High resolution sedimentary records of heavy metals from the Santa Monica and San Pedro Basins, California

Volume 20/Number 4/April 1989 Koukouras, Ath., Voultsiadou-Koukoura, E., Chintiroglou, H. & Dounas, C. (1985). Benthic Bionomy of the North Aegean Sea III. A comparison of the macrobenthic animal assemblages associated with seven sponge species. Cahiers de Biologie Marine 26, 301-319. Leppiikoski, E. (1979). The use of Zoobenthos in evaluating effects of pollution in Brackish water environments. In The use of ecological variables in environmental monitoring, pp. 151-158. The National Swedish EnvironmentalProtectionBoard, ReportP.M. 1151. Mair, J. Mcd., Matheson, I. & Appelbee, J. F. (1987). Offshore Macrobenthic Recovery in the Murchison Field Following the Termination of Drill-cuttingDischarges. Mar. Pollut. Bull. 18,628-634. Margalef, R. (1968). Perspective in Ecological Theory. University of Chicago Press, Chicago. Mills, E. I. (1969). The community concept in marine zoology, with comments on continua and instability in some marine communities: a review. J. Fish. Res. Canada 26, 1415-1428. Nicolaidou, A. & Karlou, C. (1983). A benthic survey in the brackish water lagoon Mazoma of the Amvrakikos gulf. Rapp. Comm. int. Mer. Medit. 28,235-236. Nicolaidou, A., Bourgoutzani, E, Zenetos, A., Perthuisot, J. P. & Guelorget. O. (1988). Distribution of Molluscs and Polychaetes in coastal lagoons in Greece. Estuar. coast. ShelfSci. 26,337-350. Pancucci, M. A. & Zenetos, A. (1986). Gli Echinodermi del Golfo di Patrasso. Biologia Gallo-hellenica 12,189-195. Peres, J. M. & Betlan, G. (1972). Apercu sur l'Influence des Pollutions sur les Peuplements Benthiques. In Marine Pollution and Sea L i f e . Fishing News (Books) Ltd., Surrey.

Pielou, E. C. (1969). An Introduction to Mathematical Ecology. WileyInterscience, London. Scoullos, M., Bachas, L. & Dasenakis, M. (1980). Preliminary study of the pollution of Geras Gulf. Techn. Report. Lab. of Inorganic Chemistry. University of Athens. (In Greek). Shannon, C. E. & Weaver, W. (1963). The Mathematical Theory of Communication. Urbana University Press, Illinois. Sokal, R. R. & S n e a t h , P. H. A. (1963). Principles of Numerical Taxonomy.Freeman & Co., San Francisco. Theocharis, A. & Georgopoulos, D. (1984). Study of physical parameters of the gulf of Geras. 1st National Symposium on Oceanography and Fisheries. Athens, May 1984, 66-74 (In Greek). Thessalou-Legakis, M. & Zenetos, A. (1985). Autoecological studies on the Thalassinidea (Crustacea, Decapoda) of the Patras Gulf and Ionian Sea (Greece). Rapp. Comm. int. Mer. Medit. 29,309-310. Thompson, T. E., Jarman, G. M. & Zenetos, A. (1985). Infralittoral macrobenthos of the Patras Gulf and Ionian Sea: Opisthobranch Molluscs. J. Conch. 32, 71-95. Weston, D. E (1988). Macrobenthos-sediment relationships on the continental shelf off cape Hatteras, North Carolina. Cont. ShelfRes. 8,267-286. Zarkanellas, A. J. & Katoulas, M. E. (1979). The Ecology of Benthos in the Gulf of Thermaikos, Greece. I. Environmental Conditions and Benthic Biotic Indices. Mar. Ecol. 3, 21-39. Zenetos, A. & Bei, F. (1987). Preliminary studies on the community structure of the macrozoobenthos in Atalanti bay, Greece. Biologia Gallo-hellenica 13, 21-24.

Marine Pollution Bulletin, Volume 20, No. 4, pp. 181-187, 1989. Printed in Great Britain.

