According to the University of Maine study, urchins can double or triple their roe content to meet market demands during the summer months, a time when wild urchin roe does not normally reach commercially viable size. The results appear in an article in volume 182 of the journal Aquaculture. Co-authors are Robert L. Vadas, Tim Dowling and Jill C. Fegley of the University of Maine Department of Biological Sciences and School of Marine Sciences and Brian Beal of the University of Maine at Machias. Sea urchins are harvested commercially for their roe, or reproductive organs, which are a delicacy in Asia.
Commercial standards require that urchins be at least ten percent roe by weight.
Roe color also helps to determine market prices. In addition to determining the benefits of five different types of natural feed mixtures, the study suggests that diet plays a greater role than previously thought in promoting off-season roe development. Previous studies have suggested that cues regulating growth and development of reproductive cells are largely influenced by length of daylight. Urchins graze on many types of seaweed and can even create barren areas in locations where seaweeds were previously abundant. In such areas, urchin growth and roe enhancement are typically reduced.