Growth and organic production of eelgrass ( Zostera marina L.) in temperate waters of the pacific coast of Japan. I. Growth analysis in spring–summer

Abstract

The mode and dynamics of the growth of eelgrass ( Zostera marina L.) in Nabeta Bay, Japan, were investigated in a culture experiment in April–June. Two types of vegetative growth, that is, leaf elongation and new lateral shoot production, were distinguished. Formation of new leaves and defoliation were apparently synchronized, and numbers of leaves on a single vegetative shoot remained almost constant (5.5 ± 0.1). Maximum growth occurred in May. Generative (flowering) shoots were produced in May–June, and seed maturation was completed by the end of June. Mean life times of leaves on vegetative and generative shoots were 43.6 ± 1.0 and 38.7 ± 1.4 days, respectively. Net organic production by eelgrass in Nabeta Bay in June was estimated to be 7.2 g dry wt −2 day −1.