Marine life may adapt to climate change, but at a hidden cost

Suppose we could observe 20 generations of whales or sharks adapting to climate change -- measuring how they evolved and how their biological structures changed as temperatures and carbon dioxide levels rose

Instead, consider the life of the copepod Arcadia tonsa, a tiny and humble sea creature that sits at the bottom of the food web

A team of six scientists led by University of Vermont biologist Melissa Pespenny and postdoctoral scientist Reed Brennan did just that: In a first-ever laboratory experiment, they fed thousands of copepods Exposure to high temperatures and high carbon dioxide levels is what predicts the future of the ocean

The findings, published in the journal Nature Communications, "show promise," Pespeni said, "but also show the complexity of how life responds to climate change

The cost of plasticity

Her hope comes from the team's observation that copepods are not dying under climate change conditions

This complexity -- "it's really a warning," Pespeni said -- came from the team's observations of copepods that returned to a baseline state

"If copepods or other organisms had to go down this adaptation path, with some genetic variation to respond to climate change, would they be able to tolerate some new environmental stress, other changes in the environment?" Pespeni wonders

"But we need to be careful about overly simplistic model species that will and which will persist into the future, and look at just one variable," said Reid, of Brennan, who completed the research in Melissa Pespeni's lab at the University of Vermont, which is now GEOMAR Helmholtz Center for Oceanographic Research in Kiel, Germany