Monday, September 06, 2010

Projects Galore!

We've been working on a variety of projects while the volunteers were here and since they left.  Here's a short snapshot of them:
  • Collecting short cores to determine what's building the reef in various places (e.g., corals, coralline algae, etc.).  We've collected 4-inch or so cores at 2 different sites using a pneumatic drill and scuba tanks.  Each tank lasts about 5 minutes, so the main effort is carrying tanks to the site and on the reef crest!  Here’s a photo of Anne and Don coring on the reef crest at Reef Hotel.
  • Sediment coring to determine how sediment production and distribution has changed through time.  Originally, we were going to use a gas-powered hydraulic pump powering a vibra-corer designed by Anne’s undergraduate mentor Dennis Hubbard, but instead we tried a pneumatic vibrator powered by scuba tanks.  Unfortunately, it’s not as powerful, so it’s difficult to use in water deeper than waist-deep and doesn’t collect cores as long as we had hoped.
  • Deploying a video camera to observe life on the reef when we’re not there.  We plan to use the video camera to answer questions such as: how much do urchins move around and how much of the day do pearl oysters spend
    Unfortunately, the video camera is very complicated, so we’ve had problems convincing it to work!
  • Deploying temperature loggers to record water temperature right next to corals every 15 minutes for a year or more.  We already had 9 deployed around the atoll and are deploying 6 more this year.  Here is a photo of Anne deploying stakes to which we attach the temperature logger.
  • Measuring depth of the sand below the Cargo and Fuel Piers to determine how the shoreline changes year-to-year.  Our volunteers for the past three years have made this time-consuming endeavor possible and provided a lot of interesting information.  At left is a photo of volunteer Seiji measuring the depth using a transect tape with a weight at the end.
  • Collecting sea urchins and sea stars to help identify their skeletal fragments in the sediment.  We collected this very cool fine-spined urchin Leptodiadema purpurem during a sediment collection dive.
Now, in addition to continuing this projects, we're putting much of our effort into an experiment studying the feasibility of coral restoration on the reefs near the main island (Sand Island), which is a high priority for the Papahanaumokuakea Marine National Monument.  More on this project in the next blog post!

1 comment:

Barb said...

Wow; you folks are doing LOTS of projects; fascinating!