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CONTENTS
Executive Summary
Glossary of Technical Terms, Acronyms, and Units of Measure
Chemical Structures of Organic Analytes (PDF)
Introduction
Methods
Results and Discussion
Conclusions
Acknowledgments
References Cited

NOAA Technical Memorandum NMFS-NE-157

Contaminant levels in muscle of four species of recreational fish from the New York Bight apex

Ashok Deshpande1, Andrew F.J. Draxler1, Vincent S. Zdanowicz1,2, Mary E. Schrock3, Anthony J. Paulson1, Tom W. Finneran1, Beth L. Sharack1, Kathy Corbo1, Linda Arlen1, Elizabeth A. Leimburg1, Bruce W. Dockum1, Robert A. Pikanowski1, Brian May4, and Lisa B. Rosman4,5
1National Marine Fisheries Serv., 74 Magruder Rd., Highlands, NJ 07732
2Current address: U.S. Customs Serv., Research Lab., 7501 Boston Blvd., Ste. 113, Springfield, VA 22153
3Battelle Memorial Inst., 505 King Ave., Columbus, OH 43201-2693
4U.S. Army Corps of Engineers, 26 Federal Plaza, New York, NY 10278-0090
5Current Address: National Ocean Serv., 290 Broadway, Rm. 1831, New York, NY 10007

Web version posted June 13, 2001

Citation: Deshpande A, Draxler AFJ, Zdanowicz VS, Schrock ME, Paulson AJ, Finneran TW, Sharack BL, Corbo K, Arlen L, Leimburg EA, Dockum BW, Pikanowski RA, May B, Rosman LB. 2000. Contaminant levels in muscle of four species of recreational fish from the New York Bight apex. NOAA Tech Memo NMFS NE 157; 99 p.

Information Quality Act Compliance: In accordance with section 515 of Public Law 106-554, the Northeast Fisheries Science Center completed both technical and policy reviews for this report. These predissemination reviews are on file at the NEFSC Editorial Office.

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Executive Summary

A survey was conducted to establish a benchmark for concentrations of selected trace metals and organic contaminants in the edible flesh of four species of fish important to the recreational fishery of the New York Bight Apex. Bluefish (Pomatomus saltatrix), summer flounder (Paralichthys dentatus), black sea bass (Centropristes striatus), and tautog (Tautoga onitis) were caught by rod and reel during September-December 1993 at 15 sites in the New York Bight Apex. Fourteen composite samples of muscle tissue from each fish species were analyzed for 9 trace metals, 25 polychlorinated biphenyl (PCB) congeners, 17 organochlorine pesticides, 24 polycyclic aromatic hydrocarbons (PAHs), seven 2,3,7,8-substituted polychlorinated dibenzo[p]dioxins (PCDDs), and ten 2,3,7,8-substituted polychlorinated dibenzofurans (PCDFs).

Concentrations of trace metals were low and within the range of values normally found in muscle tissues of finfish from relatively pristine ecosystems. Total mercury levels in all fish composites were <0.11 µg/g (ppm) wet weight, which is an order of magnitude below the U.S. Food and Drug Administration (FDA) action level of 1.0 µ="3">g/g (ppm) wet weight for methylmercury.

PCB and organochlorine pesticide concentrations were relatively low and were related to the lipid content of the muscle tissue. The “Aroclor-based” estimates (see “Glossary...” for definition) for all composite samples were below the FDA tolerance level of 2.0 µg/g (ppm) wet weight for PCBs. Average sums of 23 PCB congeners were 0.37 µg/g for bluefish, <0.05 µg/g (i.e., below the detection limit) for summer flounder, 0.08 µg/g for black sea bass, and 0.06 µg/g for tautog.

Average sums of DDTs and their metabolites for all composite samples were well below the FDA action level of 5.0 µg/g (ppm) wet weight. Average sums of DDTs and their metabolites were 0.16 µg/g for bluefish, <0.009 µg/g (i.e., below the detection limit) for summer flounder, 0.02 µg/g for black sea bass, and 0.014 µg/g for tautog.

Average sums of chlordanes for each species, which ranged from 0.04 to 0.08 µg/g, were below the FDA action level of 0.3 µg/g (ppm) wet weight.

With few exceptions, PAHs were undetected.

Concentrations of 2,3,7,8-tetrachlorodibenzo[p]dioxin (TCDD) in all composite samples were below the FDA advisory level of 25 pg/g (pptr) wet weight for limited consumption. Concentrations of 2,3,7,8-TCDD were below the method detection limit of 1.63 pg/g in all summer flounder and black sea bass composites, 10 of 14 tautog composites, and 4 of 14 bluefish composites. The concentrations of 2,3,7,8-TCDD were near the detection limit in the 4 remaining tautog composites, and in 9 of 10 remaining bluefish composites. The remaining bluefish composite contained the highest concentrations of PCBs (0.57 µg/g), DDTs (0.27 µg/g), chlordanes (0.062 µg/g), and 2,3,7,8-TCDD (7.27 pg/g). This bluefish composite had the highest average composite weight, included the heaviest individual specimen, and had the highest lipid content.


