Effects of Pollution on the Amino Acid Content 
of Mytilus edulis 
Rita D. Schafer 1 
ABSTRACT: In an attempt to determine the influence of polluted water on the 
amino acid content of Mytilus edulis , muscle tissue of specimens from a clean area 
was compared with that of specimens from polluted areas and with that of sped- 
mens transferred from clean to polluted water. Analyses were made by means of 
two-dimensional paper chromatography. The amino acids present under one type 
of environmental condition but not under another were cystine, cysteine, methionine, 
taurine/asparagine, and proline. 
It has long been known that marine waters 
containing pollutants affect in various ways the 
fauna inhabiting 'such waters. A number of 
studies have shown that pollution factors aid the 
settlement and growth of some species while 
inhibiting others. Wilhelmi (1916) points out 
that some species are so favored by such an area 
that they occur in numbers sufficient to permit 
them to be considered as pollutant indicators. 
Reish (1955, 1956, 1957^ 1957 b) calls atten- 
tion to the presence of Capitella capitata in all 
areas of pollution in southern California; and in 
a later study ( I960) , in which he classifies areas 
as to degree of pollution, he points out that 
each type of area is characterized by the presence 
of dominant species of polychaetes. Hartman 
(1950) states that near a disposal outfall in 
Santa Monica Bay, California, only two major 
groups of animals are present, the annelids and 
the crustaceans. Filice (1959) in discussing the 
distribution of bottom fauna in polluted estua- 
rine waters, states that the occurrence of some 
species as well as their concentrations will vary 
with the nature and degree of pollution. Blevgad 
(1932), investigating effects of pollution on 
bottom fauna, found "dead” areas at the point 
of sewage outfalls. He points out, however, that 
at a distance slightly over 100 m away, con- 
ditions are the same as at a greater distance. 
1 Allan Hancock Foundation, University of Southern 
California, and Immaculate Heart College, Los Angeles, 
California. Manuscript received December 22, 1961. 
McNulty (1957), in a study of the effects of 
pollution in Biscayne Bay adjacent to the Miami 
shoreline, indicates that pollution in some in- 
stances has had a beneficial effect on productivity 
of macropfganisms. Hartman (I960), summa- 
rizing the results of extensive selected sampling 
of 11 southern California coastal areas, states 
that productivity and variation of organisms 
differ according to types of sediments, depth of 
bottom, availability of food, and effects of waste 
discharges. She also noted that biomass values are 
lowest in shallow depths of Santa Monica Bay, 
an area into which the largest of the Los Angeles 
disposal plants empties. The biomass values of 
this region were comparable to those from oily 
samples taken in a more northern area. In addi- 
tion to these variations in ability to survive and, 
in some cases, to thrive in waters containing 
pollutants, it has been noted that the biochem- 
ical composition of some forms living in such 
an environment differs from that of the same 
species from clean waters (Schafer, 1961). 
Forms previously used for investigation were 
the abalone, Hdiotis cracherodii , and the crab, 
Pachygrapsm cmssipes. In these the free amino 
adds present In specimens from polluted areas 
were compared with those from nonpolluted 
areas. 
It is the purpose of the present study not 
only to evaluate the differences in amino adds 
in another organism from clean and polluted 
areas, but to investigate as well the effect upon 
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