Background
Capelin (Mallotus villosus) are small short-lived forage fish that are the primary prey of many top predators in northern marine ecosystems. They typically spawn in one of two specific habitats with divergent temperature regimes: beach (warm, variable) and deep water (demersal: cool, stable). And in recent years there has been some concern about how capelin may or may not respond to projected global warming and what the consequences of those actions might be.

What was done
In both 2009 and 2010, Davoren, as she describes it, "investigated the influence of temperature on spawning habitat selection in coastal Newfoundland by quantifying habitat-specific temperature, population-level habitat use, and individual-level movements of male capelin via acoustic telemetry."

What was learned
The Canadian researcher reports that "capelin spawned only at beaches in 2009, when temperatures were significantly colder and frequently fell below suitable ranges at demersal sites, whereas demersal sites were predominantly used under opposing conditions in 2010." And she remarks that "males detected in both habitats primarily dispersed from the initial habitat when temperatures routinely fell outside of suitable ranges," noting that "this movement often involved traveling long distances (11.0-32.7 km) against currents, suggesting energetic costs."

What it means
"Overall, temperature appeared to be an important environmental cue for habitat selection by capelin," in the words of Davoren; and she thus concludes that "the flexible use of spawning habitats under divergent temperature conditions suggests that capelin have a high capacity to respond to and possibly tolerate predicted ocean-climate change."