Seagrass beds found in shallow water, especially along tropical coastlines, can also suffer, with widespread impacts on both the immediate and surrounding environments. They stabilize the seabed, trap sediments, improve water quality, and directly nourish more than 340 species of marine fauna, which suffer when the food chain is disrupted. Some seagrass species are extremely fragile, dying on contact with crude oil and finding it very difficult to regenerate. Those with limited means of dispersal and low reproductive rates are particularly hard-hit in the long term, whereas species with higher reproductive rates recover more quickly. Threat to nesting areas Finally, the presence of oil in tropical coastal ecosystems can have serious consequences for species which nest in sand.
Eggs absorb moisture from the surrounding environment, and with it any hydrocarbons present.
Oil pollution in nesting areas can thus have catastrophic repercussions on reproduction. It delays the hatching of turtle eggs and causes abnormalities in the turtle shell, especially when the eggs are exposed to pollution during the early stages of development, though in the later stages, too, turtle embryos are very sensitive to the toxic effects of oil. Wild duck eggs are also susceptible to pollution. Embryos need to increase their oxygen intake as they develop, but oil can hinder their growth by blocking the egg pores, often resulting in death. Thus, the oil industry threatens many of the most important marine ecosystems in the tropics Elizabeth Bravo is Research Coordinator at the Oilwatch Secretariat, Quito, Ecuador.