14 
One method of evaluating the rate of heavy metal pollution of the 
oceans by man’s activities is by comparison with natural geological 
rates of mobilization. Table VIII lists data for 12 elements and the: 
ratio of the man-induced rate to the geologic rate. Although the: 
absolute magnitudes of the mobilization rates differ greatly among 
the elements, the ratio highlights the significance of man’s impinge- 
ment on the oceans. For example, man mines 110 times the amount of 
tin that would be cycled naturally, but Table VI indicates only 16. 
percent of the amount mined reaches the oceans annually. 
TABLE VIIIl.—RANK ORDER RATES OF MOBILIZATION OF MATERIALS 
Geological Man-induced 
rate,G (108 —srate, M (103 
metric tons) metric tons) 
Element per year per year Ratio M/G 
MU stad es Se 2 i a hh 22k ee 1.5 166 110.0 
PHOSDHONIS: ees eee ee ea a a ae ce 180.0 6, 500 36.0 
Antimony_______- iz 40 31.0 
Lead____ 180.0 2, 330 13.0 
iron___ 25, 000. 0 319, 000 13.0 
Copper-___ 375.0 4, 460 12.0 
ince 370.0 3, 930 11.0 
Molybdenum. 13.0 57 4.4 
Manganese___ 440.0 1, 600 3.6 
ercury_.._.-- 3.0 7 23 
SVE eee 5.0 7 1.4 
Nickel: 222-2 =2-2- ee ee ee ee 300. 0 358 1.1 
Sources: Geologic rate—Bowen, H. J. M., ‘‘Trace Elements in Biochemistry,’’ New York, Academic Press, 1966: 241 p.. 
eapenauced rate—United Nations, ‘‘Statistical Yearbook, 1967,’’ New York; Statistical Office of the United Nations, 1968: 
p. 
TABLE 1X.—CONCENTRATION FACTORS FOR THE TRACE ELEMENT COMPOSITION OF SHELLFISH 
COMPARED WITH THE MARINE ENVIRONMENT 
Enrichment factors 
Element Scallop Oyster Mussel? 
SHIVER.CAG)L = sees Se = ek tite i oS ee oe eee ee ee 2, 300 18, 700 330 
CEU LUT NCE) oe ee kn a es a Se A esp 2, 260, 000 318, 000 100, 000 
Chron ne 2 ee ee ee fe ORE ey oe 200, 000 60, 000 320, 000 
Gon pence) =. 2a 5 ea oh hk CN en 3, 000 13, 700 3, 000: 
Iron Che) Merce Stee te sa RE a ee gh 291, 500 68, 200 196, 000° 
Mancarreseici n)saat 22 ee ye Ee Ss ee 55, 500 4, 000 13, 500 
Mor vbcerntirnt (MG) epee eee a 8 90 30 60 
TICKENC NE) S52 key COREL SRE I: OR ee TO 12, 000 4, 000 14, 000: 
Pea RD) uaa Sse tans seei ae AWE hae. OW GeO Bee 5, 300 3, 000 4, 000- 
VETTE CTT (01) Ri ROE Se TD, J EAR, RCO S OERESS 4, 500 1, 500 2, 500° 
PAT SY 07d 1) es ene SP Mt RES ee (SRR RIE |’ eS 8G 28, 000 110, 300 9, 100° 
Source: Brooks, R. R. and M. G. Rumsby. The biogeochemistry of trace element uptake by New Zealand bivalves. “‘Lim-- 
nology and Oceanography,” vol. 10, 1965: 521-527. 
The heavy-metals uptake and contamination of marine organisms 
has been mentioned. A useful index of the potential hazard of a pol- 
lutant is the concentration factor in the food chain. Table TX lists 
the enrichment factors of several trace elements in shellfish. Metals are- 
nondegradable and even when discharged into the ocean in small 
quantities can be accumulated to an alarming and lethal extent by 
certain species. Land pollution creates sea pollution and the time 
required for passage of metals from seawater to marine organisms to- 
man often can be brief. 
Petroleum.—One of the most visible and highly publicized pollu- 
tants in the world’s oceans is petroleum. Thousands of minor, and 