INTRODUCTION

A survey was conducted to establish a benchmark for concentrations of selected trace metals and organic contaminants in the edible flesh of fish species important to the recreational fishery of the New York Bight Apex (i.e., the area bounded by the coasts of New Jersey and Long Island, 73°30’W longitude, and 40°15’N latitude; Bowman and Wunderlich 1976; Figure 1). Four species were targeted based on their importance to the recreational fishery, their life habits, and the regional ecology: bluefish, Pomatomus saltatrix (pelagic habitat); summer flounder, Paralichthys dentatus (demersal habitat); black sea bass, Centropristis striata (reef habitat); and tautog, Tautoga onitis (reef habitat). Refer to Figure 2 for species illustrations and synoptic descriptions of range, habitat use, spawning, stock structure, migratory behavior, predation, and management.

The survey collected and analyzed fish caught by local recreational fishermen during the fall when fish physiological condition and lipid (i.e., fat) levels would likely be highest. To the extent that any metal or contaminant concentration is positively associated with lipid levels, the timing of the sampling would be most useful from a public health standpoint. Measured concentrations were compared with the U.S. Food and Drug Administration’s guidelines for human consumption.


METHODS

SAMPLE COLLECTION, DISSECTION, AND COMPOSITING

Bluefish, summer flounder, black sea bass, and tautog were caught by rod and reel during September-December 1993 at 15 sites in the New York Bight Apex selected on the basis of their popularity with fishermen (Figure 1; Appendix Table A1). Site locations were determined by LORAN-C.

Guidelines of NOAA-FDA-EPA (1986) were used for handling the fish. Whole fish were returned to the laboratory on ice, and dissected within 48 hr. In the laboratory, each whole specimen was weighed to the nearest gram and measured to the nearest millimeter. Total length was measured for summer flounder, black sea bass, and tautog; fork length was measured for bluefish. Individual specimens were also examined for gross abnormalities and sex. In keeping with local consumption practices, fillets (i.e., boneless muscle tissue) of summer flounder and tautog were prepared with the skin and scales removed. Bluefish and black sea bass fillets included the skin, with the scales removed.

Dissections were performed in the laboratory under a high-efficiency particle air (HEPA) laminar-flow hood. Dissecting implements and containers were cleaned in a manner appropriate for the specific analyses. Implements were cleaned with ultrapure 10% nitric acid, double-deionized (DDI) water, methanol, and methylene chloride from a commercial supplier. Plastic containers for trace metals samples were washed in dilute Micro™ liquid laboratory cleaner, rinsed in tap water, washed in 10% nitric acid, triple rinsed in DDI water, and dried under a HEPA clean-air hood. For trace metal analyses, three adjoining pieces (approximately 2 cm3 each) of white muscle were excised from the anterior dorsal portion of each fillet and stored in acid-cleaned plastic vials at -20°C (Figure 3). For organic contaminant analyses, the remainder of each dorsal fillet was homogenized in a stainless steel blender, and stored in precleaned glass jars at -80°C. Both dorsal and ventral fillets from each summer flounder, and small samples from other species, were homogenized to obtain an adequate sample size.

Allocation of muscle tissue from individual specimens to composites was based on fish length. Outlier specimens for each species at each site were identified using the Dixon outlier test (Sokal and Rohlf 1981); those specimens were excluded from further consideration. The number of composites for each species for each station was based on the number of normally distributed specimens and the need for three specimens per composite. A random number was then assigned to each of the normally distributed specimens. Given that N specimens were to be composited for a specific station, we selected the N specimens with the lowest random number from the available specimen pool. For example, if five composites were to be prepared for a particular station, specimens with the lowest 15 random numbers were selected. The selected specimens were sorted by length and grouped in sets of three to form the five composites (Appendix Tables A2-A5). The specimens identified as outliers and those not randomly selected for the composite preparations are listed in Appendix Tables A6-A9.

SAMPLE ANALYSIS

Trace Metals

Analyses of nine trace metals (Appendix Table B1) in the muscle composite samples were performed in two separate batches following the procedures of Zdanowicz et al. (1993). Each batch included 28 muscle composites (i.e., 14 for each of two species), three replicates of dogfish liver standard reference material (SRM; DOLT-1, National Research Council of Canada), three method blanks, and one composite in duplicate for each of the two fish species. Quality assurance (QA) and quality control (QC) procedures included participation in the annual NOAA-NRC [National Research Council Canada] intercomparison exercise (Willie and Berman 1995).

