Early Life Stages of Algae

We are exploring factors that affect the post-settlement survival of dominant Fucoids in the intertidal zone, such as Durvillea, Cystophora, and Hormosira. These factors include the effects of shore height, grazing, wave exposure, sedimentation, competition, and the importance of 'stickability', as seen in the graph below. Durvillea, which is found on highly exposed shores at low tide, has zygotes that are covered in a highly adhesive mucilage which allows it to stay attached to the rock shortly after settlement time.

The average percent survival of Durvillaea, Cystophora, and Hormosira after exposure to a single wave after 1-, 6- or 12-h post-settlement attachment time.

The average percent survival of Durvillaea, Cystophora, and Hormosira after exposure to a single wave after 1-, 6- or 12-h post-settlement attachment time.

Image from: D.I. Taylor, D.R. Schiel / J. Exp. Mar. Biol. Ecol. 290 (2003) 229–245

We are currently working under the Marsden fund to further explore the micro-scale processes involved in the attachment of macroalgal zygotes within turbulent boundary layers. The boundary layer is the layer of fluid adjacent to the substratum that has virtually no velocity. Although it may be only a fraction of a millimeter thick, this viscious sublayer could present a substantial barrier to the attachment of algal rhizoids. This research integrates fluid dynamics, chemistry, and ecology in order to understand the settlement and adhesion of algae at the substratum.

New Zealand Marine Sciences 2005 Poster (PDF), S. Delaux, C. L. Stevens, S. Popinet and D. R. Schiel, Hydrodynamic modelling of seaweed zygotes attachment/detachment on a rocky substrate.