The types of research cover various fields of 

 biology, microbiology, experimental physiology, 

 biochemistry, chemistry, biophysics, molecular 

 biology, radiobiology, fishery biology, fishery man- 

 agement, and industrial research. Consequently, 

 the effluents discharged into estuarine and coastal 

 waters vary from ordinary household sewage to 

 mixtures containing an array of organic and inor- 

 ganic compounds, drugs, and radioactive isotopes. 

 The composition of these effluents cannot be pre- 

 dicted with certainty because the type of research 

 varies gready from year to year. The laboratory 

 effluent is separated usually from the sea water 

 system, which as a rule has independent plumbing, 

 but is mixed with the domestic sewage and fre- 

 quendy is discharged into natural waters. When 

 many scientific establishments are concentrated in 

 a relatively small area, the situation may become 

 serious. Chlorinated raw sewage entering the 

 harbor a short distance from shore may be caught 

 by a tidal eddy and for several hours circulate 

 close to the sea water intakes of several labora- 

 tories before it is carried out by tides. 



To maintain desired water quality requirements 

 for aquatic life, it is necessary to separate labora- 

 tory effluents from domestic sewage and provide 

 treatment that renders them harmless to aquatic 

 biota. Under no conditions should highly toxic 

 chemical compounds or drugs be permitted to be 

 discharged into natural waters if toxic concentra- 

 tions of them can be detected by chemical and 

 physical methods. 



Many marine laboratories are utilizing exotic 

 and endemic microorganisms, some pathogenic, 

 in research. Extreme caution must be exercised to 

 prevent contamination of water by introduction 

 of biological materials which can harm marine 

 organisms. 



Laboratory administrators should be responsible 

 for the periodical examination of the toxicity of 

 the effluent discharged into natural waters by their 

 institutions. 



Recommendation: (1) Allowable concentrations of 

 metals, ammonia, cyanides, and sulfides should be 

 determined by the use of 96-hour TLm values and 

 appropriate application factors. Preferably, the TLm 

 values should be determined by flow-through bioassays 

 in which environmental factors are maintained at levels 

 under which these materials are most toxic. Tests 

 should utilize the most sensitive life stage of species of 

 ecological or economic importance in the area. Tenta- 

 tively, it is suggested that application factors should 

 be Hoo for pesticides and metals, Yzo for ammonia, 

 lAo for cyanide, and %o for sulfides. 



(2) There is evidence that fluorides are accumula- 

 tive in organisms. It is tentatively suggested that 

 allowable levels should not exceed those for drinking 

 water. 



(3) The further dilution of wastes in marine waters 

 suggests that the adoption of criteria established for 

 detergents and surfactants in fresh water also will 

 protect adequately biota in the marine environment. 



(4) Bacteriological criteria of estuarine waters 

 ultilized for shellfish cultivation and harvesting should 

 conform with the standards as described in the Na- 

 tional Shellfish Sanitation Program Manual of Opera- 

 tion. These standards provide that: 



(a) Examinations shall be conducted in accord- 

 ance with the American Public Health Association 

 recommended procedures for the examination of 

 sea water and shellfish. 



(b) There shall be no direct discharges of un- 

 treated sewage. 



(c) Samples of water for bacteriological examina- 

 tion to be collected under those conditions of time 

 and tide which produce maximum concentration of 

 bacteria. 



(d) The coliform median MPN of the water does 

 not exceed 70/100 ml, and not more than 10 percent 

 of the samples ordinarily exceed an MPN of 230/ 

 100 ml for a 5-tube decimal dilution test (or 330/ 

 100 ml where the 3-tube decimal dilution test is 

 used) in those portions of the area most probably 

 exposed to fecal contamination during the most un- 

 favorable hydrographic and pollution conditions. 



(e) The reliability of nearby waste treatment 

 plants shall be considered in the approval of areas 

 for direct harvesting. 



(5) It is also essential to monitor continuously waste 

 from tar, gas, and coke, petroleum refinery, petrochemi- 

 cal, and pulp and paper mill operations. They all 

 produce complex wastes of great variability, not only 

 from facility to facility, but also from day to day. 

 This should be done on an individual basis with bio- 

 assays. These tests should be made at frequent inter- 

 vals to determine TLm values as described for other 

 wastes. For the more persistant toxicants, an applica- 

 tion factor of %oo should be used while for unstable or 

 biodegradable materials an application of %o is tenta- 

 tively suggested. 



(6) Concentration of other materials with noncumu- 

 lative toxic eff'ects should not exceed '-io of the 96-hour 

 TLm value. For toxicants with cumulative effects, the 

 concentrations should not exceed Yio and Hoo for the 

 above respective values. 



When two or more toxic materials that have additive 

 effects are present at the same time in the receiving 

 water, some reduction in the permissible concentrations 

 as derived from bioassays on individual substances is 

 necessary. The amount of reduction required is a func- 

 tion of both the number of toxic materials present and 

 their concentrations with respect to the derived per- 

 missible concentration. An appropriate means of assur- 

 ing that the combined amounts of the several substances 

 do not exceed a permissible combination for the mix- 

 ture is through the use of following relationship: 



Ct 



C. Cb 



-£-: 



Where C, Cb . . . C„ are the measured concentra- 

 tions of the several toxic materials in the water and 

 La, Lb . . . L„ are the respective permissible concen- 

 trations (limits) derived for the materials on an in- 

 dividual basis. Should the sum of the several fractions 

 exceed one, then a local restriction on the concentra- 

 tion of one or more of the substances is necessary. 



92 



