8 
TABLE !11—DDT AND PCB CONCENTRATIONS IN FISH 
Concentration t 
Region and material PCB DOT 
Se a Ee ee ae ee See ee Pe ASE) ae ae eee © 1-10 0.6-3 
DIVET ee ee tae meme cle PRS DEES Pee een eae eae, Vranas * 1, 000-6, 000 95-4800 
Nidwatey fisthandicrustaceat es tot. 52 bY gress ody PO ewig pe. eee ce 8-59 S 
Open South Atlantic: Midwater fish and crustacea___.__---_---_-----_--------------- 2-14 Tes 
Denmark Strait: Groundfish: 
OTE Se NS Be Te Eee oe See eae ares ae oot ee ee eee eer 2-360 3-30 
[ity hae RS 5 lc ang Sone ee ee PE Se Yee go td ok eg Le Rh ea BY 300-1, 000 9-260 
Northwest Atlantic shefl: Groundfish: 
INISCIO ee 22 Ere obec tee Nee Sn eh ee ee a ah 37-187 3-74 
ATE ROE ER PES EET EO ae SE LL Ia 2 SESE eS 1870-21, 800 390-2, 680 
GulfiofiMexicosWhole-fiSh @fniselp<- = 3s eee ee ee Pe <1-530 1-150 
Northeast Pacific: 
Eqpiaipiidss <)-74442.2-320 Pe Sot ced fel re. vege shes pe ed 9.2 (mean) 2.7 (mean): 
PirCshnimpcs tet we ee ce ae ee ey Soka ee eh ea 23 (mean) 2.5 (mean) 
Frathisfatst 220-20 CORR bes C5 00 ENS PEO A we es a aed «2 23 (mean) 10.8 (mean): 
Scottish west coast: 
RSH MMUSCIG oS ee ea ee eee Oe eet eee es eae ee <100-1, 500 <30-480 
Fashrliversfiieert sf geet pig): everson ce (cy oe aye Pct ee eI 200-42, 600 70-5, 800 
Baltic Sea: 
Herringee £ otek sist 22 pce Eee EE esse a 150-1, 500 100-1, 500 
mY Cis ERE, Eee ee See Pe ee Py ee oe ee Oe eee 16-180 9-340 
1 Expressed in micrograms/kilogram (ppb) wet weight; DDT values include all metabolites. 
Source: IDOE, Op. cit. p. 14. 
Municipal wastes—The most common method of disposing of 
municipal waste is to release it into a convenient body of water. Since 
the majority of the cities in the world are situated near the coast or on 
inland rivers and lakes, the resultant release of municipal sewage has a 
direct effect on the world’s oceans. With increasing amounts of sewage 
being generated, natural purification processes are being overwhelmed 
and many sewage treatment plants are operating at capacity. Even 
sewage treatment plants do not remove everything, generally leaving’ 
nitrogen and phosphorus compounds and some oxidizable organic 
matter. In some cases sewage is discharged directly into the sea either 
by barge, as does New York City, or from offshore pipes, as does the 
Hyperian plant in Los Angeles. 
The first negative effect of disposal of sewage and sludge into sea- 
water is in decreasing the light penetration into the water, leading to a 
decrease in photosynthesis and plant product. A second effect is bio- 
degradation of organic matter resulting in a reduction of the available 
oxygen in the water. After the available dissolved oxygen is depleted, 
further biodegradation can continue by reducing nitrates and sulfates, 
producing, among other things, hydrogen sulfide which is poisonous 
to many life forms. Another consequence of biodegradation is the 
phosphorus and nitrogen compounds remaining after degradation 
of organic material. Added to the phosphorus and nitrogen entering 
directly from sewage, these plant fertilizers can induce excessive 
growth of phytoplankton in the surface layers of the ocean. This 
plant growth may increase to such an extent that the photosynthetic 
activity in the water masses below is reduced to zero. One description 
of such conditions in a Dutch oyster district reads: ‘‘At some distance 
from the harbor the water had a greenish color; large amounts of 
flagellates predominated. Oyster larvae carried to this section failed 
to settle. They developed symptoms of ill health, lost their attractive 