Approximately 0.5 g of muscle from each of three individual specimens constituting a composite were placed in acid-cleaned teflon vials and dried overnight at 60-65°C. Five milliliters of ultrapure, concentrated nitric acid were added to each vial, and the vials were allowed to stand at room temperature for 2-4 hr. Vials were then placed inside teflon-lined bombs, and the tissue was digested overnight at 120°C. After cooling, the bombs were vented, the vials removed, and the digests allowed to degas at room temperature overnight. The digests were then quantitatively transferred to 25-ml glass graduated cylinders, brought to volume using double-deionized water, and analyzed for arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni), silver (Ag), and zinc (Zn) using atomic absorption spectrophotometry or inductively coupled plasma mass spectrometry. Wet weight and dry weight for each muscle composite were used in the percent water determinations.

PCBs, Organochlorine Pesticides, and PAHs

Analyses of 25 PCB congeners (Appendix Table B2), 17 organochlorine pesticides (Appendix Table B3), and 24 PAHs (Appendix Table B4) in muscle composites were performed in six separate batches following the guidelines of NOAA (Krahn et al. 1988; Sloan et al. 1993) and the EMAP [Environmental Monitoring and Assessment Program] procedures of the U.S. Environmental Protection Agency (EPA 1993a). Each batch of 24 extractions included one method blank, one matrix spike, one mussel tissue SRM (mussel tissue V, QA93TIS5 - SRM 1974a, NIST [National Institute of Standards and Technology]), and one muscle composite in triplicate. One batch included seven spiked replicates of a summer flounder muscle composite for the method detection limit (MDL) determination. The remaining soxhlet extraction setups in this latter batch were allocated to the analyses of other QA samples and the muscle composite samples. QA and QC procedures followed EMAP protocols (Valente et al. 1992), and included participation in the annual NIST/NOAA/NS&T/EPA EMAP intercomparison exercise (Parris 1995). A separate sample of each composite was dried overnight in an oven at 120°C, and reweighed to determine the percent wet weight (Appendix Tables A2-A5). Although all values in this report are wet weight concentrations, this measurement allows the reader to convert concentrations to a dry-weight basis. In addition, the lipid content of each composite was determined gravimetrically.

Approximately 4 g of muscle from each of the three individual specimens constituting a composite were placed in a mortar and mixed, using a pestle, with anhydrous sodium sulfate until the composite was dry. The mixture was soxhlet extracted with methylene chloride following NIST protocols (Wise et al. 1991). Twenty percent of the methylene chloride extract was evaporated to dryness for lipid determination. Silica gel/alumina/florisil column chromatography was used to remove the bulk biogenic and other polar interferences from the remaining extract. The cleaned fraction was further purified using size-exclusion, high-performance liquid chromatography (HPLC).

PCBs and chlorinated pesticides were analyzed by capillary gas chromatography with electron-capture detection (GC/ECD; EPA 1993a). Nomenclature for PCB compounds follows that of Ballschmiter and Zell (1980). Specific PCB congeners were not verified by gas chromatography - mass spectrometry (GC-MS), and the apparent concentrations of specific congeners may be affected by contribution(s) from the coeluting compound(s) (Appendix Table B2). PAHs were analyzed by capillary GC-MS in selected ion monitoring mode (EPA 1993a).

2,3,7,8-Substituted PCDD and PCDF Congeners

Dibenzo[p]dioxin and dibenzofuran are the base structures for two sets of compounds in which chlorine atoms are added to form PCDDs and PCDFs. There are 75 PCDD and 135 PCDF congeners. Those congeners with chlorine atoms in the 2,3,7, and 8 positions (of which there are 7 PCDDs and 10 PCDFs; Appendix Table B5) are considered toxic, with 2,3,7,8-TCDD being the most toxic of all PCDD and PCDF congeners (EPA 1989).

Muscle composites were analyzed for the seven 2,3,7,8-substituted PCDD congeners and ten 2,3,7,8-substituted PCDF congeners in three separate batches, using EPA Method 8290 with selected modifications from EPA Method 1613 (EPA 1993b, 1994; Battelle 1996). Each batch of 18-20 samples included one method blank, one matrix spike, one fish SRM (EDF-2526, Cambridge Isotope Laboratory), and one muscle composite in triplicate. One batch included four replicates of a summer flounder muscle composite for the MDL verification. Internal standards used in identification and quantification of PCDD and PCDF congeners were 13C-labeled analogs of each dioxin congener except for 1,2,3,7,8,9-hexachlorodibenzo[p]dioxin, and of each dibenzofuran except for octachlorodibenzofuran. Isomers of each homolog series were resolved on a DB-5 column and analyzed by high-resolution MS. Second-column confirmation of 2,3,7,8-TCDF levels above 1 pptr were performed on a DB-Dioxin column.

STATISTICAL TESTS

The nonparametric Kruskal-Wallis test (SAS 1989) was performed to examine the statistically significant differences among stations for those analytes in which the mean concentration value from at least one station was three times the method detection limit. For composites for which a specific congener was not detected, one-half perform the test of interstation differences.

The Spearman rank order correlation test was used to determine associations among PCBs, DDTs, lipid content, and average composite length. Nondetectable values were not used in the Spearman rank order correlation test.

