 |
| Pompom Island |
As mentioned in the
previous blog post, Pompom island marine
environment has large areas where the benthic type is that of a mobile rubble
slope. This degraded ecosystem is caused by dynamite fishing and generally has lower
biodiversity and fish density than the coral environment that preceded it. Here
at TRACC we are working upon methodologies to consolidate the rubble with the
hopes of returning it to the bio-diverse hotspot it once was. Mobile rubble
slopes present a difficult ecosystem for recolonizing of hard corals as newly
settled recruits often attach to a mobile piece of rubble and end up rolling
down the slope. Currently at TRACC we are using soft coral replantation
techniques to consolidate the rubble slope. Whitney Hoot and myself decided to
investigate this and see what effect, if any, the soft coral was having upon
the slope.
Firstly 3 different sites upon the north east side of the
island (house reef) were chosen. Sites were selected based on the following criteria;
benthic cover type (rubble), depth (~5m), slope angle (between 34-45 degrees),
distance below reef crest (1-2 meters) and crest characteristics (no coral
heads etc.).
Once sites were selected, 3 nets were deployed measuring 2x8
meters. To each of these nets two treatments and a control was added (thank you
to all the volunteers who participated in this). Treatments included cabling
tying soft coral to the net, cable tying bare rubble to the next and a control
on each side of the net.
After nets had been put in place and quality control had
been completed, 121 pieces of labeled and
painted rubble fragments were randomly added to the top of the quadrats in each
net. This was also repeated for the bottom of the nets using differently painted
corals. Our plan now is to track the progress of the rubble movement over time
to and see if there are any significant changes.
As well as rubble
movement every individual coral colonies was photographed , ID’d and measured
using imageJ software. Recording colony height, soft coral density and number
of runners will allow us to monitor the growth and survival rates of all the
soft corals in the experiment. And lastly i will monitor the benthic community structure that follows due to the change in environment.
 |
| A speedy nudibranch rushes to see what we're upto |
 |
| Whitneys ingenious labeling methodology |
