Deep-sea corals reflect Pacific Ocean shift

Long-lived deep-sea corals preserve evidence of a major shift in the Pacific Ocean ecosystem since 1850.

The tree-like skeletons of deep-sea corals are able to record long term changes in their environment through a composition of hard protein material that incorporates chemical signatures from their food sources.

Any changes in this composition reflect changes in the organisms that lived in the surface waters at the time each layer formed.

Study of these corals indicates that changes at the base of the marine food web observed in recent decades in the North Pacific Subtropical Gyre may have begun more than 150 years ago at the end of the Little Ice Age.