Print PageSea-dumped munitions occur in every ocean of the world. More than 40 countries are beginning to address these issues within their territorial waters. While the human carcinogenic properties of many explosive compounds are known, their concentration in the marine environment and effect on marine organisms is poorly known.
From 1943 to 2002, land and sea areas on the eastern end of Isla de Vieques, Puerto Rico were used as a naval gunnery and bombing range. We estimate that 600 million pounds of high explosives were dropped on the island during this period, and that more than 2 million pounds of underwater unexploded ordnance (UWUXO) remain. Underwater radiological, biological, and chemical surveys were conducted to assay the health of coral reefs on Vieques.
Results/Conclusions
Biotic surveys show a statistically significant inverse correlation between the density of military ordnance and several measures of coral reef health, including (a) the number of coral species (p = 0.007), (b) the number of coral colonies (p = 0.02), and (c) coral species diversity (H’) (p = 0.0005). Reefs with the highest concentrations of bombs and bomb fragments have the lowest environmental health indices.
Water, sediment, and biotic samples revealed that: (a) every animal tested on the seaward reef of Vieques near UWUXO contained at least one potentially toxic compound which had leached from adjacent munitions [1,3,5-Trinitrobenzene; 1,3-Dinitrobenzene; 2,4-Dinitrotoluene + 2,6-Dinitrotoluene; 1,3-Dinitrobenzene; 4-Nitrotoluene; 2,4,6-Trinitrotoluene; 2-Nitrotoluene; Hexahydro-1,3,5-Trinitrotriazine; 4-Nitrotoluene]; (b) concentrations of these substances in fish and lobster tested do not exceed EPA’s Risk Based Concentrations (RBC) for commercially edible seafood; but (c) concentrations of these substances in several of the non-commercial species tested (e.g., feather duster worms, corals, and sea urchins) greatly exceed allowable RBC concentrations. For chromium in sediments, and for TNT in both water and sediment, there is an exponential decline in toxicant concentration with increasing distance from UWUXO. An organism's mobility and proximity to UWUXO determine its body burden of toxic compounds.
Since the concentration of explosive compounds is highest near unexploded bombs, we recommend that UWUXO on the surface of Vieques coral reefs be picked up and removed. We assert that this action will have an immediate, beneficial effect on the coral reef ecosystem by removing these point sources of pollution from the environment.
