< 1 day old planulae
10 months old
2 week old settled planulae
Reaggregation using various techniques
Hawaiian Pocillopora damicornis Babies Lead the Way to Reef Restoration
Chelsea S. Wolke, Norton T. Chan, David A. Gulko, Stephen P. Ranson, Laura Del Rio Torres
Hawaii Coral Restoration Nursery, Hawaii Division of Aquatic Resources, 1039 Sand Island Parkway Honolulu, HI 96819 USA
Acknowledgements
This project was funded in part with generous
support from the Hawaii Division of Boating and
Ocean Recreation.
Mission
Approach
Future of our Reefs
Hawaii’s Coral Restoration Nursery focuses on innovative coral reef
restoration techniques without harvesting corals from a healthy reef,
while maintaining a reef’s ecological value, to mitigate planned and
unplanned impact events around the main Hawaiian Islands.
Frequent asexual planulation (versus sexual propagation) provides an
abundant supply of coral to be used in improving restoration
techniques. Monthly collection of planula from colonies of Hawaiian
Pocillopora damicornis have been successfully maintained, settled,
with the resulting small colonies used as source material for both
reaggregation into large colonies and other mitigation projects.
P. damicornis planulae have the potential to pave the way for other
restorative corals by providing further insight for successful
transplantation, artificial substrate preferences, reaggregation of
identical genotypes, and threshold tolerances to anthropogenic
stressors and climate change. The weekly planulae allow for a wide
variety of replicate experiments and assays, which can be used to
evaluate reef restoration trade offs (such as the cost required to
transplant corals onto a reef versus the effort to transplant individual
colonies) and impacts. This plentiful resource holds the potential of
becoming the new “lab rat” for reef experimentation while providing
critical source material for reef restoration.
10-15 cm diameter P. damicornis colonies were collected from
Kaneohe Bay, Oahu during the summer months of 2015. Colonies
were kept in separate 2.7 L bowls and colony-specific planulae were
collected in 1 L containers with a 180 micron screen mesh window
(figure 1). Collectors were assessed for coral larvae daily. Planulae
were added to settlement tanks and grown-out under optimal conditions
(i.e. feeding, controlled sedimentation, water temperature and light, and
protection from predation and disease) until small colony formation.
Reaggregation consisted of attaching approximately 3 cm tall colonies
onto artificial substrates within close proximity to each other, allowing
branching tips to fuse and form one large colony (figure 2).
Figure 1. P. damicornis planula table and planula collectors (top right).
Photo (planula table): Jeff KuwabaraFor More Information : Chelsea Wolke
What does this mean?
The ability to cultivate asexual planulae in a controlled environment
quickly provides the following:
- P. damicornis is a colonizing species. While it is amongst the
fastest growing of the Hawaiian species, our method allows for
placement of large P. damicornis colonies onto reefs at rates far
faster than it can occur in the wild.
- This method provides us with a large volume of active planulae
which can be introduced either directly onto reefs for settlement or
settled within our nursery and transplanted as small colonies,
allowing a jumpstart to P. damicornis on restored reef
environments.
- P. damicornis is extremely sensitive to environmental
perturbations, allowing the use of these settled colonies to function
as “canaries in the coal mine” (or indicator species) for a variety of
potential environmental impacts to Hawaiian reefs.
- Ability to test impacts and assays on replicate corals with minimal
variation issues and with no impact to wild source colonies.
Literature Cited
Minton, D. 2013. Review of Growth Rates for Indo-Pacific Corals
Final Report. National Oceanic and Atmospheric Administration
Contract: RA-133F-12-SE-1246. 18pp.
Figure 2. P. damicornis in-situ growth versus the nursery’s restoration pathway.
Reaggregation Point
Reagreggated Colony
7 – 11 years old
Healthy Reproductive Colony
CORAL NURSERY
GROWTH RATE
1-3 YEARS
1.5 years old
Healthy Reproductive Colony
4 cm3 cm
10-15 cm
10-15 cm
2 mm
2 mm
NATURAL GROWTH
RATE
7-11 YEARS
