Icon for: Sean Macduff


University of Hawaii at Manoa
Years in Grad School: 4

Judges’ Queries and Presenter’s Replies

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Presentation Discussion
  • Icon for: Brian Drayton

    Brian Drayton

    May 22, 2012 | 07:39 a.m.

    I enjoyed this poster. Two questions came to mind right away — if land-based stressors contributed to the proliferation of Avrainvillea (perhaps nutrient inputs from farming?), are these being addressed by community groups who have been working to restore the reef flat?
    Also: in my own experience with terrestrial invasives, the eradication effort has to bear in mind the persistence of propagules in the soil for a certain length of time (varying with species). How thorough does the eradication effort need to be, ultimately, to allow the restored system to be sustainable?

  • Icon for: Sean Macduff

    Sean Macduff

    Lead Presenter
    May 23, 2012 | 05:49 a.m.

    Land-based issues are definitely being addressed, not only by community groups, but also by governmental and academic institutions. One common goal is to reduce the velocity and volume of water rushing into streams and eventually into the ocean. Some potential solutions are the use of rain barrels and rain gardens by the residents of Maunalua Bay.

    Avrainvillea amadelpha is invasive – which means it is not easily removed. Manual removal does not remove all of the alga as some are missed. The community in Maunalua Bay is extremely dedicated and continues to maintain the algae at the Paiko Reef Flat restoration site.

    For complete sustainability, both marine and terrestrial systems need to be fixed and managed. The results from Paiko Reef Flat is the first step in restoration.

  • May 23, 2012 | 04:02 p.m.

    Nice presentation! This sounds like a great project. I have one question, just out of curiosity. When you are removing Avrainvillea, do you just pull it up by hand, or do you use some sort of tool, vacuum pump, etc? I’m assuming that the sediment gets pretty disturbed regardless of how you’re doing it, making it somewhat difficult to make sure that you’re effectively removing all of the organism.

  • Icon for: Sean Macduff

    Sean Macduff

    Lead Presenter
    May 24, 2012 | 04:59 a.m.

    Thanks. It was fun working on such a project. The Avrainvillea was removed by hand, placed in burlap bags, and transported to taro farmers to be used as fertilizer. The only special tools used were straw hats and gloves. You are right, there is a huge plume of resuspended sediment during alga removal. The team will revisit sites to make sure “most” of the alga was removed. Based on my observations, when a plot is cleared of the alga, it is almost 100% cleared.

  • May 25, 2012 | 12:18 p.m.

    That’s great that it can be used as fertilizer; finding a benefit for an organism considered to be a pest is something you don’t hear about very often!

  • Further posting is closed as the competition has ended.