200,000th Collector Sea Urchin Planted to Protect Kaneohe Bay Native Hawaiian Species Protects Coral Reefs from Invasive Seaweeds

Another milestone was reached today, as teams from the Anuenue Fisheries Research Center (AFRC), a facility of the state’s Division of Aquatic Resources (DAR), planted the 200,000th juvenile sea urchin in Oahu’s Kaneohe Bay. Over the past three years, AFRC has successfully spawned and raised collector urchins in captivity with the express purpose of releasing them in the bay as part of an ecosystem-based management plan and for environmental mitigation work.

The combination of fast-growing seaweeds that smother patch reefs and the depletion of native sea urchin populations were rapidly altering the natural ecosystem balance in Kaneohe Bay.  “Now with our two-pronged approach; utilizing the ocean-going vacuum Super Sucker to remove seaweed from affected coral reefs, combined with the introduction of the native Hawaiian collector urchins (Tripneustes gratilla), we’re beginning to see the bay return to a more natural condition,”said David Cohen, DAR sea urchin hatchery manager.

The urchins act as underwater gardeners and help keep invasive seaweeds under control. This allows corals to grow and provide habitat for juvenile reef fish and other aquatic creatures like squid and octopus.

“The propagation and release of 200,000 urchins is a remarkable accomplishment,”said William J. Aila, Jr., chairperson of the Department of Land and Natural Resources (DLNR). “The DAR hatchery team is the first to raise sea urchins in captivity for this purpose and while others in Hawaii have raised urchins in smaller laboratory environments, none have been successful on a large scale.”

The Kaneohe community and volunteer groups have been instrumental in supporting this program. Other partners include groups from the University of Hawaii, The Nature Conservancy, the National Oceanic and Atmospheric Administration (NOAA) and numerous non-profits.

The community has a chance to learn more about the urchin program during “Urchins-The Underwater Gardeners of Kaneohe Bay” day at Windward Mall in Kaneohe. This outreach event will be held at center court on Saturday, March 29, from 10 a.m. – 2 p.m. In addition to being able to see juvenile urchins up close, there will be interactive games for keiki and a chance to talk story with the team from the Anuenue sea urchin hatchery team.

View the original press release at:  dlnr.hawaii.gov/blog/2014/03/28/nr14-039