18 MOBTALITY OF FISHES, WEST COAST OF FLOEIDA. 



rine, as hydrochloric acid or as ammonium chloride, or in any 

 soluble combination whatever, would certainly be detected by the 

 chlorine determination (salinity) ; sulphur gases and carbon dioxide 

 would alter the alkalinity of the water, though much would depend 

 on the freshness of the water when the determinations were made. 

 An unfortunate delay impaired the value of the samples collected; 

 it was therefore impossible to determine whether or not these gases 

 were present. 



Similar remarks concerning natural gas issues may be made. Such 

 gases consist, of course, largely of the light paraffins, usually small 

 quantities of olefines and occasionally some carbon monoxide. Little 

 is known of the effects of these gases on fish. The injury to man 

 done by methane is done chiefly or entirely by the mere dilution of 

 the air by this gas. Ethylene and ethane probably act in a similar 

 manner. These gases are slightly soluble in water, ethylene to the 

 extent of 4 per cent volume. In water these gases could not act as 

 they do in air, for the solubility of a gas is quite independent of all 

 other gases and as much oxygen would be present in a saturated so- 

 lution of any of them as in their total absence. 



Of carbon monoxide more can be said. This gas acts as a poison 

 to animals, whose respiration is dependent on a blood pigment by 

 combining firmly with the pigment to the exclusion of oxygen; while 

 these animals situated in the presence of abundant oxygen and pre- 

 senting a wide area of " semipermeable " skin, and whose respiration 

 is performed by the agency of oxygen dissolved in the blood plasma, 

 are immune, since carbon monoxide does not interfere with the pas- 

 sage of oxygen into the body (Leitch, 1916). Carbon monoxide is 

 soluble to a sufficient extent thus td iht^rfere Avith respiration. It is 

 therefore suggestive to note that all the animals killed, except sponges, 

 were dependent on a blood pigment (hseiiioglobin, hsemocyanin, echi- 

 nochrom, etc.). Sponges are the only animals observed on the 

 beaches whose respiration is not dependeiU on one of these carriers 

 or pigments, but sponges are often seen, even in normal times on the 

 beaches. 



In February and March, 1891, the AWatross investigated and re- 

 ported on a case of widespread mortality of fishes off the coast of 

 California between Santa Barbara and San Diego. Evidences thej-e 

 obtained indicated petroleum and hydrocarbon gases as the cause of 

 the disaster. Many species were killed, but those dead Avere chiefly 

 flatfish and barracuda. The odor of petroleum was evident from the 

 (lead fish. The body slime was colored yellow in patches, and the gall 

 bladder was ruptured. The oil springs snid to exist oil the coast were 

 held responsible for the oil and gas issues. 



