He earned a Ph.D. in ecology at University of California-Davis in 1990 working with the limnologist Charles R. Goldman, producing a dissertation titled "Nutrients, algae, and grazers: complex interactions in lake ecosystems".

[3] In 2016 he moved to University of Montana, where he directs the Flathead Lake Biological Station,[4] while remaining a research professor at Arizona State.

Particular contributions include global analyses of the nutrient limitation of primary producers,[6] the stoichiometry of nutrient recycling,[7] and the linkage between the phosphorus and RNA content of organisms and their growth rate (the Growth Rate Hypothesis).

[8] This work is summarized in the 2002 book Ecological Stoichiometry,[9] co-authored with Robert Sterner.

Elser has also organized Woodstoich, a series of four workshops on ecological stoichiometry for early career researchers.