The results of the sediment bioassays with the bioluminescent bacteria, 
fish cells and oligochaetes provide subtle end points (as opposed to 
lethality). They may, in part, be responsive to chemicals that are not 
acutely toxic. The anaphase aberration test, for example, is known to be 
responsive to mutagens and promutagens in laboratory tests. These tests 
have provided results that usually corroborate the results of the acute 
toxicity bioassays; samples from the same sites were toxic to both. 
However, as would be expected, there have been differences in the results 
also. 
Biological indicators. 
Measures known to be indicative of the exposure of organisms to 
contaminants have been made with crabs, clams, fish, marine birds, and 
marine mammals captured or observed in the Sound. Some are listed in 
Table 3. 
Histopathological disorders in fish and crabs . The most widely-used 
measure has been that of histopathological disorders in bottomfish, 
especially English sole. Over 300 adult flatfish such as English sole 
from the bays and harbors of Puget Sound have been studied extensively to 
determine if they show signs of disorders possibly linked to chemical 
contaminants. Attention has been specifically focused upon disorders of 
their livers. A wide variety of disorders have been discovered and 
identified. Some occur in fish essentially everywhere and probably have 
nothing to do with pollution. Others, however, seem to only occur in 
statistically significantly higher frequencies in those portions of the 
harbors and industrial waterways that are most contaminated. 
The highest prevalences of degenerative liver lesions found in areas 
studied thus far have been in Eagle Harbor, Everett Harbor, the lower 
Duwamish Waterway, some of the waterways in Commencement Bay, and along 
the Ruston shore in Commencement Bay. Areas with none or very few fish 
with these conditions include Budd Inlet, Case Inlet, Carr Inlet, outer 
Elliott and Commencement Bays and Discovery Bay. Only one fish among 
about 900 examined from the Central Basin near Des Moines and Pt. Pulley 
had a tumor-like lesion of the liver. More specific data from these 
analyses are presented in a paper by Bruce McCain in this volume. 
The areas with highest prevalences of lesions are usually those known to 
be most contaminated with toxic chemicals. However, this co-occurrence 
does not necessarily mean the liver lesions are caused by the chemicals. 
They could be caused by or exacerbated by viruses, dietary deficiencies 
and other stress factors either exclusively or in combination. 
Crabs and shrimp from some parts of the Sound have been captured and 
examined for signs of sublethal disorders. The gills, gut, antennal gland 
at the base of the antennae, and hepatopancreas (equivalent to our livers) 
have been studied. About 40% of the crabs caught in the waterways of 
Commencement Bay had necrosis, or damage, of the hepatopancreas, as 
compared to 15% to 20% in the Duwamish Waterway and less than 10% in 
36 
