Using what can only be considered a perfect blend of centuries-old mapping technology and modern satellite data, a Colby College professor has presented more proof of shrinking coral reefs in the Florida Keys.

And Loren McClenachan’s fascinating work on the diminishing coral is getting a lot of media attention as Hurricane Irma batters the Caribbean and churns toward Florida.

McClenachan, the Elizabeth and Lee Ainslie Assistant Professor of Environmental Studies, compared 18th-century British nautical charts with current satellite data, and found more evidence of what ocean scientists have been recording: half of the reefs present in the Keys two centuries ago have disappeared.

In a study published this week by the journal Science Advances, McClenachan and colleagues (including Grace O’Connor ’14) describe the work of George Gauld, a surveyor for the British Admiralty in the 1770s. His maps contain the oldest known records of the Florida reefs.

Prof. Loren McClenachan.

Comparing Gauld’s charts (many of them gorgeously detailed with descriptions of wildlife and geology) with present-day satellite images confirmed that the reefs closest to shore are the most diminished.

McClenachan does not provide an hypothesis on why the reefs are disappearing, although warming ocean temperatures and human intervention, including agriculture and waterway engineering, have been implicated in coral death.

Media outlets around the world have published news of McClenahan’s work, including:

IFL Science
Washington Post
Chicago Tribune
The Daily Mail
San Diego Union-Tribune
Atlas Obscura 

The interest is particularly high during this year’s destructive Atlantic hurricane season. As The Washington Post noted, “It’s important to recognize that reefs can protect landlubbers by blunting waves before they can strike the coast.”