0025-326X/89 $3.00+0.00 © 1989 Pergamon Press plc

High Resolution Sedimentary Records of Heavy Metals from the Santa Monica and San Pedro Basins, California BRUCE

FINNEY*

and CHIH-AN

HUH

College o f Oceanography, Oregon State University, O c e a n o g r a p h y A d m i n . Bldg. 104, Corvallis, O R 97331-5503, U S A *Present address: Duke University, Marine Laboratory, Beaufort, NC 28516, USA

Box cores collected from the Santa Monica and San Pedro Basins during 1986 and 1987 were analysed for organic carbon, 2t°pb and more than 20 major and minor elements. Downcore variations in the profiles of Pb, Zn, and Cr largely reflect anthropogenic inputs, whereas profiles of Fe and Co are strongly modified by diagenesis in near-surface sediments. Both of these factors appear to influence the downcore distribution of Cu. The cores show pronounced subsurface maximum in Pb, Zn, and Cr which, based on ~t°pb dating, correspond to about 1970. Of the most likely anthropogenic sources of these metals, the time-series of emissions from the JWPCP wastewater treatment plant is most in accord with the sedimentary records, The high correlation between organic carbon and Pb, Zn, and Cr in the cores is consistent with the presence

of particulate matter of sewage origin. Thus post-1970 improvements in wastewater treatment are reflected in the near-surface decreases in heavy metals.

The Santa Monica and San Pedro Basins (Fig. 1) are the two inner basins of the Southern California Borderlands which lie directly offshore of Los Angeles. The nearly anoxic bottom water results in the absence of large burrowing organisms and therefore sediments in the deep areas of the basins are generally undisturbed by bioturbation. Sediment accumulation rates are rapid enough to allow high resolution sampling on timescales of a f e w y e a r s o r less. W i t h i n 4 0 k m o f t h e d e e p 181

Marine Pollution Bulletin 410'

20'

[

11~*W

40'

20' I

MoN,cA BAS,.

PEDRO

40"

20*

119°W

40"

20'

Fig. l Core locations and bathymetry of the Santa Monica and San Pedro Basins. Locations of Hyperion and JWPCP outfalls are also shown.

portions of these basins are outfalls of the two largest wastewater treatment plants in the Southern California Bight, the Joint Water Pollution Control Project (JWPCP) plant of the Los Angeles County Sanitation District and the Hyperion plant of the City of Los Angeles. Previous studies of sediments in the borderlands have demonstrated the strong impact of human activities on the sedimentary record (e.g., Chow et al., 1973; Bruland et al., 1974; Bertine & Goldberg, 1977; Galloway, 1979; Ng & Patterson, 1982, Stull et al., 1986). Thus the location and sedimentary environments of these basins are ideal for studies of the history and fate of metals introduced into the southern California coastal zone. The pioneeringworkofBrulandetal.(1974)wasthe last to report a fairly complete chemical analysis on cores (recovered in 1971) from these basins. This work established the presence of strong anthropogenic signatures in deep basin sediments for metals such as Pb, Zn, Cr, Cu and V. In the time following this study, there have been significant improvements in wastewater treatment and pollution control. Therefore, a fresh assessment of the sediments from these areas may lead to a better understanding of the sources, transport pathways andfatesofanthropogenicmaterials, As part of the DOE CaBS (California Basin Study) programme, we have studied box cores from the Santa Monica and San Pedro Basins collected during cruises in 1986 and 1987. One of our goals is to construct high resolution records of anthropogenic metal deposition through careful sampling and age-dating, and by determining baseline pollution-flee metal concentrations, The sources of metals of anthropogenic origin may be inferred by comparing such records to historical records of wastewater emission, runoff, atmospheric 182

