Hearing the Reef with our "EARs"

A Better Understanding of Coral Reef Ecosystems

Pelagic predators such as these barracuda, Sphyraena qenie, are part of the coral reef ecosystem in the U.S. Line Islands (NOAA Photo by Kevin Lino).

A team of scientists have embarked from Hawai'i on a three-month survey of coral reef ecosystems at Johnston Atoll, the U.S. Phoenix Islands, the islands of American Samoa, and the U.S. Line Islands in the tropical Pacific Ocean. The overarching objective is to better understand the coral reef ecosystems of these areas, many of which are seldom explored. The research expedition is part of a regular monitoring program, conducted by the Coral Reef Ecosystem Division (CRED), headquartered in Honolulu, Hawai'i. The expedition is supported by NOAA's Coral Reef Conservation Program and involves extensive cooperation among NOAA scientists and research partners, including the University of Hawaii Joint Institute for Marine and Atmospheric Research (JIMAR), the U.S. Fish and Wildlife Service, San Diego State University, and the Papahānaumaokuākea Marine National Monument.

The research expedition will be carried out from February 27 to May 24, 2012 aboard the NOAA ship Hi'ialakai. Under the leadership of Chief Scientists Dr. Jill Zamzow, Dr. Bernardo Vargas-Angél, and Jamison Gove, a diverse team of researchers will be conducting multidisciplinary coral reef ecosystem surveys, assessing the status of fishes, corals, algae, marine invertebrates, and the oceanographic conditions in which these organisms exist. The scientific data collected during the three-month research expedition will enable informed and effective implementation of ecosystem-based management and conservation strategies for coral reef ecosystems, helping to ensure their protection for generations to come.

Sunday, April 26, 2009

Hearing the Reef with our "EARs"

Scientists deploy an EAR on a nearby reef

Recently we have had several questions about the EARs or "Ecological Acoustic Recorders" we are deploying at various islands and reef to monitor sounds in the shallow water areas during the year or two between expeditions.

Mr. Hill's period 2 class asks: "What type of fish can you hear with the EAR or what was the most exciting thing you have heard on the EAR?"

The Ecological Acoustic Recorder can record a variety of sounds. We often listen to whales, dolphins, snapping shrimp and of course fish. Some of the most common fish sounds that we have identified are the domino damsel fish Dascyllus albisella (a purr), the soldierfish Myrispristis sp. (drum sound) and the butterfly fish Chaetodon sp. Many of the fish sounds we listen to have not yet been linked to a particular species and we are collaborating with the University of Hawaii and Dr. Tim Tricas to identify fish and sounds they produce.

One of the most exciting findings the EARs have provided is the discovery of Humpback whales using the Northwestern Hawaiian Islands (NWHI) as a winter habitat, just as they do in the main Hawaiian Islands. It was commonly thought that Humpbacks only transited through the NWHI. EARs in the NWHI have recorded Humpback whale song, indicating the use of the area as a breeding site.

We have had an occasion where some unknown sounds on one of our EARs puzzled us for a couple of days. We would only hear snippets of what sounded like human voice. But the dates of occurrence of these sounds did not correspond with our deployment or retrieval of the device, so it could have not been from our divers, not to mention the fact that humans cannot usually make comprehensible sound underwater. In the end, it turned out to be a filming crew who was getting underwater footage and we suppose they had underwater speakers. The first full recording that we got of it said "ACTION, Action ... Follow the diver to the left..."

Who knows what we will hear next ...

A deployed EAR listens and waits ...

1 comment:

Angelo VillagomezApril 28, 2009 at 2:04 PM
The next time you guys swing by Saipan I hope we can set up some (or one) education and outreach activitie(s) with local schools.
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