Ecological Connectivity in Northeastern Gulf of Mexico – The Deep-C Initiative

ABSTRACT The Deepwater Horizon blowout injected massive quantities of carbon in the form of crude oil and gas into the otherwise oligotrophic northeastern Gulf of Mexico. This sudden and unprecedented event dramatically affected ecosystem function, reverberating throughout the physical, chemical, and biological realms. Characterizing the acute and chronic effects of the spill set the stage for the Deep-C Consortium's focus on the geomorphologic, hydrologic, and biogeochemical settings that influence the distribution and fate of oil and its impact on the ecology in the region. Detecting the chemical constituents of oil and the decay rates and by-products of biodegradation has enhanced our qualitative and quantitative accounting of “missing” oil and allowed the assessment of the sensitivity of marine organisms to specific compounds. The delayed response of oil-eating microbes created lags in carbon biodegradation that allowed ecological damage to occur. Microbes themselves appear to serve as conduits delivering petroleum-based carbon to marine food webs. While this carbon appears at the other end of the trophic spectrum — in deep-sea animals either actually or virtually unknown to science — the levels measured in their tissues are relatively low, which begs the question, “Does oil exposure affect their life history and general health?” To address this question and predict the long-term ecological effects of the Deepwater Horizon oil spill, we are incorporating historical and newly-derived data into linked food web-earth system models that can forecast how spills impact ecological and economic communities, including human health. This approach also provides a powerful tool for identifying data gaps that require our attention, and assessing the influences of hydrocarbon releases on biological productivity in the Gulf of Mexico ecosystem.