Why Oceanography Matters in New Mexico

Clifford Dahm advances water research through interdisciplinary approach.

by Sari Krosinsky

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In land-locked New Mexico, oceanography might seem like a science out of water. But Professor of Biology Clifford Dahm says a multi-faceted approach of oceanography is key to understanding the state’s aquatic ecosystems. “Water is inherently interdisciplinary, whether it’s freshwater or ocean,” he says.

Since coming to the University of New Mexico in 1984, Dahm has used his interdisciplinary background to improve understanding of New Mexico water resources. Dahm presented his work at the Fifty-second Annual Research Lecture, one of the highest honors bestowed on UNM faculty.

Dahm began applying oceanographic tools to non-ocean settings as a graduate student at Oregon State University. It was there that he first observed the significance of the hyporheic zone—the interface between groundwater and surface water in streams and rivers. He noticed that when water goes underground and comes up again, it shows an increase in nutrients and biological activity, an observation confirmed by his later restoration work at the Bluewater Watershed in New Mexico.

Understanding the interaction between groundwater and surface water adds to the picture of how global climate change may affect rivers and streams. Snowmelt rivers, which provide water for about one billion people, or one sixth of the global population, are expected to shrink as rising temperatures decrease snow packs and accelerate evaporation and transpiration. In addition, Dahm’s research suggests that warmer, less viscous fluids move more surface water to groundwater, reducing surface water flows—an effect that becomes more extreme in La Niña years in New Mexico.

Current river restoration in the Southwest tends to be reactive—such as restoring areas damaged by fire or sheltering endangered species—rather than proactively focused on saving water and improving habitat in the long-term. “If you wanted to do an integrated, more holistic restoration, you should look at the whole corridor, and not do it on an ad hoc basis as we do now,” Dahm says. His research suggests that the best place to carry out restoration would be in dense stands of non-native plants where flooding occurs, and there’s a better chance of restoring native plants using natural hydrologic processes.

Dahm, on sabbatical in Australia, is in residence at the Australian Rivers Institute in Brisbane. He is researching the intermittent river and spring systems in the Lake Eyre Basin, which presents aquatic ecosystems similar to New Mexico’s. He also is studying plans to address water shortages and maintain river health in Brisbane, a city of more than two million people already under severe water restrictions—a situation he says New Mexico may be faced with in the not too distant future. “I think we know the condition in which we find ourselves. Whether we are willing to act upon the condition is another question,” he says.

Dahm, internationally recognized for his work in restoration biology, biogeochemistry, microbial ecology, hydrology, climatology, and aquatic ecology, has served as interim director of the Sevilleta Long-Term Ecological Research Program at the Sevilleta National Wildlife Refuge in central New Mexico and is director for the Freshwater Sciences Interdisciplinary Doctoral Program at UNM.