QUALITY ASSURANCE

Precision and accuracy are the measures of QA determined in this study. For trace metals, QA for precision included analyses of MDLs and relative percent differences (RPDs), while for accuracy, it included comparative analyses with SRM. For organic contaminants, QA for precision included analyses of laboratory methods blanks, MDLs, and laboratory triplicates, while for accuracy, it included analyses of internal surrogate standards, matrix spike analytes, and SRM. The data quality objectives (DQOs) for organic analyses are listed in Appendix Table B6.

Trace Metals

The MDLs for each metal for each batch were computed as three times the standard deviation of six method blank measurements. The blank values were low and the MDLs were below 1 µg/g dry weight for all metals (Appendix Table B7). The percent recoveries of the nine metals in the DOLT-1 SRM varied between 92 and 104%. The relative standard deviations (RSD) of the dry weight measurements were 10% or less for all metals, except for Cr which had an RSD of 17%.

Based upon the percent water determination in muscles of different fish species (Appendix Tables A2-A5), a nominal water content of 75% was used for muscle composites for the purpose of determination of MDLs on a wet weight basis (Appendix Table B8). For duplicate fish tissue samples, the RPD was computed as the range divided by the mean and then multiplied by 100. Greater than 75% of the duplicate samples exhibited an RPD <20% based on wet weight, with much of the variation attributed to differences in the percent solids between duplicate fillets.

PCBs

GC/ECD analyses were performed on seven replicate solutions of each PCB congener (approximately 40 pg/µL of each congener, 1 µL injected). The instrumental detection limit (IDL) for each PCB congener was determined by multiplying the standard deviation for seven replicate measurements by a Student’s t value of 3.143 (EPA 1984b). None of the PCB replicate determinations exceeded the DQO criterion for IDL (Appendix Table B9). The estimated method detection limit (EMDL) for each PCB congener was calculated using the IDL and the nominal values of 10 g wet weight for sample size, 50% for extraction and cleanup recovery efficiency, 250 µL for final extraction volume, and 1 µL for GC injection volumes. The MDL for each PCB congener was determined on seven spiked replicates of summer flounder muscle composites following the procedure outlined in EPA (1984b). The RSD values were <10% for most replicate measurements in the MDL determination of PCB congeners (Appendix Table B10). The fact that the MDL is greater than the EMDL indicates that the method is limited by random variation in the recovery from samples at low concentrations rather than by the sensitivity of the instrument. None of the laboratory method blank values exceeded the DQO criterion (Appendix Table B6). Approximately 90% of laboratory triplicate values met the DQO criterion (Appendix Tables B11-B12).

Consistent recoveries (i.e., 85.3-94.9%) were found for the relatively nonvolatile BZ #198 (Appendix Tables B13-B16), while recoveries for the surrogate 4-4'-dibromooctafluorobiphenyl ranged between 46 and 70%. The higher apparent recoveries (i.e., 167%) of HPLC surrogate 1,2,3-trichlorobenzene (TCB) in bluefish may be due to the coelution of unknown interfering compound(s) with the TCB peak. Approximately 69% of PCB congeners (Appendix Table B17) met the matrix spike DQO criterion. For PCB congeners, 99% of analyses met the DQO criterion for analysis of accuracy based on reference material (Appendix Table B18).

Organochlorine Pesticides

GC/ECD analyses were performed on seven replicate solutions of organochlorine pesticides (approximately 40 pg/µL of each pesticide, 1 µL injected). The IDL for each pesticide analyte was determined by multiplying the standard deviation for seven replicate measurements by a Student’s t value of 3.143 (EPA 1984b). One of 19 pesticide replicate determinations exceeded the DQO criterion for IDL (Appendix Table B19), although this value (5.52%) was near the DQO target of 5%. The MDLs were determined on seven spiked replicates of summer flounder muscle composites following the procedure outlined in EPA (1984b), and were greater than the EMDLs. The RSD values were <10% for most replicate measurements in the MDL determination of pesticide analytes (Appendix Table B20). Approximately 65% of pesticide analytes met the DQO criterion for analysis of laboratory triplicate samples (Appendix Tables B21-B22).

Approximately 82% of recovery values for internal pesticide surrogate standards met the DQO criterion (Appendix Tables B13-B16). Approximately 79% of pesticide analytes met the matrix spike DQO criterion (Appendix Table B23). For pesticide analytes, 100% of the determinations met the DQO criterion for analysis of accuracy based on reference material (Appendix Table B24).

