Marine Ecology and Restoration
Ecological restoration of seagrass ecosystems is a complex process involving intimate knowledge of the many biological, chemical and physical interactions within seagrass ecosystems. At the Botanic Gardens and Parks Authority, our team develops science-based practical approaches that integrate principles of conservation and population ecology to achieve restoration goals.
We have developed innovative aquaculture technology to store, grow, and enhance the growth of seagrass propagules in tank culture systems, much in the same way that terrestrial nursery’s operate. We also use tank culture systems to better understand the ecophysiology of seagrasses as well as to test new restoration technologies prior to field transfer. For example, we have developed ‘growbags’ – hessian bags filled with a sediment mix that enhances seagrass vigour.
More recently, we are applying terrestrial-based theory and practice to improve seedling establishment. For example, we quantify early life-stage transitions, identifying which of these transitions are the most limiting in seagrass seedling recruitment. With this knowledge we can target those transitions that will be most responsive to management.
We are using microsatellite DNA markers developed for Posidonia australis to study clonal diversity, mating system, long distance dispersal, and recruitment, and what their overall contributions are to population genetic structure. The markers have considerable diversity and allow us to improve our understanding of the contribution of sexual reproduction in this species through estimation of mating system parameters (genotyping shoots and fruits) and using genetic assignment procedures for identification of pollen dispersal distance. Given the high annual seed production, particularly in Western Australian meadows, and dispersal of floating seeds via wind and wave action, the potential for long distance dispersal in P. australis is high, so we are using genetic assignment procedures of groups of floating seeds to determine dispersal from maternal meadows.
Seagrasses are a diverse array of marine flowering plants growing along most of the world’s coastlines. Seagrasses underwent dramatic modifications to facilitate their survival in and colonization of the submerged marine environment including physiological changes to cope with salinity, with the evolution of hydrophily (underwater pollination) representing a major evolutionary shift.
Current Marine Restoration Ecology research projects are:
- Overcoming critical recruitment bottlenecks limiting seeding establishment in degraded seagrass ecosystems: a systems approach to restoration. ARC Linkage project (2013 - 2016). Collaborators: Prof Gary Kendrick (UWA), Prof Carlos Duarte (UWA), Prof Kingsley Dixon (BGPA), Dr David Merritt (BGPA), Prof Robert Orth (VIMS), Mrs Eefje Broenland (Mitsui) and Mr Michael Williams (Cockburn Cement). Industry partners: WA Botanic Gardens and Parks Authority; Cockburn Cement Ltd; Mitsui Pty Ltd.