Archive of Spotlight Feature Articles

UNH Researchers Working to Revitalize Gulf of Maine Urchin Industry

Christine Fagan, NH Sea Grant

During the past 10 years, the Gulf of Maine green sea urchin industry has gone from boom to bust. University of New Hampshire researchers are working to bring it back.

After being ignored by New England commercial fisherman for hundreds of years, the prickly urchins started getting noticed in the early 1980s. They migrated en masse through Northeastern waters, gorging themselves on kelp beds and leaving the bottom of the ocean barren. The effects were disastrous for lobsters because the crustaceans thrive in dense kelp.

Larry Harris, UNH professor of zoology, has been studying marine communities for 30 years. He explained that after the urchins took over commercial fishermen began taking advantage of the opportunity to tap into the large Japanese market for sea urchin gonads. Known as uni, the gonads are considered a delicacy. During the late '80s this new fishery was a gold rush.

By 1993 the resource had peaked and urchin populations began to decline. Harris, who had started monitoring the recruitment of young urchins in 1983, found last year's recruitment to have reached an all-time low.

Harris is now being funded by NH Sea Grant and the UNH Agricultural Experiment Station to find the most efficient way to grow large numbers of sea urchins in hatcheries. This type of production may be the only way the Gulf of Maine will have any long-term role in the sea urchin market. He is experimenting with different types of growing containers, including rafts and panels. Urchins are cultured until they reach a suitable size, then outplanted or released into the ocean because storing them is expensive and labor intensive. Cultured urchins can be used to replenish wild stocks or in aquaculture efforts on leased sections of the ocean bottom.

(Left) UNH zoologist Larry Harris has been studying green sea urchins in the Gulf of Maine for 30 years. (Right) Over the years, dozens of UNH students have gotten an introduction to hands-on science through an involvement in sea urchin research, including this student who made sure the urchins were getting a summer photoperiod even during the dark days of winter.

During the past academic year, Harris served as advisor for a Tech 797 project in which students developed an urchin growth system. Tech 797 is a year-long course that allows interdisciplinary teams of undergraduates to collaboratively address marine issues. The students involved, Laura Marshall, Seung Suk and Brian Sullivan, members of the class of 2000, won the David Drew Memorial Award for their efforts. The award is given annually to the year's best project.

Harris said that the growth system showed great promise and that another project team is developing it further this semester. He hopes UNH will have an active sea urchin aquaculture hatchery in operation by early 2002. Currently there is only one hatchery in operation in the region. Located in Lubec, Maine, and operated by Peacock Canning Co., it is a side effort in a salmon hatchery.

Natural settlement of urchins occurs in June and July in the Gulf of Maine, and this is also when outplanting might be expected to take place. The problem Harris encountered with this is that it is also the time when the urchins' predators, crabs and certain fish, are most active. The alternate plan is to outplant urchins in the winter when urchin predators are inactive. Initial results suggest that winter outplanting is effective and further trials are planned.

Researchers Charles Walker, UNH professor of zoology, and Michael Lesser, UNH associate professor of zoology, are also addressing a different approach for helping the urchin industry, with funding from Sea Grant, the UNH Agricultural Experiment Station and the Department of Commerce.

Light plays an important role in the sea urchin reproductive cycle, and by manipulating photoperiod (daily exposure to light), Walker and Lesser have been able to induce reproduction at different times during the year. By manipulating their reproductive cycle and using specialized feed Walker and Lesser can supply high quality gonads, targeting specific times such as holidays.

Walker and Lesser have been using their knowledge of the urchin reproductive system to develop land-based techniques to be used in the industry for producing optimal uni. While Japan is the largest market for uni, there are smaller markets in France, Belgium, Greece, Italy and Turkey. The ideal gonad is classified by its large size, firmness, color, texture and taste. Gonads are only marketable during a specific phase of the reproductive cycle, so by manipulating photoperiod it is possible to have ideal gonads available continuously. Additionally, having reproductively mature urchins at different times of the year could assist biomedical research because urchins are an important model organism for the study of embryo development.

Michael Devin is an aquaculturist at the University of Maine's Darling Marine Center. Devin sells sea urchins to the Japanese market and has implemented some of Walker and Lessers' findings. Walker hopes to help others like Devin and is currently building a web site to make his results more accessible to the public.

[3/12/01]

CLIMATE · OCEANS, GREAT LAKES, and COASTS · WEATHER and AIR QUALITY
ABOUT US · RESEARCH PROGRAMS · EDUCATION · HOME

Contact Us
Privacy Policy