PAHs

GC-MS analyses were performed on seven replicate solutions of PAH analytes (approximately 200 pg/µL of each congener, 1 µL injected). The IDL for each PAH analyte was determined by multiplying the standard deviation for seven replicate measurements by a Student’s t value of 3.143 (EPA 1984b). Seven of 24 PAH replicate determinations exceeded the DQO criterion for IDL (Appendix Table B25a,b), although the highest RSD value was only 8.3%. The MDLs for PAH analytes were determined on seven spiked replicates of summer flounder muscle composites following the procedure outlined in the EPA (1984b). The overspiking of PAHs resulted in high MDL values. The reported detection limits for PAHs were computed from the replicate analyses of mussel tissue SRM (Appendix Table B26a,b). For four PAH compounds for which peaks were not found in the chromatograms, the detection limits were estimated to be 10 ppb wet weight based on the following assumptions: 1) 10 g wet weight of muscle tissue, 2) 50% efficiency in sample extraction and cleanup steps, 3) 250 µL as the final sample volume, and 4) an IDL (i.e., GC-MS) of 200 pg/µL. Of the three samples that exhibited one PAH value above the MDL, all analyses met the DQO for analysis of laboratory triplicates (Appendix Tables B27a,b, B28a,b).

Approximately 75% of recovery values for internal surrogate standards met the DQO criterion (Appendix Tables B13-16). The low recoveries (i.e., 23%) for deuterium-labeled naphthalene are not unexpected considering the volatility of this compound. Only 37.5% of PAH determinations (Appendix Table B29a,b) met the matrix spike DQO criterion. The matrix spike recovery data for PAHs are apparently skewed by the low-molecular-weight PAHs. These compounds are somewhat more volatile than their high-molecular-weight counterparts, and thus, are prone to evaporative losses during sample preparation. There seems to be no apparent explanation for the lower recoveries of perylene. The analysis of NIST SRM 1974a (intercomparison sample QA93TIS5) with each analytical batch indicates good precision from batch to batch, although this material contained low concentrations of contaminants (Appendix Table B30).

2,3,7,8-Substituted PCDD and PCDF Congeners

The MDLs for the PCDD and PCDF congeners were calculated using only three replicates because one of the four replicates used in the MDL verification exercise was lost during preparation (Appendix Table B31a,b). None of the laboratory triplicate analyses exceeded the DQO criterion of #25% RSD for analytes that had concentrations greater than 10 times the MDL (Appendix Tables B32a,b, B33a,b).

Approximately 98% of internal surrogates and 96% of cleanup surrogates for dioxin analyses met the DQO criterion (Appendix >Tables B34a,b-37a,b). Recoveries of internal surrogate standards varied from 7 to 116%, with an average of 73% (RSD = 21%). Recoveries of a cleanup standard, in which all four chlorines of 2,3,7,8-TCDD were labeled with 37Cl, ranged from 16 to 385%, with an average of 104% (RSD = 41%). All internal standard DQOs were exceeded for one tautog composite (i.e., composite #155). For tautog composite #155, the average recovery of congeners in which all 12 carbons were labeled with 13C was 12.1% (range of 7-17%), and the recovery of the cleanup standard, 37Cl-labeled 2,3,7,8-TCDD, was 16%. The highest recovery for this composite is below the lowest recovery in any other composite (i.e., 29%). Therefore, values for tautog composite #155 should be used with caution.

Approximately 94% of the matrix spike analytes met the DQO criterion (Appendix Table B38a,b). None of the PCDD and PCDF analyses of the accuracy-based SRM exceeded the DQO criterion (Appendix Table B39a,b).

Quality Assurance Summary

The MDLs for metals were low, and the accuracy and precision of the SRM measurements were generally within 10%. Duplicate analysis of fish tissue samples resulted in RPD measurements which exceeded 20% in 25% of the samples, partially due to differences in tissue density.

For organic contaminants, some of the quality assurance goals were not met, but the overall quality assurance compliance is judged typical of organic analytical data. The potential exists that organic data can be affected by interfering compounds coeluting with contaminant analyte peaks. Because each sample matrix is different, methods do not exist for adjustment of the data for these variations. The number of replicates per site, the number of fish per composite, and the agreement with other laboratories participating in the NIST/NOAA/NS&T/EPA EMAP intercomparison exercise do, however, provide confidence in the final estimates. As a practical matter, the general conclusions derived from this survey are not limited by the quality assurance data, but data should be interpreted with caution for specific samples in which quality assurance goals were not met.


RESULTS AND DISCUSSION

GENERAL CHARACTERISTICS OF FISH COMPOSITES

Bluefish had significantly higher lipid content (i.e., 6.80%) than the other three species (Figure 4A). Tautog and black sea bass had similar lipid content (i.e., 2.03 and 2.09%, respectively), while the lipid content of summer flounder was 0.56%. For all four species, there were no significant differences in lipid content among stations (Table 3, Appendix Tables A2-A5).

The bluefish caught at Station BL1 were shorter, lighter, and less dense (i.e., more water) than the bluefish caught at Stations BL2 and BL3. The black sea bass caught at Station SB1 had significantly higher water content than those caught at Stations SB2 and SB3. Within the four species, there was a significant correlation between average length of the composite and average weight (Table 1), in part because randomly selected specimens were sorted into composite samples by length.

A correlation between percent lipids and average length (or weight) was observed only for tautog (Table 1).


