Marine Biology

, Volume 61, Issue 1, pp 21–26

Inhibition of the growth of micro-algae and bacteria by extracts of eelgrass (Zostera marina) leaves

  • Paul G. Harrison
  • A. T. Chan

DOI: 10.1007/BF00410338

Cite this article as:
Harrison, P.G. & Chan, A.T. Mar. Biol. (1980) 61: 21. doi:10.1007/BF00410338


The effects of the water-soluble fraction of dead leaves of the eelgrass Zostera marina L. on the growth of 8 species of micro-algae (pennate and centric diatoms, dinoflagellates, and a green flagellate) and a bacterium were studied on agar plates and in liquid culture. The extracts of leaves which had been dead from a few days to 2 wk inhibited growth and often killed cells in all test organisms. Extracts were lethal even at concentrations equivalent to as little as 0.25 mg dry leaf ml-1, but inhibition decreased when extracts were prepared from leaves aged in the laboratory for 35 d (loss of anti-bacterial activity) or 90 d (loss of anti-algal activity). Extracts of leaves which had aged and dried several months in the field had no effect, except at very high concentrations (13 mg dry leaf ml-1) when the lag phase of growth was prolonged several days in a culture of the chlorophyte Platymonas sp. The active fraction in eelgrass leaves may be important in controlling initial growth of micro-organisms on eelgrass detritus, and it could determine the composition and activity of the epiphytic community on living leaves.

Copyright information

© Springer-Verlag 1980

Authors and Affiliations

  • Paul G. Harrison
    • 1
  • A. T. Chan
    • 2
  1. 1.Department of BotanyUniversity of British ColumbiaVancouverCanada
  2. 2.Department of OceanographyUniversity of British ColumbiaVancouverCanada