TY - JOUR
T1 - Growth rates and ages of deep-sea corals impacted by the Deepwater Horizon oil spill
AU - Prouty, Nancy G.
AU - Fisher, Charles R.
AU - Demopoulos, Amanda W J
AU - Druffel, Ellen R M
N1 - Funding Information:
We thank J. Chanton for providing input and supplementary radiocarbon data from the Gulf of Mexico, E. Cordes, H. White, C. Doughty, and A. Quattrini for helpful discussions and coral samples images, S. Griffin for radiocarbon analyses and M. Schulz for assistance with digital microscopy. We thank the crews of the R/V Atlantis, R/V Ron Brown and Holiday Chouest . The research cruises and geochemical analyses were funded by and NOAA and BP as part of the Deepwater Horizon oil spill Natural Resource Damage Assessment (NRDA). Funding for C.R.F. was provided by BOEM (BOEM contract #M08PC20038) awarded to TDI-Brooks International, with ship and ROV support from NOAA OER. Additional research and ship support was provided by NSF RAPID Grant OCE-1045083 and OCE-1064041 to C.R.F. Funding was provided to A. Demopoulos from the USGS Terrestrial, Freshwater, and Marine Environments Program through the Outer Continental shelf study Lophelia II: Rigs, Reefs, and Wrecks. Comments from M. McGann and two anonymous reviewers greatly improved the manuscript.
PY - 2016/7/1
Y1 - 2016/7/1
N2 - The impact of the April 2010 Deepwater Horizon (DWH) spill on deep-sea coral communities in the Gulf of Mexico (GoM) is still under investigation, as is the potential for these communities to recover. Impacts from the spill include observation of corals covered with flocculent material, with bare skeleton, excessive mucous production, sloughing tissue, and subsequent colonization of damaged areas by hydrozoans. Information on growth rates and life spans of deep-sea corals is important for understanding the vulnerability of these ecosystems to both natural and anthropogenic perturbations, as well as the likely duration of any observed adverse impacts. We report radiocarbon ages and radial and linear growth rates based on octocorals (Paramuricea spp. and Chrysogorgia sp.) collected in 2010 and 2011 from areas of the DWH impact. The oldest coral radiocarbon ages were measured on specimens collected 11 km to the SW of the oil spill from the Mississippi Canyon (MC) 344 site: 599 and 55 cal yr BP, suggesting continuous life spans of over 600 years for Paramuricea biscaya, the dominant coral species in the region. Calculated radial growth rates, between 0.34 μm yr-1 and 14.20 μm yr-1, are consistent with previously reported proteinaceous corals from the GoM. Anomalously low radiocarbon (δ14C) values for soft tissue from some corals indicate that these corals were feeding on particulate organic carbon derived from an admixture of modern surface carbon and a low 14C carbon source. Results from this work indicate fossil carbon could contribute 5-10% to the coral soft tissue δ14C signal within the area of the spill impact. The influence of a low 14C carbon source (e.g., petro-carbon) on the particulate organic carbon pool was observed at all sites within 30 km of the spill site, with the exception of MC118, which may have been outside of the dominant northeast-southwest zone of impact. The quantitatively assessed extreme longevity and slow growth rates documented here highlight the vulnerability of these long-lived deep sea coral species to disturbance.
AB - The impact of the April 2010 Deepwater Horizon (DWH) spill on deep-sea coral communities in the Gulf of Mexico (GoM) is still under investigation, as is the potential for these communities to recover. Impacts from the spill include observation of corals covered with flocculent material, with bare skeleton, excessive mucous production, sloughing tissue, and subsequent colonization of damaged areas by hydrozoans. Information on growth rates and life spans of deep-sea corals is important for understanding the vulnerability of these ecosystems to both natural and anthropogenic perturbations, as well as the likely duration of any observed adverse impacts. We report radiocarbon ages and radial and linear growth rates based on octocorals (Paramuricea spp. and Chrysogorgia sp.) collected in 2010 and 2011 from areas of the DWH impact. The oldest coral radiocarbon ages were measured on specimens collected 11 km to the SW of the oil spill from the Mississippi Canyon (MC) 344 site: 599 and 55 cal yr BP, suggesting continuous life spans of over 600 years for Paramuricea biscaya, the dominant coral species in the region. Calculated radial growth rates, between 0.34 μm yr-1 and 14.20 μm yr-1, are consistent with previously reported proteinaceous corals from the GoM. Anomalously low radiocarbon (δ14C) values for soft tissue from some corals indicate that these corals were feeding on particulate organic carbon derived from an admixture of modern surface carbon and a low 14C carbon source. Results from this work indicate fossil carbon could contribute 5-10% to the coral soft tissue δ14C signal within the area of the spill impact. The influence of a low 14C carbon source (e.g., petro-carbon) on the particulate organic carbon pool was observed at all sites within 30 km of the spill site, with the exception of MC118, which may have been outside of the dominant northeast-southwest zone of impact. The quantitatively assessed extreme longevity and slow growth rates documented here highlight the vulnerability of these long-lived deep sea coral species to disturbance.
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U2 - 10.1016/j.dsr2.2014.10.021
DO - 10.1016/j.dsr2.2014.10.021
M3 - Article
AN - SCOPUS:84973334099
VL - 129
SP - 196
EP - 212
JO - Deep-Sea Research Part II: Topical Studies in Oceanography
JF - Deep-Sea Research Part II: Topical Studies in Oceanography
SN - 0967-0645
ER -