CONTAMINANT CONCENTRATIONS IN FISH COMPOSITES

Trace Metals

Complete listings of analytical results for metals in each composite are given in Appendix Tables C1-C4. Metal concentrations in all muscle composites were above the detection limits. These concentrations were generally low (Table 2) and well within the ranges expected for metals in muscle of fish from relatively uncontaminated locations. Values on a wet weight basis were <0.05 µg/g (ppm) for Ag; 0.1-0.5 µg/g for Cd, Cr, Cu, Ni, and Pb; 3.5-13.8 µg/g for Zn; and 0.4-3.8 µg/g for As. The Hg analyses in this study determined total Hg content, a measurement which encompasses all species of mercury present, including methyl mercury. The highest value of total mercury in this study was 0.11 µg/g which was an order of magnitude lower than the FDA action level of 1.0 µg/g wet weight for methyl mercury in fish or shellfish for human consumption (Kennedy 1979).

Statistically significant differences in metal concentrations among locations were not detected for any metal (i.e., P values > 0.05 for all metals for all species; Appendix Tables C1-C4). Therefore, data from all sites were pooled by species, and mean species concentrations (Table 2) were compared (Figure 5). The following significant differences in mean metal levels were found: Cr: bluefish = black sea bass > tautog = summer flounder; Zn: bluefish > tautog = summer flounder = black sea bass; As: black sea bass > summer flounder > tautog > bluefish; and Hg: tautog = bluefish > summer flounder = black sea bass.

These differences are probably related to the unique nature, diet, and behavior of each species. It is not uncommon to find differences in contaminant levels among species (Zdanowicz et al. 1992). The differences, however, do not appear to be related to habitat type.

PCBs

A significant number of composite-congener combinations had PCB concentrations that were below the MDL (i.e., 20% for bluefish, 91% for summer flounder, 57% for black sea bass, and 63% for tautog). Two PCB congeners were not detected in any composite (Appendix Table C5), and were not included in subsequent calculations. Complete listings of analytical results for PCB concentrations for each composite are given in Appendix Tables C6-C9.

Of the 16 PCB congeners which were found in bluefish and which were statistically analyzed (Appendix Table C6), two low-concentration congeners (i.e., BZ #8 and BZ #128) and one high-concentration congener (i.e., BZ #153) were found to be significantly higher at Station BL3 (P < 0.05). Differences among the stations were not observed for the remaining 13 congeners, nor for the sum of 23 PCB congeners (P = 0.37). No interstation difference was assumed, and therefore, the bluefish means for the 14 composites are given in Table 3. Bluefish muscle composites contained the highest mean PCB concentrations of the four species. The sum of 23 PCB congeners (i.e., ePCBs) ranged from 0.21 to 0.57 µg/g (ppm), with a mean of 0.37 ppm (Appendix Table C6). The PCB congener composition in bluefish composites was dominated by seven congeners: BZ #1 (monochloro), BZ #66 (tetrachloro), BZ #101 (pentachloro), BZ #118 (pentachloro), BZ #153 (hexachloro), BZ #138 (hexachloro), and BZ #180 (heptachloro). The maximum concentration of 0.57 ppm for ePCBs was found in a bluefish composite (i.e., #113; Appendix Table C6). The sum of concentrations of 18 specific PCB congeners was multiplied by 2 to generate an approximation of “Aroclor-based” total PCB data for comparison with the historical total PCB data; the approximations are shown in the second data column of Table 3 and in the last column of Appendix Tables C6-C9 (NOAA 1989; ACE-EPA 1992). The highest of these estimates was 0.9 ppm, which is below the FDA tolerance level of 2 ppm wet weight (FDA 1991).

No PCB congener had a concentration greater than 3 times the MDL in summer flounder composites. Of the six congeners (i.e., BZ #1, BZ #66, BZ #101, BZ #118, BZ #153, and BZ #138) detected in summer flounder composites, only one (i.e., BZ #1) was found at all stations.

The PCB levels in black sea bass composites were considerably lower than those found in bluefish composites. The ePCBs in black sea bass composites ranged from 0.043 to 0.14 ppm, with a mean of 0.079 ppm (Appendix Table C8). The PCB congener composition in black sea bass composites was dominated by five congeners: BZ #66, BZ #101, BZ #118, BZ #153, and BZ #138. Of the six congeners (i.e., the aforementioned five plus BZ #1) in black sea bass composites for which statistics were performed (i.e., those where the station mean concentrations were greater than 3 times the MDL), interstation differences were found for four congeners (i.e., BZ #66, BZ #101, BZ #118, and BZ #138; Appendix Table C8). Since higher PCB concentrations were found at Station SB3 for the majority of congeners and for ePCBs (P = 0.02), we consider black sea bass at the entrance to Ambrose Channel (Station SB3; Figure 1) to have higher PCB concentrations than black sea bass at the two stations farther south (Table 3).

