Data Parameters and Units:
Murawski PAH All— SampleNumber, SetName, SampleType, Animal ID, Species, Specimen Info, SampleWt (g), dNPH RecoveryFormat, dACE RecoveryFormat, dPER RecoveryFormat, CalcBasis, PAH species concentrations (ng/g) [NPH, C1NPH, C2NPH, C3NPH, C4NPH, ACY, ACE, FLU, C1FLU, C2FLU, C3FLU, DBT, C1DBT, C2DBT, C3DBT, C4DBT, PHN, ANT, C1PHN, C2PHN, C3PHN, C4PHN, SumLMWAlkyls Conc Format, FLA, PYR, C1FLA, C2FLA, C3FLA, C4FLA, BAA, CHR, C1CHR, C2CHR, C3CHR, C4CHR, BBF, BKF, BEP, BAP, PER, IDP, DBA, BZP, SumHMWAlkyls Conc Format, SumPAHAlkyls Conc Format], ReportingFlagNoteAH, SampleNote. * Note concentrations with a leading "less than" indicate below detection limits with the procedures used. 2011 Bile Data Combined—FIELD NUMBER, SITE, SPECIES [cobia, red snapper, greater amberjack, conger eel, yellowedge grouper], Volume of bile injected (µL), Naphthalene Equivalents (ng/g bile, wet wt.), Phenanthrene Equivalents (ng/g bile, wet wt.), Benzo[a]pyrene Equivalents (ng/g bile, wet wt.), Nap and Phen combined. Snyder PAH data 2012-2013—Year Sampled, Longline Station, Fish ID, Fish Common name [Blueline tilefish, Blackline tilefish, Golden tilefish, King snake eel, Yellow conger eel, Red snapper, Blackfin tuna, Snowy grouper, Southern hake, Gulf hake, Red grouper, Gag, Red porgy], Naphthalene equivalents (ug/g), Phenanthrene equivalents (ug/g), Benzo[a]pyene equivalents (ng/g). Sample Sites – Sample site, Latitude (decimal degree), Longitude (decimal degree). This spreadsheet contains a list of coordinates mentioned in the datasets.
Methods:
For muscle and liver samples obtained in 2011 a gas chromatography/mass spectrometry (GC/MS) method was employed to measure individual PAHs at low detection levels (<1 ng g-1) and provide data on alkylated homologs. The GC/MS method used to measure PAHs in fish species is a reliable and sensitive analytical method that has been used to measure these compounds in fish and other marine organisms collected after previous oil spills and natural disasters. For the GC/MS method, muscle and liver samples were extracted with dichloromethane using an accelerated solvent extractor. Polar compounds were removed from the extracts using a gravity flow silica/alumina column, followed by separation of PAHs from interfering biogenic compounds using liquid chromatography (LC) with size exclusion chromatography. PAHs were then measured on a low-resolution quadrupole GC/MS system. The calibration standards were duplicated relatively precisely. Methods blanks were run every 3-14 samples. Small amounts of a few analytes from the methods blanks were determined at background levels (primarily naphthalene and a few other PAHs) that averaged from 0.03 to 1.3 ng g-1. We did not adjust the sample results for the positive readings for the few instances of small positive readings because doing so would have resulted in negative PAH or homolog levels, and the overall effect on interpretation of results was minor. However, if such adjustments are made they would shift the dominant PAH homolog slightly from C2 to C3 naphthalene. High performance liquid chromatography with fluorescence detection. Sampling in 2011 occurred from July-August, using three chartered commercial longline fishing vessels. The depth distribution of sampling was 15-195 m along 15 transects from nearshore to offshore. The maximum depth of the survey coincided with the maximum depth distribution of red snapper, the species most often reported with skin lesions. For selected specimens we determined PAH levels in muscle and liver tissues and PAH metabolites in bile using standard methods. Sampling stations were located at nominal depths of 18, 37, 73, 110, 146 and 183 m along 15 transects extending from north of the Dry Tortugas Islands, to offshore from Terrebonne Bay, Louisiana. Some additional stations were located between transects, and for some transects with steep bathymetric slopes, we reduced the number of stations fished. The longitudinal scope of the study was set to encompass the majority of the area where surface oil concentrations during the DWH event were greatest, and also to include the West Florida Shelf region that had no observed surface oiling from the spill although we cannot rule out upwelling of dissolved DWH hydrocarbons there) to compare with the heavily-impacted NGM. At each pre-determined sampling location, the vessel captain searched for suitable habitat for target species including primarily snappers and groupers. This involved using the ship’s fish finder to locate “hard bottom” habitat typically also showing concentrations of demersal fishes. The vessel was allowed to range up to nine km from the center line of the sampling transect in search of suitable habitat. At each station, eight km of 3.2 mm galvanized steel main line was deployed, with 322-500 baited hooks. We used 91 kg test leaders, 3.7 m long attached to #13 circle hooks, with alternating cut fish and squid as bait. At the beginning and end of the main line we deployed Star:Oddi© CDST Centi temperature/time/depth recorders to record actual bottom time, as well as bottom temperature and depth fished. The recording interval of these instruments was 5 min. At set-out and haul-back we recorded latitude and longitude, time, depth from the vessel’s depth finder, the unique numbers of the TD instruments deployed at either end of the string, and local weather conditions. Once the longline was deployed, usually the vessel steamed back to the start buoy and began haul-back. The average soak time was 2 hours 1 minute. At retrieval, we determined fish species and recorded the standard, fork and total lengths to cm, as appropriate. Each specimen was weighed to the nearest g