input and other important sources. In addition, the fate and transformation of metals during transport and sedimentation may be evaluated by determining the composition and flux of the anthropogenic component buried in the sediment. Materials and M e t h o d s We report here the results of analysis of box cores recovered from the deep anoxic zone of each basin. Core LBC1 from the Santa Monica Basin was collected during the Basin-I (May 1986) cruise, and core BC9 from the San Pedro Basin was collected during the CaBS-V (April 1987) cruise (Fig. 1). Both cores were determined to be recovered with an undisturbed sediment-water interface. Upon recovery subcores were immediately sectioned at 0.25-0.50 cm intervals, and the subsamples were frozen until analysis in the laboratory. Samples were dried and ground to less than 400 mesh using a mortar and pestle. The concentrations of major and minor elements were determined by a Phillips PW 1600 simultaneous X-ray fluorescence (XRF) spectrometer on powdered discs pressed under a force of 5 t. The machine was calibrated with a large set of USGS, NBS, international and in house standards. USGS marine sediment standard MAG-1, with a matrix similar to our samples, was used as a reference standard. For the elements discussed in this paper, our results are within 12% of reported values (Gladney & Goode, 1981) for this standard. Analytical precision, estimated by replicate analysis of MAG-1, is better than 2% for A1 and Fe, 3% for Zn and Cr, 5% for Cu, and 10% for Ba and Pb. Organic carbon was measured using the LECO wet oxidation technique of Weliky et al. (1983). 21°Pb was determined via 21°Po by

Volume 20/Number 4/April 1989 Pb-210(excess)/Al

Pb-210(excess)/Al .1 0.0

1

10

100

10

.........................

0.0

100

..................

0.2"

i

--

0.5"

~ 0.4"

~"

-'. ~0.6" 1.0"

~.

1.0 1.5 Basin-I L B C 1

V BC9

1.2 S = 13.6 mg/cm2/yr

R = 0.99

S = 13.4 mg/cm2/yr

R = 1.0

Fig. 2 The ratio of excess 21°Pb to AI plottted against cumulative

sediment dry mass (on a salt-free basis) for the Basin-I LBC1 and CaBS-V BC9 cores. Excess 21°Pb has been normalized to Al, which is supplied from crustal rock sources (Bruland et al., 1974), to avoid bias caused by variable amounts of authigenic Fe-oxyhydroxides and calcium carbonate. The data in BC9 have been corrected by excluding a turbidite as discussed in the text.

cx-spectrometry, which involves auto-deposition of Po on silver discs, with 2°8po (NBS SRM-4327) used as yield monitor (Huh et al., 1987). All data were corrected for salt content based on XRF-determined CI content,

Results and Discussion Chronologies were established for each core from profiles of excess 2t°pb. The 2t°pb based accumulation rate for LBC1 is 13.6 mg cm -2 yr -~ (Fig. 2). In BC9, the presence of a turbidite at 0.5-1.75 cm depth was revealed by anomalous water content, 2t°pb, and elemental data. In determining the sediment accumulation rate for this core, the interval was excluded from the profile of excess 2~°pb as the deposition of this unit was probably very rapid. This correction results in an excellent fit to the 2t°pb data (Fig. 2) and indicates that the sediment accumulation rate for this core is 13.4 mg cm -2 yr-~. In the following discussion, we have corrected the elemental profiles for this core by excluding the turbidite section. Sediment mixing in the anoxic parts of these basins is relatively low and decreases by three orders of magnitude in the top 3 cm (Huh et al., 1987). Therefore, the sedimentary records should notbesignificantlyaltered, The heavy metals Pb, Zn, and Cr display subsurface maxima at depths ranging from about 1 to 2 cm in cores from both basins (Fig. 3), which correspond to the time interval 1960-1970. The onset of rapid increases in these metals occurred during the 1930s. Previous studies on cores from these basins have determined that the near surface enrichments in these metals resulted from anthropogenic inputs (Chow et al., 1973; Bruland et al., 1974; Ng & Patterson, 1982; Finney & Huh, 1989). The fraction of these metals that is supplied by