Mean PCB levels in tautog composites were similar to those in black sea bass composites. The ePCBs in tautog composites ranged from 0.038 to 0.12 ppm, with a mean of 0.059 ppm (Appendix Table C9). The PCB congener composition in tautog composites was dominated by three congeners: BZ #1, BZ #101, and BZ #153. No interstation differences were detected for PCB levels in tautog composites.

The trend in PCB concentrations among species (Figure 4B) follows the trend in lipid content (Figure 4A). Among composite samples of bluefish, black sea bass, and tautog, PCB concentrations increased with lipid content in each species (Figure 6A). Correlation of PCBs and lipids in the pelagic bluefish (r = 0.724) was similar to the correlation for the two reef fish, black sea bass (r = 0.763) and tautog (r = 0.814) (Table 1). PCB concentrations in tautog composites were also correlated with tautog length (r = 0.695; Table 1; Figure 6B), probably because tautog length is correlated with the muscle lipid content (r = 0.559).

Organochlorine Pesticides

A significant number of station means for chlorinated pesticides were below the MDL (i.e., 29% for bluefish, 96% for summer flounder, 73% for black sea bass, and 80% for tautog). Four chlorinated pesticides were not detected in any of the 56 muscle composites (Appendix Table C5). The complete listing of the remaining 13 chlorinated pesticides is given in Appendix Tables C10-C13, and summarized in Table 3.

The pesticide composition in bluefish and black sea bass composites was dominated by total chlordanes and total DDTs. No pesticide analyte had a concentration greater than 3 times the MDL in summer flounder composites. The pesticide composition in tautog was dominated by total DDTs. No interstation differences were detected for total chlordanes or total DDTs in any fish species.

When total DDT concentrations were compared among species, the observed trend was similar to the pattern for lipids and ePCBs (i.e., bluefish > black sea bass = tautog > summer flounder; Figure 4). The DDTs were correlated with lipid content in black sea bass (r = 0.918) and tautog (r = 0.757) composites, and to a lesser degree in bluefish composites (r = 0.512) (Figure 6C). The eDDTs were correlated with tautog composite length (Figure 6B), which covaried with the lipid content (Table 1). The eDDTs correlated with ePCBs (Figure 6D) in bluefish, black sea bass, and tautog muscle composites. This relationship was stronger for black sea bass and tautog composites than for bluefish composites (Table 1).

The trend for total chlordane concentrations among species followed the same order as ePCBs, eDDTs, and lipids for bluefish, black sea bass, and summer flounder composites (Figure 4D).

Average sums of DDTs and metabolites for all composite samples (i.e., 0.014-0.16 µg/g) were below the FDA action level of 5.0 µg/g (ppm) wet weight, and average sums of chlordanes for all composite samples (i.e., 0.04-0.08 µg/g) were below the FDA action level of 0.3 µg/g (ppm) wet weight (FDA 1986, 1987).

PAHs

Nineteen of the 24 PAHs were undetected in any fish muscle composite (Appendix Table C5). The detected PAHs were not consistently found among fish species. The concentrations of the five PAHs that were detected in at least one composite are listed in Appendix Table C14. Acenaphthene was found only in bluefish composites, while benz[a]anthracene was detected only in summer flounder, black sea bass, and tautog composites. The PAH 2-methylnaphthalene was detected only in summer flounder and tautog. Summer flounder was the only species with measurable concentrations of naphthalene and 1-methylnaphthalene. The station mean for acenaphthene in bluefish was above the MDL for all three stations (Table 3; Appendix Table C14). The station mean for benz[a]anthracene was above the MDL for one black sea bass station and two tautog stations.

No apparent explanation is evident for the differing presence of these PAH compounds among the species. The absence or low concentration levels of PAHs are expected as these compounds are extensively metabolized by the fish hepatic microsomal enzymes, and the metabolites are temporarily stored in the bile until their excretion (Deshpande 1989; Varanasi et al. 1989).

2,3,7,8-Substituted PCDD and PCDF Congeners

Thirteen of the seventeen dioxin and furan congeners were not detected above the MDL in any muscle composite samples analyzed for this study (Appendix Table C5), and were not included in subsequent calculations. Complete listings of the analytical results for the four detected dioxins and furans in each composite are given in Appendix Table C15, and summarized in Table 3.

The dominant PCDD and PCDF congeners were 2,3,7,8-TCDD, octachlorodibenzo[p]dioxin, 2,3,7,8-TCDF, and 1,2,3,4,6,7,8-hepatochlorodibenzo[p]dioxin. The concentrations of 2,3,7,8-TCDD, considered the most toxic dioxin congener (EPA 1989), were below the MDL of 1.63 pg/g wet weight (pptr) in all summer flounder and black sea bass composites. Concentrations of 2,3,7,8-TCDD were below the detection limit in 10 of 14 tautog composites, and near the detection limit in the other four tautog composites (i.e., ranging from 2.36 to 3.39 pg/g wet weight). The overall tautog species mean for 2,3,7,8-TCDD was less than the MDL (Table 3).

