Jackson Estuarine Laboratory


Ecological studies of economic red algae. v. growth and reproduction of natural and harvested populations of Chondrus crispus Stackhouse in New Hampshire


The seasonal growth, reproduction, and occurrence of Chondrus crispus Stackhouse have been determined at four New Hampshire locations and correlated with seasonal and spatial variations of surface salinity, temperature, and nutrients. Spring growth was initiated in March and April. Chondrus populations exhibited their maximum size and biomass during the late summer-fall. The period of fastest growth coincided with increasing summer temperature and day-length. Seasonal and spatial differences of reproduction were noted at the four sites. Cystocarpic plants were usually abundant during the late summer-winter. Tetrasporic plants showed a sporadic occurrence and were less common than cystocarpic plants — particularly at the more sheltered sites. The most extensive populations of Chondrus occur on the open coast i.e., on massive outcrops and boulders in the mid subtidal zone (−3 to −5 m below M.L.W.).

The re-growth and reproduction of Chondrus populations after harvesting is dependent on the time and initial level of harvesting. Carefully and moderately harvested plots of the summer allowed re-growth to control levels of biomass in 5 to 6 months; the same quadrats were at or near (80 %) of the control values of reproduction after 9 months. Winter harvests had a more prolonged effect on re-growth and reproduction. Intertidal quadrats that were sequentially denuded for 22 months showed a biomass equal to the controls after 18 months of re-growth; reproductive structures were found after 13 or more months of re-growth.

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Journal Title

Journal of Experimental Marine Biology and Ecology

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Copyright © 1975 Published by Elsevier B.V.