Effects of Pollution on the Free Amino Acid Content 
of Two Marine Invertebrates 
Rita D. Schafer 1 
Recent reports have been received from some 
inhabitants of the southern California coastal 
area of a change in the texture and taste of cer- 
tain edible marine invertebrates. Investigation 
showed that the specimens so designated had 
been taken from areas known to be polluted. 
The term "polluted” as used here has been given 
the same meaning as that used in the ecological 
study by Reish (1956) on the San Gabriel River 
area: this meaning is the dictionary definition, 
"the act of making or rendering unclean.” 
It has been shown for some invertebrates 
that a change in environmental factors will 
produce a change in either histological or mor- 
phological composition. Kinne (1958) showed 
that a change in ectodermal cell shape can be 
induced in Cordylophora craspia by varying the 
environment from marine to brackish. Wilson 
and Armstrong (1958), after experimentation, 
concluded that Echinus eggs and larvae are af- 
fected structurally by the properties of sea water. 
It has also been demonstrated (Lane and Scha- 
fer, in progress) that a difference in diet may 
change the amino acid composition of muscle 
tissue in some invertebrates. Since this is known 
to be true under controlled conditions, the pos- 
sibility exists that a variation in tissue com- 
position might occur as a result of a polluted 
and consequently altered environment. 
This study was thus undertaken to determine 
(1) if the change in appearance and taste was 
accompanied by a change in amino acid com- 
position, and (2) the nature of the change, if 
one had occurred. 
Acknowledgments . The author is indebted to 
Dr. Norman Mattox of the Department of Bi- 
ology, University of Southern California, for his 
direction and valuable suggestions throughout 
the course of this investigation, and to the 
1 Allan Hancock Foundation, University of South- 
ern California, Los Angeles. Manuscript received July 
8 , 1959 . 
administration of the Allan Hancock Founda- 
tion for the use of laboratory facilities. She also 
wishes to express her thanks to Mr. Fred Zie- 
senhenne of the Allan Hancock Foundation 
and to Mr. John Fitch of the California Depart- 
ment of Fish and Game, for the collections of 
specimens from the islands; and to Dr. Donald 
Reish for the use of his data of measured oxygen 
from the Los Angeles Harbor area. This study 
was supported by a research grant from the 
United States Public Health Service of the Na- 
tional Institute of Health, no. RG-4911. 
MATERIALS AND METHODS 
The animals used for investigation were the 
abalone, Haliotis cracherodii Leach, and the crab, 
Pachygrapsus crassipes Randall. The abalone was 
selected for study, as it is the form in which 
the greatest difference in tissue texture and 
taste has been observed. P. crassipes was selected 
because of its wide distribution and marked 
tolerance of polluted conditions. These two 
forms also offer two extremes as to length of 
time in which the animals are directly subjected 
to the polluted water. Haliotis is exposed to the 
air only during periods of lower low tides and 
therefore is almost continuously within the in- 
fluence of the conditions prevailing in the pol- 
luted water. Pachygrapsus, on the contrary, lives 
in the high tide zone along a rocky shore or on 
floats rather than in the water in a wharf region 
and consequently is submerged only during pe- 
riods of high tide, and is directly subjected to 
the pollutants for comparatively less time than 
is the abalone. Collections were made from pol- 
luted waters and, for a basis of comparison, from 
waters known to be free of pollution. 
Specimens of Haliotis were collected along 
the shore at White’s Point in the Palos Verde 
region of the southern California coast, from 
San Clemente Island, Anacapa Island, and Santa 
49 
