Keeping Pace With Climate Change?


Copepods are among the most important organisms in the ocean.

Copepods are among the most important organisms in the ocean. The millimeter-small animals are food for many fish species and are therefore of central importance for life in the sea. Marine biologists fear that climate change could affect the small crustaceans in the future – and that this could decimate the most important food source for fish and many other marine animals. A team from GEOMAR Helmholtz Centre for Ocean Research Kiel, the University of Connecticut, and the University of Vermont has therefore investigated for the first time in more detail whether copepods can genetically adapt to changing living conditions over the course of evolution. In doing so, they have taken into account both the effect of higher water temperatures and ocean acidification. The work of the U.S.-German group is special because it was one of the first to expose marine animals to multiple stressors in the lab.

The results, recently published in the scientific journal Proceedings of the National Academy of Sciences, are cautiously optimistic. The team, led by Professor Dr. Reid Brennan, marine ecologist at GEOMAR, and Professor Dr. Melissa Pespeni of the University of Vermont, found through detailed genetic analysis that the small crustaceans can indeed adapt to the new conditions over the course of about 25 generations – which corresponds to a period of just over one year, since several generations of crustaceans can mature in a year at moderate water temperatures. The researchers found that as water temperatures rise and conditions become more acidic, gene variants become prevalent in the copepods’ genome that result in the animals being better able to withstand environmental stress. "These mechanisms help, among other things, to ensure that copepod eggs develop properly despite unfavorable environmental conditions and that important metabolic processes continue," says Reid Brennan.

Read More at: Helmholtz Centre for Ocean Research Kiel