EFFECTS OF PULP MILL POLLUTION ON OYSTERS 
By A. E. HOPKINS, Ph. D., Aquatic Biologist, PAUL S. GALTSOFF, Ph. D., In Charge, Oyster 
Fishery Investigations, and H. C. McMILLIN, Junior Aquatic Biologist 
CONTENTS 
Page 
I. The effect of sulphite waste liquor 
on the oyster ( Oslrea lurida) (by 
A. E. Hopkins) 125 
Introduction 125 
Sulphite waste liquor 126 
Material and methods 129 
General considerations 132 
Experiments with acid liquor 134 
Experiments with neutralized 
liquor 145 
Sensory reaction to liquor 147 
Discussion of results 148 
Summary and conclusions 160 
Bibliography 161 
II. The effect of sulphite waste liquor on 
the rate of feeding of Ostrea lurida 
and 0. gigas (by Paul S. Galtsoff) __ 162 
Page 
III. Investigations of oyster mortality in 
Oakland Bay, Wash, (by H. C. 
McMillin) 167 
Introduction 167 
Survey of the beds 168 
Ecological observations 174 
Spawning 174 
Growth of barnacles 174 
Plant growth 175 
Possible effects of log stor- 
age 175 
Possible effects of domestic 
sewage 176 
Sulphite waste liquor pollution. . 176 
Concentration of liquor in Oak- 
land Bay 180 
Conclusions 184 
References 186 
I. THE EFFECT OF SULPHITE WASTE LIQUOR ON THE OYSTER 
( OSTREA LURIDA ) 
By A. E. HOPKINS 
INTRODUCTION 
The purpose of the present investigation, which was undertaken at the request 
of the oystermen of Shelton, Wash., was to throw some light on the difficulties faced 
by the oyster industry in Oakland Bay, where oyster culture has suffered a setback 
amounting to almost complete cessation. Oysters are adapted to life in inshore 
waters which are considerably diluted by land drainage and where the conditions of 
their natural habitat may be subjected to changes caused by the addition of waste 
matter of wide variety. Suspicion had been directed toward the waste liquor poured 
into the bay from a pulp mill established on Oakland Bay in 1927, for in this industry 
there is necessarily a large amount of commercially worthless material remaining 
after the pulp is removed from the wood. Inasmuch as little experimental work 
has been done which can serve as a basis for predicting the effect on the oyster 
industry of waste matter discarded from the factories, it is important to determine 
just what possible effect certain specific waste substances may have upon the life 
of the oyster. It was expected that the present investigation would show what effect 
pulp-mill wastes may have on the oyster and would serve as a foundation for general 
1 Approved for publication Mar. 11, 1931. 
66424—31 
125 
