Characterisation of polymorphic microsatellite markers in the widespread Australian seagrass, Posidonia Australis Hook. F. (Posidoniaceae), with cross-amplification in the sympatric P. Sinuosa

We developed 10 polymorphic microsatellite markers in the Australian seagrass Posidonia australis Hook. f. Markers were screened for their ability to detect within- and among-population genetic structure and variation. The markers showed a range in levels of polymorphism from fixed differences between the two sampled seagrass meadows to high levels of heterozygosity. These markers will be used to estimate gene flow across the species range, characterise the mating system through paternity analysis and pollen dispersal, characterise the nature and extent of clonality, and determine the genetic differentiation of local seagrass meadows to provide information on where to source local genetic provenance material for seagrass restoration projects. Seven of the 10 loci also amplified in the sympatric P. sinuosa and will be useful in future studies in population genetics and hybridisation. © Springer Science+Business Media B.V. 2009

Identifying critical recruitment bottlenecks limiting seedling establishment in a degraded seagrass ecosystem /631/158/854 /704/158/1745 article

© 2017 The Author(s). Identifying early life-stage transitions limiting seagrass recruitment could improve our ability to target demographic processes most responsive to management. Here we determine the magnitude of life-stage transitions along gradients in physical disturbance limiting seedling establishment for the marine angiosperm, Posidonia australis. Transition matrix models and sensitivity analyses were used to identify which transitions were critical for successful seedling establishment during the first year of seed recruitment and projection models were used to predict the most appropriate environments and seeding densities. Total survival probability of seedlings was low (0.001), however, transition probabilities between life-stages differed across the environmental gradients; seedling recruitment was affected by grazing and bioturbation prevailing during the first life-stage transition (1 month), and 4-6 months later during the third life-stage transition when establishing seedlings are physically removed by winter storms. Models projecting population growth from different starting seed densities showed that seeds could replace other more labour intensive and costly methods, such as transplanting adult shoots, if disturbances are moderated sufficiently and if large numbers of seed can be collected in sufficient quantity and delivered to restoration sites efficiently. These outcomes suggest that by improving management of early demographic processes, we could increase recruitment in restoration programs

Restoration of the seagrass Amphibolis antarctica - temporal variability and long-term success

The loss of seagrass meadows is an increasing problem worldwide. The important role that these meadows play in coastal ecosystems has resulted in substantial attention to the development of seagrass restoration techniques. Here, I present long-term (up to 5 years) results of seagrass restoration off the coast of Adelaide, South Australia, where >5,000 ha of seagrass has been lost and where trials of traditional restoration techniques using seeds and transplants have failed due to high levels of sand and water movement. Hessian (burlap) sandbags were deployed bimonthly (with some interruptions) from November 2007 to November 2012 (a total of 24 deployments), with a mix of single- and double-layered bags, to provide a stable substrate for naturally occurring Amphibolis seedlings to recruit to. At the end of the study (January 2013), bags deployed in August 2009 had similar stem densities to those found in adjacent natural meadows (15.2 ± 1.4 (SE) vs 18.6 ± 2.5). Bags deployed in May 2008 and August 2011 had 12.8 ± 2.3 and 13.2 ± 2.2 stems, respectively. Furthermore, stem lengths on older bags were greater than those on natural meadows (42.1 ± 4.2 after 62 months vs 30.2 ± 1.5 cm). While there was some interannual variation in recruitment success, the strongest predictor of success was deployment month. Bags deployed outside the austral winter recruitment season did not retain the ability to catch a large number of recruits, indicating that any restoration using this technique will have to be undertaken between approximately May and August to maximize chances of success.Jason E. Tanne

Challenges in Marine Restoration Ecology: How Techniques, Assessment Metrics, and Ecosystem Valuation Can Lead to Improved Restoration Success

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