Growth and organic production of eelgrass ( Zostera marina L.) in temperate waters of the pacific coast of Japan II. Growth analysis in winter

Abstract

Growth of eelgrass ( Zostera marina L.) in winter in Nabeta Bay, Japan, was investigated in a culture experiment. The mode of vegetative growth was essentially the same as that observed in spring-summer, but specific growth rate expressed as percent increase in leaf area per day was about half the maximum observedin late April and early May. No generative organs were produced. The number of leaves on a single shoot was 4.5 ± 0.7, and the plastochrone interval, i.e. the time interval between the initiation of two successive leaves, 13 ± 3 days. Growth was apparently regulated by light. Net production by eelgrass in Nabeta Bay in January was estimated to be 1.5 g dry wt. m −2 d −1 or 0.6 g C m −2 d −1.