anthropogenic sources may be estimated by determining baseline pollution-free metal concentrations in the cores. We have defined this background component in each core from the composition at depth where the metal to A1 ratio reaches a constant level (Fig. 3). The anthropogenic component is chlculated by subtracting the background fraction from the measured value. Estimated fluxes of anthropogenic Pb, Zn, and Cr to each core are listed in Table 1. The anthropogenic fluxes in BC9 are about 30% less than those in LBC1. These fluxes have decreased dramatically since 1970 in both cores. The most important anthropogenic sources of these metals are runoff, atmospheric input and sewage emissions (Bruland et al., 1974; Galloway, 1979). Timeseries of emissions of Pb, Zn, and Cr from the three wastewater treatment plants adjacent to the basins are depicted in Fig. 4. JWPCP inputs dominated the mass flux of these metals to the Southern California Bight from the late 1930s to the early 1980s. The historical records observed in the cores (Fig. 3) match the emission trends from JWPCP quite closely. Studies of currents in the region (Jackson etal., 1988) also suggest that emissions from JWPCP are the most likley to impact the study areas. Materials from JWPCP would enter the narrow Palos Verdes Shelf where the TABLE 1 Anthropogenic Fluxes (p.g cm -2 yr -~) of Pb, Zn, and Cr in the Santa Monica and San Pedro Cores. Santa Monica Basin, LBC1 San Pedro Basin, BC9

Element PeakFlux Pb

Zn Cr

0.52

0.77 1.46

PresentFlux* Peakflux

PresentFlux*

0.21

0.10

0.00 0.48

0.37

0.47 1.10

0.00 0.32 *Core-top sample (covering approximately 1983-1986 in LBCI and 1983-1987 in BC9). 183

Marine Pollution Bulletin

1980

1980 -

1970

1970 -

1960

1960 -

1950

1950 -

YEAR

YEAR 1940

1940 -

1930

%~

1920 -

N~B

•

LBC1

1920 -

•

LBC1

1910 "

~

•

BC9

1910 -

•

BC9

1900

. .

1930 -

r , • . . , . • . , . • 6 8

2

Pb, ppm/AI,

1900 100

1;0"

%

2;0"

2'50" 3;0"

Ba, ppm/AI,

1980 -

1980

1970 -

1970

1960

1960

•

1950

3'50

%

f

1950

YEAR

YEAR 1940

1940

1930

1930

1920

LBC 1

1920 •

•

LBC 1

1910

BC9

1910 •

,¢

BC9

1900

........ 5

20

, .... 25

Zn, ppm/AI,

1980

, .... 30

~ 35

1900

....

, .... 1.0

0.5

%

, .... 1.5

, 2.0

Fe, % / A I ,

-

1980 t / 1970 1 / 1960 t

1970 ' 1960' 1950 '

1950 t

YEAR

YEAR 1940 '

1940 1

1930 '

1930

1920 ' '~ 1910 " 1900

1920 t t 1910

LBcB~91

• 5

20 Cr,

25

30

19001 4

35

ppm/AI, %

l A

5

6

, 8

7

•

LBCI BC9 ,~ 9

Cu, ppm/AI, %

1,8o

1970 •

(

1960' 1950 • YEAR 1940 '

~

i

1930 ' LBC1 BC9

1920 '

Fig. 3 Downcore distributions of Pb/AI, Zn/A1, Cr/AI, Ba/Al, Fe/AI, Cu/AI, and AI since about 1900 in cores Basin-I LBC1 and CaBS-V BC9. Ages of the sediment horizons are based on the 2]°Pb-based chronology. As discussed in Fig. 2, the data have been normalized to Al. Absolute concentration ranges (on a salt-free basis) are 9-53 ppm for Pb, 108-189 ppm for Zn, 113-218 ppm for Cr, 650-2087 ppm for Ba, 4.35-9.68% for Fe, and 32-43 ppm for Cu. Emissions from JWPCP began in 1937 and reached maximum rates around 1970. 184

1910-

1900

• 6

7 AL, %

;

