< 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

chelsea.s.wolke@hawaii.gov

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