PROGRESS IN BIOLOGICAL INQUIRIES, 1926 553 
6. Crates closely packed together collected a heavier set than those 
ret out alone. 
Wareham River—During the summer of 1926, observations and 
experiments with mea collectors were conducted in Wareham River, 
Mass., by Dr. P. S. Galtsoff and R. W. Crosley. In this region, the 
oystermen scatter oyster or scallop shells over the bars exposed a 
low water, and seed ‘oysters usually are gathered and sold in Beiober 
or November. The salinity of the water in this region varies from 
14 to 29 parts per thousand; the mean tidal range is about 4 feet; 
the tidal currents, measured in September, 1921, are not very strong 
on the flats, seldom exceeding one-third foot per second. 
On July 19, 50 crates were planted in various sections of the river. 
During the six weeks that the crates were in the water, eight of them 
were broken and carried out by the tide. All the losses ‘occurred in 
the crates planted on the west side of the river, those on the east 
side sustaining the test successfully. In September the crates were 
examined and the seed oysters on the shells were counted. 
The results of the count show (1) that setting occurs above low- 
water mark and was found to be heaviest about 114 feet above the 
bar on which shells are planted by the local oystermen; (2) that the 
number of spat caught, per bushel of shell, varied from 1,900 to 
45,000, according to the location of the crate. 
Wellfleet Harbor—Similar experiments with spat collectors were 
carried out in Wellfleet Harbor during the summer by Dr. Henry 
Federighi, temporary investigator of the bureau. It has been found 
that the type of crate used in the experiment was not suitable for 
regions where strong tidal currents occur. Of the 97 crates set out 
in various sections of the harbor, only 43 remained, the rest being 
washed away. Though there was no setting of commercial me 
tance in the harbor, ‘the crates placed in Herring River caught ¢ 
fairly good set, varying from 1,200 to 2,900 spat per bushel. 
The ‘investigation in Wellfleet Harbor shows that the areas best 
suited for spat t collection are Herring River, Duck Creek, Egg Island, 
and Blackfish Creek. The best setting takes place at a point mid- 
way between high and low water marks. 
Briefly summarized, the results of the experiments and scientific 
studies show: 
1. The conditions necessary for successful spawning and setting 
are to be found primarily in the harbors, bays, and river mouths. 
2. Such inshore areas, if not grossly polluted, can be rehabilitated 
as prolific oyster-producing regions by the establishment of spawning 
beds. 
3. As shown by laboratory experiments on spawning under ad- 
verse seasonal conditions, the oysters on these beds can be induced 
to spawn. This was successfully accomplished in Milford Harbor. 
4. The oyster larvee will remain and set in the vicinity of the 
spawning beds in spite of strong tidal currents and river discharge. 
5. Triangular crates filled with shells can be placed on the tidal 
flats in the harbor and will collect from 2,000 to 50,000 oyster spat 
per bushel. 
6. By means of the crates, from eight to ten times as many seed 
oysters can be colJected on a given area as by ordinary methods of 
shell planting. 