Volume 2 0 / N u m b e r 4/April 1989

prevailing northwesterly currents are likely to result in transport across the Santa Monica Basin. In contrast, currents in the vicinity of the Hyperion outfall suggest direct transportation of materials from the Santa Monica Shelf to the basin is uncommon. Such material would likely enter the basin only after circulating southeastward along the shelf and joining the northwesterly slope currents. Transport of materials from JWPCP into the San Pedro Basin may occur during pulses of equatorward flow (which have been observed primarily during the spring), or from transport down Redondo Canyon where particles may be directed into either basin (Malouta et al., 1981). Both cores show downcore maxima in organic carbon that correspond to the heavy metal peaks (Figs 3, 5). The strong correlation between the metals and organic carbon may result in part from the presence of sewage particles, which are very enriched in organic carbon, Pb, Zn, and Cr (Bruland et al., 1974; Galloway, 1979; Katz & Kaplan, 1981). This is consistent with the time-series of input of organic-rich suspended solids from JWPCP (Fig. 4). Thus the organic carbon profiles lend further support to the hypothesis that the chemical composition of sediments is influenced by input of wastewater particulates. Fluxes of these metals from runoff from the Los Angeles River are estimated in Table 2. The Los Angeles River supplies - 8 0 % of the total runoff to the basins (SCCWRP, 1986). The estimated fluxes of these metals are closely related to rainfall, and temporal variations in these fluxes do not follow the sedimentary profiles (Fig. 3). In addition, fluxes from 5WPCP during the 1970s appear to have been much greater than runoff fluxes (Fig. 4 and Table 2), except perhaps for Pb and Zn during the extremely wet winter of 1979/80. •

•

TABLE2 Estimated Runoff Fluxes (M t yr -~) from the Los Angeles River*

Year 1971/72 1979/80

Pb 64 108

Zn 68 646

Cr 6 67

Suspended

1985/86

32

81

11

116 000

*From SCCWRP (1986)

With continued reductions in wastewater emissions, the relative importance of runoff may increase. Atmospheric inputs are likely to be most important for Pb, followed by Zn (Bruland et al., 1974; Ng & Patterson, 1982; Jickells et al., 1987). Anthropogenic Cr does not appear to have significant atmospheric sources to the Southern California Bight (Bruland et al., 1974). The input trend of atmospheric Pb may be estimated from U.S. gasoline consumption records (Shen & Boyle, 1987). The records are similar to the sedimentary profiles with both maxima occuring around 1970. Ng & Patterson (1982) estimate that ~ to 3 of the anthropogenic Pb in the deep sediments of these basins is of sewage origin. Thus atmospheric input may provide a significant but secondary source of anthropogenic Pb and Zn. The subsurface peaks in the Ba profiles correspond to about 1960 in both cores (Fig. 3). This chronology is compatible with Ba profiles reported by Ng & Patterson (1982) for cores from the Santa Monica and San Pedro Basins. The Ba enrichment is most likely due to dumping of barite-rich oil drilling muds (Chow et al., 1978) in the San Pedro Basin (D. Gorsline, personal communication, 1988). Subsequent transport of this material into the Santa Monica Basin may occur over the deep sill between the two basins (Nelson et al., 1987). 150 "

JWPCP

~' . 1 5 0 0 0 0 "

Solids

14000 1 350 000

Orange Co.

•

JWPCP

•

Orange C o

g .~

= g.

10oo00

~ 1oo--~

5oo00

50"

0 . . . . 1970

i . . . . 1975 YEAR

i . . . . 1980

, , 1985

500"

JWPCP Hyperion

400 '

Orange CO.

-.~ 3o0

0 . . . . 1970

i . . . . 1980

, • 1985

1500

• ~ ~

JWPCP

Hyperion Orange Co

p.

200.

J . . . . 1975 YEAR

£

tooo

500

lOOo

197o

.

.

.

.

,

.

.

.

.

,

1975

198o

.

.

.

.

,

1985

.

o

197o

.

.

.

.

,

YEAR Fig.

.

.

.

.

1975

,

198o

.

.

.

.

,

.

1985

YEAR 4 Time-series of emissions from the wastewater treatment plants adjacent to the Santa Monica and San Pedro Basins (from SCCRWP reports, 1974; 1975; 1976; 1977; 1978; 1980; 1982; 1986).