on a Marel© motion-compensated scale, or hand scale (nearest cg) for very large fish. Large sharks (e.g., ~2 m and greater) were photographed for species identification at the rail and released alive. Each fish obtained was inspected for a variety of externally-symptomatic diseases and other samples obtained. Average fish catch in 2011 was 47 per haul (range 4-240), the dominant species were red snapper, red grouper, Gulf smoothhound, and Atlantic sharpnose shark, which in aggregate accounted for about 2/3 of the total catch. In 2012 we added an additional survey transect at the Mississippi Valley, transect 16 west of the Mississippi River Delta (Figure 1B; Appendix 2) and one west of the previous limits of our survey (transect 17). Catches in 2012 consisted primarily king snake eel, Atlantic sharpnose shark, red snapper, Gulf smoothhound, and tilefish, also comprising about 2/3 of the catch. Our catches of large pelagic species were augmented by trolling surface lures while transiting between longline stations. Troll-caught specimens were processed using methods similar to longline catches. Each fish was examined for the following: (1) presence of external skin lesions (e.g., ulcers, or other external eruptions of the integument or skin irritation unrelated to mechanical damage, (2) the presence of fin rot disease, (3) gills examined for the presence of parasites (data not reported here) and tumors, (4) body inspected for evidence of recent mechanical damage, thought to occur through trauma of the catching process or due to predators, and (4) inspection of the skin and internal organs for the presence of obvious tumors and tumor-like growths. Photographs were taken of skin lesions and other pathologies and the status of each lesion was evaluated (e.g., open bloody ulcer, closed skin contusions, healing or old injury). For selected species (red snapper, red grouper, vermilion snapper, gag grouper, yellowedge grouper, snowy grouper, and tilefish) we chose a sub-set of normal and diseased specimens (up to 5 specimens of normal fish and all diseased fish per station) and weighed the liver, gastrointestinal tract, and gonad separately to g using the Marel© scale. We also took samples for PAH determinations from muscle and liver. Muscle samples were excised from the dorsal area and consisted of about 2 cm3 of tissue. Liver samples of similar size were also taken. Both liver and muscle samples were separately wrapped in two pieces of aluminum foil and inserted into plastic bags. Samples were kept on ice for the duration of each fishing vessel trip then frozen at -20˚C prior to analysis. Quality Assurance/Control: Quality assurance was monitored in four ways. 1) Prior to analysis of the 2012 and 2013 samples, an inter-laboratory comparison was completed to validate methods, precision and accuracy between the NWFSC and MML. The inter-lab comparison used three bile samples from 2011, from different species (cobia [Rachycentron canadum], greater amberjack [Seriola dumerili], red snapper [Lutjanus campechanus]) and over a wide range of concentrations (for NPH: 41 – 240 µg g-1; for PHN: 6.3 – 46 µg g-1, for BaP: 97 – 310 ng g-1). Prior to the inter-lab comparison, accuracy was monitored as part of the quality assurance plan at the NWFSC using a fish bile control sample (bile of Atlantic salmon [Salmo salar] exposed to 25 µg ml-1 of Monterey Crude oil for 48 hours). There was successful inter-laboratory agreement for the three bile samples, with a CV of less than 15%, for PAH equivalents for NPH, PHN and BaP. 2) A methanol solvent blank was run prior to every field sample. The area of the methanol blank was subtracted from the area of the field sample that was subsequently analyzed. 3) Each field sample was run in duplicate, with a CV of less than 15%. If the CV between duplicates was greater than 15%, the sample was run again in triplicate until the CV reached less than 15%. 4) A continuing calibration was used to monitor instrument stability throughout the entire analysis by running the quantifying standards of parent PAHs of NPH (2.5 µg ml-1), PHN (1 µg ml-1) and BaP (250 ng ml-1) every 12 field samples, making sure the CV remained less than 15%. Methods described in: Krahn, M.M., M.S. Myers, D.G. Burrows, and D.C Malins. 1984. Determination of xenobiotics in bile of fish from polluted waterways. Xenobiotica 14: 633-646. Krahn, M.M., G.M. Ylitalo, J. Buzitis, J.L. Bolton, C.A. Wigren, S.-L. Chan, and U. Varanasi. 1993. Analyses of petroleum-related contaminants in marine fish and sediments following the Gulf oil spill. Marine Pollution Bulletin 27: 285-292. Krahn, M.M., G.M. Ylitalo, and T.K. Collier. 2005. Analysis of bile of fish collected in coastal waters of the Gulf of Mexico potentially affected by Hurricane Katrina to determine recent exposure to polycyclic aromatic compounds (PACs). M.S. NOAA, National Marine Fisheries Service, Northwest Fisheries Science Center, Seattle, Washington. Ylitalo, G.M., M.M. Krahn, W.W. Dickhoff, J.E. Stein, C.C. Walker, C.L. Lassitter, E.S. Garrett, L.L. Desfosse, K.M. Mitchell, B.T. Noble, S.Wilson, N.B. Beck, R.A. Benner, P.N. Koufopoulos, and R.W. Dickey. 2012. Federal seafood safety response to the Deepwater Horizon oil spill. Proceedings of the National Academy of Sciences 109(50): 20274–20279. Krahn et al. 1984. Determination of metabolites of xenobiotics in the bile of fish from polluted waterways. Xenobiotica 14(8): 633-646. Murawski et al. 2014. Prevalence of external skin lesions and polycyclic aromatic hydrocarbon concentrations in Gulf of Mexico fishes, post-Deepwater Horizon. Transactions of the American Fisheries Society 143(4): 1084-1097.
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