for someone while also providing financial support.”