EFFECTS OF PULP MILL POLLUTION ON OYSTERS 
185 
(2) Other animals, clams, barnacles, mussels, and hydroids, and at least one 
marine plant, Melosira borreri, living on the oyster beds, have been affected in a 
peculiar manner. Boats, scows, and other floating equipment which have never left 
the vicinity of the oyster beds do not become covered with barnacles, mussels, and 
hydroids, which grow upon such equipment under normal conditions. These animals 
thrive under a wide range of physical conditions, and their absence can not be 
explained by abnormal temperature or salinity of the water. 
(3) There is no evidence by which sewage, log storage, or sawdust could be 
reasonably considered as an agent of destruction. 
(4) The diatom, Melosira borreri, normally found in small amounts on oyster 
beds throughout the lower end of Puget Sound, has changed the character of its 
growth in Oakland Bay. Apparently this plant is able to use to advantage the chem- 
icals now found in abnormal concentrations in the waters of Oakland Bay. Dense 
masses of it grow in places where the current is slow, but the area upon which it is 
found is not the place of highest mortality of the oysters. Some beds which contain 
the greatest percentage of living oysters have been continually covered with masses of 
Melosira. 
(5) Sulphite waste liquor reaches the oyster beds. Its characteristic color has 
been constantly present in the water over the oyster beds since the mill started opera- 
tions. 
(6) Since the chemical nature of lignin is unknown and since its oxidation prod- 
ucts are likewise obscure, no chemical means can be relied upon to demonstrate its 
presence or absence, in contradiction to visual evidence and observations on the 
currents. 
(7) The “oxygen balance” test is only a measure of stability of dissolved mate- 
rials, therefore the oxygen demand of any dilution of sulphite liquor is not a reliable 
index to its toxicity to oysters. 
(8) Due to the configuration of Oakland Bay and adjoining bodies of salt water, 
a small proportion of polluted water escaped each day, and continuous dumping of 
liquor at the mill gradually builds up a high concentration in the bay. 
(9) The dumping of 70,000 gallons of sulphite liquor daily would build up a 
concentration of 1 part liquor to 931 of water in Oakland Bay. Hopkins has shown 
(see accompanying report) that the important abnormal conditions of the oysters in 
Oakland Bay can be reproduced under controlled conditions in the laboratory by 
subjecting oysters to treatment by mixtures of liquor and sea water of the same 
strength as shown to be present in Oakland Bay. 
Increase in concentration of sulphite liquor in Oakland Bay caused by discharge of 70,000 gallons per 
day at the mill, calculated from formula 5 
Parts sea 
Number water per 
of days 1 part liquor 
1 102, 940 
10 12, 596 
50 2, 905 
100 1, 730 
150 1, 356 
Parts sea 
Number water per 
of days l part liquor 
200 1, 183 
250 1, 086 
300 1, 033 
350 1, 002 
co 931 