185

Marine Pollution Bulletin • 19801970 ~96o 19s0 YEAR 1940 193o 192o 1910 1900

LBCl Bc9 . . . . 4

s

Organic Carbon, % Fig. 5 Organic carbon profiles for the two cores since 1 9 0 0 . T h e surficial sediment in both cores is yellow-brown in colour, in contrast to the green sediment below. This layer is strongly enriched in Fe, Co, P, and Cu (Fig. 3;

Finney & Huh, 1989). The Fe enrichment most likely results from reduction of Fe in the sediments during the oxidation of organic matter (Froelich et al., 1977), followed by upward diffusion and precipitation as a m o r p h o u s oxyhydroxides near the sediment-water interface. This process is compatible with pore water analysis which shows dissolved Fe concentrations increasing from seawater values at the sediment-water interface to a maxima at 1 - 2 cm depth (R. Jahnke, written c o m m u n i c a t i o n , 1988), and the colour change observed in the sediments (Lyle, 1983). T h e surface enrichments in P, Co, and Cu also a p p e a r to be controlled by diagenetic process in the sediments. During early diagenesis, P, Cu, and Co are released near the sediment-water interface (Klinkhammer, 1980; Fischer et al., 1986; J o h n s o n e t al., 1988; R. Jahnke, personal c o m m u n i c a t i o n , 1988) where they are likely a d s o r b e d to the Fe-oxyhydroxides. The affinity of P, Cu, and C o with Fe-oxyhydroxides has been noted by other workers (Balistrieri & Murray, 1982; D y m o n d et al., 1984). T h e Cu profile in the Santa M o n i c a Basin also shows a subsurface peak associated with the Pb, Zn, and Cr maxima (Fig. 3). While anthropogenic sources may be important in supplying C u to the basins (Bruland et al., 1974), some Cu is clearly associated with the Fe-rich phase. Because C u profiles are strongly influenced by diagenesis, they do not reflect the history of anthropogenic input (Finney & H u h , 1989).

Conclusions D o w n c o r e variations in Pb, Zn, and Cr in the Santa M o n i c a and San P e d r o Basins a p p e a r to result largely

from changes in the flux of anthropogenic material. The profiles indicate that pollution levels in sediments have decreased dramatically over the past 1 5 - 2 0 years (Table 1). T h e present day flux of anthropogenic Pb and Cr deposited in these sediments is about one third or less of the flux during peak contamination a r o u n d 1970. Z n a b u n d a n c e s in near-surface sediments from both basins are similar to baseline levels deposited before about 1930. T h e most likely sources of these metals are sewage outfalls, runoff and atmospheric 186

input. Sedimentary time-series of these metals are m o s t similar to the emission history of the J W P C P wastewater treatment plant. This suggests that sewage material has been the d o m i n a n t source of these metals to the inner basins. T h e organic c a r b o n profiles in these cores are highly correlated to the metal profiles, and support the hypothesis that the sediments receive an input of sewage particulates. The sediments in these environments a p p e a r to respond quickly (within a few years) to changes in pollution control. Diagenetic processes associated with the b r e a k d o w n of organic c a r b o n also influence sedimentary metal profiles. Reduction of Fe in the sediments results in a near-surface enrichment of authigenic Fe-oxyhydroxides. D o w n c o r e profiles of metals such as C o and C u are strongly influenced by this process.

We would like to thank R. Jahnke, A. Soutar, J. Singleton and the Captain and Crew of the R. V. New Horizon for help during coring operations, and S. Niemnil, A. Ungerer, G. Campi and J. Robbins for laboratory assistance. This research was supported by Department of Energy GrantNo. DE-FGO5-85ER60340.

