Protecting Ocean Ecosystems

A Shallow Question on Deep Corals

A high diversity coral community living together on a hard rock area. Image courtesy of NOAA Okeanos Explorer Program, Our Deepwater Backyard: Exploring Atlantic Canyons and Seamounts.

In October Talking Fish carried a post about deep-sea corals from The Pew Charitable Trusts. A Pew staffer shared his experiences aboard the Okeanos Explorer, one of the vessels used by the National Oceanic and Atmospheric Administration to explore the deep seas, and mentioned that fishery managers in the mid-Atlantic are considering a proposal to protect some deep corals from potential harm from fishing gear.

The post prompted this question from Greg DiDomenico, Executive Director of the Garden State Seafood Association in Trenton, New Jersey.

“What evidence do you … have that bottom trawls are having an impact in Mid Atlantic Ocean Canyons? Did Aaron [the Pew staffer] see evidence of bottom trawling when he was aboard the Okeanos?”

The one-day expedition featured in the October post did not find any damage to deep corals. That’s not surprising, given that the submersible dive was deeper than 500 meters and in a remote section of sea canyon.

But other expeditions in the region and throughout the Atlantic Coast provide ample evidence of the damage that bottom trawling and other fishing gear can do.

For example, a 2012 expedition into Baltimore Canyon found abandoned fishing gear such as traps, lines, and nets on nearly every dive.

NOAA Ocean Explorer: NOAA Ship Okeanos Explorer: Northeast U.S.

Abandoned nets

Abandoned commercial fishing trap

Abandoned longline gear, nets, and commercial fishing trap. Images courtesy NOAA Okeanos Explorer Program, 2013 Northeast U.S. Canyons Expedition and Deepwater Canyons 2012 Expedition, NOAA-OER/BOEM.]

Work by renowned deep corals experts Peter Auster and Les Watling have also revealed numerous examples of damage from fishing gear. In a report this year to the New England Fishery Management Council, Auster and other scientists wrote about “areas exhibiting recent direct impacts from fishing activities” in at least three areas in the Gulf of Maine. “The peaks of some ridges and nearly horizontal sections of wider outcrops were also denuded. Tracks observed here were consistent with impacts from mobile fishing gear,” they wrote.

trawl tracks

Trawl tracks and coral damage. : Images from “Imaging Surveys of Select Areas in the Northern Gulf of Maine for Deep-sea Corals and Sponges during 2013-2014. Report to the New England Fishery Management Council - 30 October 2014.”

Trawl tracks and coral damage. Images from “Imaging Surveys of Select Areas in the Northern Gulf of Maine for Deep-sea Corals and Sponges during 2013-2014. Report to the New England Fishery Management Council – 30 October 2014.”

Watling has also recorded other incidents of extreme damage. In an opinion piece last year in the New York Times, Watling wrote of centuries-old corals “smashed by trawl gear. Bottom images of trawled deep-sea areas, and two seamounts I visited with a deep-diving remote vehicle, show that nothing is left standing in the wake of this type of fishing gear.”

Watling also used his piece in the Times to make a key point about conservation: you can’t protect what is already lost. As fisheries in shallow waters are depleted around the world, the fishing industry has moved to deeper waters. The magnificent corals NOAA’s explorations are revealing in our waters should be protected before such an expansion causes irreparable harm.


3 Responses to A Shallow Question on Deep Corals

  • Richard Nelson says:

    I think it’s in really poor taste to even infer that Mr. DiDemenico’s question was shallow. Why wouldn’t one in his position want proof before he’s lead off the deep end. Kind of a built in adversarial assumption going on here, But then I’ve mentioned that before.

  • Bob Vanasse says:

    I presume whoever wrote this headline thought it was cute, but there is no reason to be insulting when making a point. As the expression goes, it’s possible to disagree without being disagreeable.

    Greg’s question was obviously not “shallow” since your answer is that none were seen. Your additional evidence is interesting and worthy of consideration, but that doesn’t make Greg’s question out of line or “shallow.”

    The headline does however make CLF look smug.

  • Ron Huber says:

    One well documented encounter between primnoan corals and a Canadian trawler doing a trawl survey in the canyon between Georges Bank and Browns Bank – even though it was a coral conservation area. See photos of the result at

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