Seagrass project restoring meadows

Now in its third year, the revolutionary seagrass transplanting project on Success Bank off Fremantle has restored the equivalent of a quarter-acre block of seagrass meadow.
      This innovative project, which is part of Cockburn Cement Ltd's five-year, $6 million Environmental Management Programme, is a real team effort with the success of the transplantation being overseen by Murdoch's Dr Eric Paling from Environmental Science.
      The transplantation has racked up a number of remarkable achievements already:

  • It is the first project in the world to use a mechanical harvester;
  • It is the biggest area ever to attempt to revegetate;
  • It uses the largest sods (1/4 sqm) ever to be transplanted;
  • Over 1400 sods have been planted; and
  • It boasts a survival rate of 50-80 per cent.
     Since late 1996 the team of Murdoch researchers, including research fellow Dr Mike van Keulen and research assistant Karen Wheeler, have been working with underwater engineers and commercial drivers on the Ecosub 1 -- a three-tonne underwater "turf cutter".
     The project is part of a massive dredging operation of shellsand by Cockburn Cement. The shellsand (90 per cent calcium carbonate) is used as lime in industrial processing of alumina, gold and mineral sands.
     The rehabilitation team is taking quarter-square-metre sods of seagrass (including roots and surrounding sand) from areas that are in the path of the dredger and moving them to safe ground.
     Three major species are being shifted -- Posidonia sinuosa, Posidonia coriacea and Amphibolis griffithii. The seagrass meadows contribute to the marine environment by harbouring other plants, young fish and crustacea, and forming the basis of the food chain.
     As part of the rehabilitation project, the researchers are studying the success of the newly-planted areas and monitoring factors like sand drift and storm effects.
     "We had some particularly severe storms last winter, which have knocked the seagrass about a bit," said Dr Paling. As a result the remarkable 80 per cent success rate that was being recorded had diminished to just over 50 per cent overall. He said the new sods had shown signs of spreading and that harvested areas had also shown regrowth.
     The project has already dispelled the popular belief that transplanted seagrasses do not regrow or spread.
Map of mining and restoration area
     
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