PRODUCTION AND COLLECTION OF SEED OYSTERS 
251 
EXPERIMENTS IN 1925 
In the United States, brush spat collectors have been employed but very little 
chiefly because of the cheaper and better results generally obtained with oyster 
shells. Brush, however, is superior to shells in many respects and in certain regions 
has proved to be a very suitable collector for use on soft mud tidal flats which can 
not be utilized for any other purpose. In Connecticut the profitable utilization of 
soft muddy tracts by brush methods is described in the reports of the Connecticut 
Shellfish Commission for 1882 and 1883. At that time 50 acres of muddy bottoms 
in the Poquonock River near Groton were planted with white birch brush and yielded 
as high as 1,000 bushels of oysters per acre. The brush or really young trees which 
were used, measured around 4 inches at the butt and are said to have yielded as 
much as 25 bushels on one branch. The average yield, however, is said to have been 
approximately 5 bushels per branch. 
For the experiments in Milford Harbor in 1925, white birch brush or branches 
were used having a length of approximately 6 feet and a diameter at the butt ranging 
from 1 to 2 inches. The branches were forced into the soft bottom areas at an angle 
of about 45° and were arranged in two different formations: (1) In rows at right angles 
to the direction of the tidal currents and (2) in conical stacks having a diameter at 
the base of about 8 feet. The branches were set out a few inches apart and were 
forced into the mud from 6 inches to a foot deep according to their size or length. 
The planting of the brush was carried on during the first two weeks of July, the 
operations being confined, of course, to the periods of low water. The areas selected 
for planting were flat and even and were located at a level corresponding almost 
exactly with that of mean low- water mark. 
Two weeks after the brush planting was completed the setting of the oyster larvae 
occurred and was the heaviest observed in this harbor in many years. Studies of 
the setting (from the standpoint of number per collector, etc.) were not made until 
the first week in September by which time the spat had attained an average diameter 
of one-half inch. The number, distribution, and size of the oyster spat on the branches 
was determined for samples taken from each planting formation and was compared 
with the results obtained in the baskets of shells and tile collectors which were planted 
on the same areas. 
The number of spat per branch was found to vary in regard to the location 
of planted area in relation to the spawning bed, the diameter of each branch or 
twig, and the formation in which each branch was planted. On branches having 
practically the same diameter at the butt the number of spat ranged from ap- 
proximately 25 to 300 spat per branch which is quite a low figure in view of the 
surface area offered for attachment of the oyster larvae. The branches which were 
set out below the spawning bed collected nearly twice as many spat as those which 
were put out upstream or above the bed. Where branches of different size were 
planted under the same conditions it was found that those having the greatest di- 
ameter collected the largest number of spat and that twigs in the same zone having 
a diameter less than one-fourth inch rarely had spat attached to them. The same 
general condition was observed in comparing the brush planted in stack formation 
with that planted in rows. In the stacks the branches were massed closer together 
and offered greater resistance to the tidal currents with the result that it was easier 
for greater numbers of larvae to become attached to branches under these conditions. 
