Raw sewage discharges.Highly turbid, nutrient-rich waters from:

An adjacent seawall construction site. Non-point sources (i.e., stormwater runoff). Adjacent river runoff (which is also home to a

garbage dumping site).

Elkhorn coral (Acropora palmata) populations across the wider Caribbean region were largely decimated over the last four decades. A total of 63 tagged coral colonies along 8

permanent transects (0.5 to 2.2 km downstream of the construction site) were unblemished before the event (seawall construction).

Increased levels of turbidity and sediment bedload, potentially from the seawall construction site, during August 13-20, 2010, caused significant localized coral mortality.

Frequency of impacted colonies increased up to 90% adjacent to the project site, and decreased with increasing distance.

A total of 90% of the corals were partially killed by patchy necrosis (PN) at each site.

45% of the colonies showed 26-50% recent tissue loss at the east, while 23% of those from the middle showed only 6-25% tissue loss.

Healthy communities may exist in very turbid environments (Pastorok & Bilyard 1985), but it may depend on the hydrology and currents of the system.

The main problem at Vega Baja is the high frequency of pollution pulses impacting the reefs.

Thus, we ask ourselves…

Are these pollution pulses impacting the threatened Elkhorn coral population?

And if so, How? And to what extent?

Initiated a long-term monitoring program to assess concentrations of:

PhosphateAmmoniaNitrate Nitrite

Along the coast and across permanent coral reef transects.Also, measurements for suspended solid material, turbidity and changes in coral conditions are taken.

Jesyka Meléndez-Rosa1, Edwin A. Hernández-Delgado2, Alejandra Alvarado2, Ricardo Laureano3

1Department of Biology, University of Puerto Rico, Cayey, 2University of Puerto Rico, Center for Applied Ecology and Conservation, Coral Reef Research Group, 3Vegabajeños Impulsando Desarrollo

Ambiental Sustentable

They are the principal builders of coral reef frameworks.

They remove and recycle carbon dioxide, thus buffering climate change impacts.

Shelter the land from harsh ocean storms and floods.

Provide resources for fisheries. Promote tourism.It is an intricate ecosystem and contains a

paramount biodiversity comparable with tropical forests.

Corals could potentially provide important anti-cancer drugs and a compound that blocks ultraviolet rays (Proksch et al. 2002).

Their skeletons are being used as bone substitutes in reconstructive bone surgery (Yun-Chun Wu et al. 2007).

They provide a living laboratory. Healthy reefs represent the principal source of

proteins, income and livelihood of coastal communities across multiple developing nations.

…of Vega Baja, Puerto Rico, lies one the largest threatened Elkhorn coral (Acropora palmata) remnant populations on the U.S. Caribbean.

Right,map of the island of

Puerto Rico. The pink shade indicates the

municipality of Vega Baja. The star, the

Elkhorn coral hot spot.

Far and near left, photos of Acropora palmata (Elkhorn coral).

A, photo depicting the heavy sedimentation near the seawall construction site B, photo of the seawall construction site. C, photo of raw sewage discharge into beach. D, photo of water sediment barriers not properly installed.

A B

C D

Map of the Elkhorn coral distribution across the Vega Baja shore. The long yellow arrows indicate the important water currents that flow from east to west. The short arrows indicate sewage discharge tube locations. The line drawn on the shore indicates the seawall construction site.

Percent of A. palmata colonies impacted by partial tissue mortality across a distance gradient from the rip-rap expansion project.

Ammonia concentrations.

Turbidity levels.

Phosphate concentrations.

Nitrate concentrations. Nitrite concentrations.

ACKNOWLEDGEMENTS

Edwin Hernández Ph.D., Alejandra Alvarado, Ricardo Laureano. The EPA (Environmental Protection Agency) GRO (Greater Research Opportunities) Fellowship Program. MA- 91721201-0.Center for Applied Ecology and Conservation, Coral Reef Research Group. I wish to extend a special thanks to the RISE program and its entire staff for their always enthusiastic support and guidance.

Recurrent sediment bedload from adjacent renourished beaches and a seawall construction site, as well as turbid and sewage-polluted non-point source runoff pulses, have been devastating to Elkhorn coral stands.

These violations to existing State and Federal regulations must be prevented in order to prevent further degradation of these highly vulnerable communities, as well as the continuous decline of its ecosystem resilience, functions and services.

REFERENCES

Yu-Chun Wu, Tzer-Min Lee, Kuo-Hsun Chin, Shyn-Tu Shaw & Chyun-Yu Yan, 2007. A Comparative Study of the Physical and Mechanical Properties of Three Natural Corals based on the Criteria for Bone-Tissue Engineering Scaffolds. Journal of Materials Science: Materials in Medicine 20(6): 1273- 1280P. Proksch, R. Edrada & R. Ebel, 2002. Drugs from the Seas: Current Status and Microbiological Implications. Applied Microbiology & Biotechnology 59(2-3): 125-134R.A. Pastorok & G. R. Bilyard, 1985. Effects of Sewage Pollution of Coral Reef Communitites. Mar. Ecol. Prog. Ser. 21: 175-189

Above, photos of corals affected by patchy necrosis and one case of black band disease in Diploria strigosa (bottom right).