Balistrieri, L. S. & Murray, J. W. (1982). The adsorption of Cu, Pb, Zn and Cd on goethite from major ion seawater. Geochim. Cosmochim. Acta46, 1253-1265. Bertine, K. S. & Goldberg, E. D. (1977). History of heavy metal pollution in southern California coastal zone-reprise. Environ. Sci. Technol. 11.297-299. Bruland, K. W., Bertine, K., Koide, M. & Goldberg, E. D. (1974). History of metal pollution in southern California coastal zone. Environ. Sci. Technol. 8,425-432. Chow, T. J., Bruland, K. W., Bertine, K., Soutar, A., Koide, M. & Goldberg, E. D. (1973). Lead pollution: records in southern Californiacoastal sediments. Science 181,551-552. Chow, T. J., Earl, J. L., Reed, J. H., Hansen, N. & Orphan, J. (1978). Bariumcontent of marine sediments near drilling sites: A potential pollutant indicator. Mar. Pollut. Bull. 9, 97-99. Finney,B. P. & Huh, C. A. (1989). History of metal pollution in the Southern California Bight: An update• Environ. Sci. Technol. (in press). Fischer, K., Dymond, J., Lyle, M., Soutar, A. & Rau, S. (1986). The benthic cycle of copper: evidence from sediment trap experiments in the eastern tropical North Pacific Ocean• Geochim. Cosmochim. ActaSO, 1535-1543. Froelich,P. N., Klinkhammer, G. P., Bender, M. L., Luedtke, N. A., Heath, G. R., Cullen, D., Dauphin, P., Hammond, D., Hartman, B. & Maynard, V. (1977). Early oxidation of organic matter in pelagic sedimentsof the eastern equatorial Atlantic: Suboxic diagenesis. Geochim. Cosmochim. Acta43, 1075-1090. Galloway,J. N. (1979). Alteration of trace metal geochemical cycles due to the marine discharge of wastewater. Geochim Cosmochim. Acta 43, 207-218.

Gladney, E. S. & Goode, W. E. (1981). Elemental concentration of eight United States Geological Survey rock standards--A review. Geostandards Newsletter 5, 31-64. Huh, C. A., Zahnle, D. L., Small, L. F. & Noshkin, V. E. (1987). Budgets and behaviors of uranium and thorium series isotopes in santa Monica Basin sediments. Geochim Cosrnochim. Acta 51, 1743-1754. Jackson, G. A., Azure, F., Carlucci, A. F., Eppley, R. W., Finney, B., Gorsline,D. S., Hickey, B., Huh, C. A., Jahnke, R. A., Kaplan, I. R., Landry,M. R., Small, L. F., Venkatesan, M. I., Williams, P. M. & Wong, K. M. (1988). Elemental Cycling and fluxes off the coast of southern California. (Submitted to EOS). Jickells, T. D., Church, T. M. & Deuser, W. G. (1987). A comparison of atmospheric inputs and deep-ocean particle fluxes for the Sargasso Sea. GlobalBiogeochemicalCyclesl, 117-130. Johnson, K. S., Stout, P. M., Berelson, W. H. & Sakamoto-Arnold, C. M. (1988). Cobalt and copper distributions in the waters of the Santa MonicaBasin, California. Nature332,527-530.

Katz, A. & Kaplan, 1. R. (1981). Heavy metals behavior in coastal sedimentsof southern California: a critical review and synthesis. Marine Chem. 10,261-299.

Volume 20/Number 4/April 1989 Klinkhammer, G. P. (1980). Early diagenesis in sediments from the eastern equatorial Pacific, II. Pore water metal results. Earth Planet Sci. Lett. 49, 81-101. Lyle. M. (1983). The brown-green color transition in marine sediments: a marker of the Fe(IIl)-Fe(II) redox boundary. Limnol. Oceanogr. 28, 1026-1033. Malouta, D. N., Gorsline, D. S. & Thornton, S. E. (1981). Processes and rates of recent (Holocene) basin filling in an active transform margin: Santa Monica Basin, California Continental Borderland. Jour. Sed. Petrology S l, 1077-1095. Nelson, J. R., Beers, J. R., Eppley, R. W., Jackson, G. A., McCarthy, J.J. & Soutar, A. (1987). A particle flux study in the Santa Monica-San Pedro Basin off Los Angeles: particle flux, primary productivity, and transmissometer study. Cont. ShelfRes. 7,307-328. Ng, A. & Patterson, C. C. (1982). Changes of lead and barium with time in California off-shore basin sediments. Geochim. Cosrnochim. Acta 46, 2307-232I. SCCWRP (1974). Annual Report. Southern California Coastal Water Research Project, E1Segundo, California. SCCWRP (1975). Annual Report, Southern California Coastal Water Research Project, El Segundo, California.

