Fossil Record Reveals Crustaceans Decline with Coral Reefs

Coral reefs are continuing to decline across the globe as the climate shifts and changes. Now, scientists have found that it's not just corals in trouble. By looking at the fossil record, researchers have discovered that many ancient crustaceans went extinct following a massive collapse of reefs across the planet.

In order to examine how the decline of coral reefs might have impacted species in the past, the researchers created a database of fossils from the Mesozoic Era, 252 million to 6 million years ago. The data included 110 families, 378 genera and 1,298 species. The researchers analyzed the patterns of diversity and found that the number of decapod species was influenced by the abundance of reefs.

"We estimate that Earth's decapod crustacean species biodiversity plummeted by more than 50 percent during a sharp decline of reefs nearly 150 million years ago, which was marked by the extinction of 80 percent of crabs," said Adiel Klompmaker, one of the researchers, in a news release. "If reefs continue to decline at the current rate during this century, then a few thousand species of decapods are in real danger. They may adapt to a new environment without reefs, migrate to entirely new environments or, more likely, go extinct."

Climate change is severely impacting today's reefs. Warmer temperatures are causing corals to bleach, which can kill off entire swathes of the reef. Needless to say, this loss of habitat can also affect other species. And some researchers predict as much as 20 percent of the world's reefs may collapse within 40 years.

"This new work builds a good case for the role of reefs in promoting the evolutionary diversification of crustaceans," said David Jablonski, a paleontologist in the department of geophysical sciences at the University of Chicago who was not involved in the study, in a news release. "We have to take their argument for the flipside of that story very seriously. The positive relation between reefs and crustaceans implies that the damage caused to reefs by human activities--from overfishing to ocean acidification--is likely to have cascading consequences for associated groups, including crustaceans."

The findings are important for understanding exactly how crustaceans might be impacted in the future. As coral reefs decline, other species can be affected. The fact that this has happened in the past lends further weight to the seriousness of coral reef decline in the face of climate change.

The findings are published in the journal Geology.