174 
BULLETIN OF THE BUREAU OF FISHERIES 
ECOLOGICAL OBSERVATIONS 
SPAWNING 
No set of oysters has been obtained in Oakland Bay for three years, and at 
present, the live oysters are in an abnormal physical condition. During the summer 
of 1929 reproductive products were formed only in a very few individuals. Three 
specimens containing eggs in the segmentation stage were found, and although a 
great many oysters were examined during the course of the summer, none was found 
which contained shelled larvae (commonly called “black spawn”) in the mantle 
cavity. 
Failure of set has been experienced in other bays. Eld Inlet (Mud Bay), prior to 
1928, was considered to be poor setting ground. The set in Hood Canal and North 
Bay was also very light for several years. However, in each case outside of Oakland 
Bay, the oysters developed sexual products, and spawned normally. Either natural 
water conditions made the mortality of larvae high, or proper cultch was lacking. At 
any rate, in all cases a few seed were found each year. 
In May, 1929, over 200 bushels of adult oysters were moved from North Bay to 
Oakland Bay. They were in good condition and spawned; the larvae were carried 
the proper time, and liberated apparently in good condition. So far as is known, these 
were the only oyster larvae in Oakland Bay during the season, and not a single seed 
oyster has been found on shells on the beds. Special spat collectors developed by 
the Bureau of Fisheries were placed on various parts of the bed and caught 25 seed 
oysters on 2% bushels of shells, an average of 1 spat to 1,000 shells. 
The failure of the set was probably due to two or more related factors. The 
adult oysters failed to develop sexual products, which precluded any chance of 
spawning, and the conditions which affected the adult oysters probably prevented 
normal development of the larvse from introduced oysters. 
Water samples, taken in April from Oakland Bay and held in tightly stoppered 
bottles, were examined to determine their affect on oyster larvse. Dilutions of one-sixth 
and one- tenth were tested with normal sea water for control. Samples of water taken 
near the southern end of Oakland Bay caused an instantaneous reaction in which all 
larvse closed their shells and sank to the bottom. A sample taken over the oyster 
beds produced a less sharp reaction. A few larvse were swimming about after one 
day in the weaker solution, but later observations showed no movement. In normal 
sea water the larvse continued to live and swam about the dish continually. The 
water was changed at bi-weekly intervals, and no dead larvse were noted for nearly 
three weeks. 
It is probable, therefore, that water conditions in Oakland Bay were unfavorable 
to the larval oyster and resulted in the death of nearly every one. 
GROWTH OF BARNACLES 
Not only the oysters in Oakland Bay have been affected, but other organisms 
as well. Some forms have, apparently, been stimulated; others suppressed. To 
illustrate this point we might refer to the floating equipment used about the oyster 
beds. It is a universal practice to scrape and repaint floating equipment at regular 
intervals, for, under normal conditions those parts of objects which are immersed in 
sea water are quickly covered with plant or animal growth. Boats and scows used 
on the oyster beds have always been cleaned and repainted at least once a year, but 
in the last three years no growths have appeared, and the work of reconditioning has 