SCCWRP (1976). Annual Report, Southern California Coastal Water Research Project, El Segundo, California. SCCWRP (1977). Annual Report. Southern California Coastal Water Research Project, El Segundo, California. SCCWRP (1978). Annual Report. W. Bascom, Ed. Southern California Coastal Water Research Project, El Segundo, California. SCCWRP (1980). Biennial Report. W. Bascom, Ed. Southern California Coastal Water Research Project, Long Beach, California. SCCWRP (1982). Biennial Report. W. Bascom, Ed. Southern California Coastal Water Research Project, Long Beach, California. SCCWRP (1986). Annual Report. W. Bascom, Ed. Southern California Coastal Water Research Project, Long Beach, California. Shen, G. T. & Boyle, E. A. (1987). Lead in corals: reconstruction of historical industrial fluxes to the surface ocean. Earth Planet. Sci. Lett. 82,289-304. Stull, J. K., Baird, R. B. & Heesen, T. C. (1986). Marine sediment core profiles of trace constituents offshore of a deep wastewater outfall. J. WaterPollut. ControlFed. 58,985-991. Weliky, K., Suess, E., Ungerer, C. A. & Fischer, K. (1983). Problems with accurate carbon measurements in marine sediments and particulate matter in seawater: A new approach. LimnoZ Oceat, ogr 28, 1252-1259.

Edited by E. I. Hamilton

Marine fbllution Bulletin, Volume 20, No. 4, pp. 187-189, 1989, Printed in Great Britain.

The objective of BASELINE is to publish short communications for the concentration and distribution of elements and compounds in the marine environment. Only those papers which clearly identify the quality of the data will be considered for publication. Contributors to Baseline should refer to 'Baseline--A Record of Contamination Levels' (Mar. Pollut. Bull. 13,217-218).

Metals in Northeast Pacific Coastal Sediments and Fish, Shrimp, and Prawn Tissues Sediment and tissues of epibenthos were collected in unpolluted coastal and offshore, continental shelf areas to provide baseline data for comparison with similar data from polluted environments. The objectives were to measure natural variation of trace metals along the British Columbia coast and to determine if metal levels in tissues were related to metal levels in sediments under natural conditions, Figure 1 shown the survey locations: Hecate Strait, Surf Inlet, Laredo Sound, Quatsino Sound, and Barkley Sound. The top 2.0 cm of surface sediment was sampled from a Smith-Maclntyre grab. Biota were collected with a small otter trawl. All species caught were counted, weighed, and measured. Muscle, liver or hepatopancreas and gill tissues were dissected using a stainless steel scalpel. Samples of both sediments and biota were frozen on board ship for later chemical analysis,

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Sediment samples were freeze-dried and sieved (100 mesh nylon sieve). They were digested in 4:1 nitrichydrochloric acid and analysed on an Inductively Coupled Argon Plasma (ICAP) Optical Emission Spectrometer. Low-level cadmium and lead levels were measured with an Atomic Absorption Spectrophotometer (A_AS) with a graphite tube furnace. Biota were thawed, blended, freeze-dried, oxidized in a low temperature asher, digested in warm nitric acid, and analysed on the ICAP. Tissues with cadmium and lead below ICAP detection limits were further analysed by A_AS. Mercury was analysed by 'cold vapour' AAS after being oxidized with peroxide and diluted with potassium permanganate. Standard reference materials lobster tort (NRC), oyster tissue (NBS), bovine liver (NBS), and BCSS marine sediment (NRC) or MESS marine sediment (NRC) were analysed with each batch. All results for data given here were within 10% of certified values. For biota, only trace metal levels in muscle tissues of commercial species are reported. Also, to provide an adequate measure of variability, only species represented by at least three specimens per trawl are reported. Results not reported here and more detailed information on methods are given by Harding et al. (1985) and Harding & Thomas (1987). This includes trawl catch statistics, full ICAP scan results (A1, As, Ba, Be, Ca, Co, Fe, Mg, Mn, Mo, Na, Ni, P, Si, Sn, Sr, Ti, V), trace metal levels in liver or hepatopancreas and gill tissues, and analytical results for non-commercial species. Table 1 gives the trace metal levels in sediments. Cadmium, chromium, copper, and mercury were significantly correlated with aluminium, representing the clay 187