From ScienceDaily: 

Tiny crustaceans called copepods rule the world, at least when it comes to oceans and estuaries. The most numerous multi-cellular organisms in the seas, copepods are an important link between phytoplankton and fish in marine food webs.

To understand and predict how copepods respond to environmental change, scientists need to know not only how many new copepods are born, but how many are dying, say biological oceanographers David Elliott of the University of Maryland Center for Environmental Science and the Virginia Institute of Marine Science (VIMS), and Kam Tang of VIMS.

Elliott and Tang realized there was only one way to discover the answer: find the copepods’ carcasses. Read more.