426 
BULLETIN OF BUREAU OF FISHERIES 
Muriatic acid 
See hydrochloric acid. 
Naphthenic acids and naphthene derivatives 
These compounds are listed among the solutes which may occur in refinery wastes (American 
Petroleum Institute, 1935), and Kupzis (1902) believes the naphthenic compounds to be among 
the most toxic substances to fish, passing from crude oil into water. Kupzis (1. c.), using 
fractions containing the naphthenic acids extracted from various crude oils, gives the following 
lethality findings for this naphthenic acid fraction (which of course must not be considered as 
representing a single pure compound in this case). In tap water (hard) 3 p. p. m. killed percoid 
fishes, Acerina cernua, in 6-12 hours; 5 p. p. m. killed pickerel, Esox lucius, 36-48 hours; the minnow, 
Abramis brama, 72 hours; the red-eyed minnow, Scardinius erythrophthalmiis, 26 hours; and the 
perch, Perea fluviatilis, in 16-23 hours; 20 p. p. m. killed carp, Cyprinus carpio, in 26-36 hours, and 
goldfish, Carassius auratus, in 8-16 hours. Several other European species tested are not listed here. 
Naphthalene, CioHg 
Aniline and coal-tar industries. Demyanenko (1931), 10 p. p. m. lethal to fish. 
Nickelous chloride, NiCh 
Electroplating wastes; various industrial wastes. Thomas (1924), 8.1 p. p. m. in tap water 
killed the top-minnow, Fundulus heteroclitus, in a few hours. This species, which can also live in 
salt water, tolerated 259.2 p. p. m. when in salt water without apparent injury during a 2-week 
exposure. M. M. E., 100 p. p. m. in very soft water killed goldfish, Carassius auratus, in 19-50 
hours, and 10 p. p. m. in very soft water killed in 200-210 hours. 
Nitric acid, HNOj 
Occurs in many wastes from chemical industries. It is easily broken into water and oxides of 
nitrogen. Weigelt, Saare, and Schwab (1885), trout after 34 minutes in 1,000 p. p. m. in tap water 
were helpless; Carpenter (1927), sufficient quantities to bring the water to pH 4.4 killed the minnow, 
Leuciscus phoxinus, in 7 hours, while quantity sufficient to bring the water to pH 5.2 was without 
apparent effect on this species of fish; M. M. E., 750 p. p. m. in hard water (see section on acids) 
killed goldfish, Carassius auratus, in 30 minutes to 1 hour, and 200 p. p. m. in hard water were 
without apparent effect on goldfish in exposures of over 100 hours. 
Octyl alcohols, general formula CsHnOH 
Macht and Leach (1930), 66.7 p. p. m. of primary oetynol produce respiratory and neuromus- 
cular paralysis in goldfish, Carassius auratus, in 15 minutes. The specific toxicity for fish of the 
individual octyl alcohols varied in the series of 23 which these observers studied, secondary octylie 
heptanol being among the least toxic, 200 p. p. m. producing paralysis in goldfish in 4 hours. 
Oxalic acid, H2C2O4 
Bleaching, dying, and various chemical industries. M. M. E., 1,000 p. p. m. in hard water 
killed goldfish, Carassius auratus, in 25-30 minutes; 200 p. p. m. in hard water produced no apparent 
injury during exposures of 100 hours. This acid is readily precipitated out of waters by calcium 
salts. 
Oxygen, O2, and Ozone, O3 
Although the usual problem in stream pollution is to secure enough oxygen, some of the proposed 
treatments for organic wastes involve high oxygenation or ozonation. It seems worth while there- 
fore to list here some tests on the effects of high oxygen and nascent oxygen. Wiebe (1933) found 
changes from 5.7 p. p. m. to 40.3 p. p. m. dissolved oxygen were tolerated by largemouth black 
bass, Micropterus salmoides, smallmouth black bass, Micropterus dolomieu, white crappie, Pomoxis 
sparoides, bluegill, Lepomis incisor, orange-spotted sunfish, Lepomis humilis, golden shiner, Notemi- 
gonus crysoleucas, and goldfish, Carassius auratus, for at least 24 hours. Hubbs (1930) states that 
minnows may be killed by 0.033 p. p. m. of nascent oxygen in the water and that fishes are irritated 
by ozone in quantities less than 0.01 p. p. m. 
Para-dichlorobenzene, C6H4CI2 
Demyanenko (1931), 50 p. p. m. lethal to fishes. 