The concentrations of 2,3,7,8-TCDD in 4 of 14 bluefish composites were below the MDL. The concentrations ranged from 1.82 to 3.76 pg/g in 9 of 10 remaining bluefish composites. The remaining bluefish composite (i.e., #113; Station BL3) contained 7.27 pg/g of 2,3,7,8-TCDD. This composite also contained the highest concentrations of ePCBs (i.e., 566 ng/g), eDDTs (i.e., 268 ng/g), echlordanes (i.e., 62.4 ng/g), and approximately twice (i.e., 13.2%) the average bluefish muscle lipid content of all composites analyzed in this survey. This composite exhibited the highest average composite weight (i.e., 3.6 kg; Appendix Table A2), and included the heaviest individual (i.e., 4.0 kg; Appendix Table A2) of all bluefish collected. The concentration of 2,3,7,8-TCDD in the other three bluefish muscle composites from Station BL3 were below the MDL of 1.63 pg/g. The station means and the species mean for bluefish muscle composites were only about 50% greater than the MDL of 1.63 pg/g (Table 3). All values for 2,3,7,8-TCDD for all composites are well below the FDA guidance level of 25 pg/g for limited consumption (Cordle 1981; Green 1981; Niemann 1986).

The furan congener 2,3,7,8-TCDF is about one-tenth as toxic as 2,3,7,8-TCDD (EPA 1989). No summer flounder composites had concentrations of 2,3,7,8-TCDF that were above the MDL. Two station means for black sea bass (i.e., Stations SB2 and SB3) were only slightly higher than the MDL, no 2,3,7,8-TCDF was found at the third (i.e., Station SB1), and the species mean was below the MDL. For bluefish and tautog, the three station means were above the MDL, with two station means for bluefish and one for tautog being greater than 3 times the MDL. For tautog, spatial differences were not significant (P = 0.13). In contrast, the mean concentration of 2,3,7,8-TCDF at bluefish Station BL3 (i.e., 7.26 pg/g) was statistically higher than those at Stations BL1 and BL2 (P = 0.02). The higher 2,3,7,8-TCDF concentrations at Station BL3 can partially be explained by the longer, heavier, and more dense bluefish at Station BL3 (Appendix Table A2).

The sum of 2,3,7,8-TCDD toxic equivalent (2,3,7,8-TCDD TE; EPA 1994) values for the three TCDD congeners and one TCDF congener detected in at least one composite ranged from a baseline of 0.90 pg/g (using one-half MDL when all four compounds were below the MDL) to 8.3 pg/g. The 13 congeners that were not detected in any of the 56 composites had a 2,3,7,8-TCDD TE value of 6.2 pg/g wet weight, at concentrations of one-half MDL.


CONCLUSIONS

  1. Total mercury levels in all fish composites were <0.11 µg/g wet weight, which is an order of magnitude below the FDA action level of 1.0 µg/g wet weight.
  2. PCB concentrations in black sea bass were higher at Station SB3 (i.e., entrance to Ambrose Channel) than at stations farther south along the New Jersey coast.
  3. PCB and organochlorine pesticide concentrations were relatively low, and were correlated with the lipid content of the muscle tissue. Bluefish, with its higher lipid content, had both the highest mean PCB and pesticide concentrations. The individual bluefish composite with the highest lipid content also exhibited the highest PCB and pesticide concentrations.
  4. The “Aroclor-based” estimate maximum of 0.9 µg/g wet weight was below the FDA tolerance level of 2.0 µg/g (ppm) for PCBs.
  5. Average sums of DDTs and metabolites for all composite samples (i.e., 0.014-0.16 µg/g) were below the FDA action level of 5.0 µg/g (ppm) wet weight.
  6. Average sums of chlordanes for all composite samples (i.e., 0.04-0.08 µg/g) were below the FDA action level of 0.3 g/g (ppm) wet weight.
  7. Consistent with findings in the scientific literature, PAHs were largely undetected.
  8. All but one of the 56 fish muscle composites analyzed in this study had concentrations <4 pg/g for 2,3,7,8-TCDD, the most toxic dioxin congener.
  9. Concentrations of 2,3,7,8-TCDD in all composite samples were below the FDA guidance level of 25 pg/g (pptr) wet weight for limited consumption.
  10. The bluefish composite with the highest PCB, organochlorine pesticide, and lipid content also had the highest 2,3,7,8-TCDD concentration (i.e., 7.3 pg/g), which was still well below the FDA guidance level of 25 pg/g (pptr) wet weight for limited consumption.

ACKNOWLEDGMENTS

The authors acknowledge the assistance of Donald Macmillan and Stuart Wilk (NMFS James J. Howard Marine Sciences Laboratory) in fish collection, and of Jeffrey Cross (NMFS James J. Howard Marine Sciences Laboratory) and Joel O’Connor and Douglas Pabst (U.S. Environmental Protection Agency - Region II) in technical review of the manuscript. This research received financial support, in part, from the U.S. Environmental Protection Agency - Region II, and the U.S. Army Corps of Engineers - New York District.


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