58 DEPARTMENT OF THE NAVAL SERVICE 
; 7 GEORGE V, A. 1917 
STEPS IN CONSERVATION. 
One of the earliest steps taken in most instances towards the conservation of 
natural oyster beds has been the enactment of a “cull law.” This compels the fisher- 
man to sort his catch on the bed, throwing back the unmarketable material, consisting 
of shells and small oysters. The main advantage secured is the conservation of a per- 
centage of the seed oysters. The spat attached to the large oysters cannot be removed, 
while the shells which are returned are largely silted up when spatting time comes. In 
fact, these shells, unless newly dug out of the mud, require to weather for weeks, 
exposed to rain, snow, sun, and air before they are suitable for spat collecting. 
It is evident that no fisherman would thus care for the shells, unless compelled by 
law; yet it seems to the writer that it would be a practically enforceable provision, were 
it embodied in the cull law, particularly if a market for these shells could be secured. 
Sometimes the State has purchased cultch and placed it on natural beds; but this prac- 
tice was abandoned for two reasons: the cost of the work was greater than under 
private enterprise; and the Government felt it was making a gift to a special class. 
Where oyster farming prevails, the planters would buy this cultch, particularly in 
those regions, where shells are scarce because no shucking operations are carried on. 
Now that oyster culture is under way in Canada, the securing of cultch is a matter of 
great concern. It appears that the most available supply must come from a sorting of 
the so-called “mussel-mud” dug out of dead oyster reefs. The firmest of these shells, 
which are often of large size, when washed clean, are good collectors. But no cultch 
should be planted until spatting has just begun. Happily, scientific oyster research 
has in recent years enabled us to closely determine this date; but important matters 
are still to be cleared up. 
THE RATE OF PRODUCTION OF A BED. 
The legal restrictions imposed on the fishermen have the object of conserving the 
natural oyster production. The cull law helps this in a measure. Another prominent 
legal provision is the “ close season” during summer, when no oysters are permitted to 
be taken, because it is believed that the spawning oysters should not be disturbed, nor 
the cultch be littered with silt by fishing operations. This “ close season” has been 
lengthened from time to time, at both ends, by shortening the “ open season,” in order 
to reduce the number of oysters taken, it being believed that the bed is unable to 
supply oysters in quantity equal to the demand. It is doubtful if this provision 
becomes effective unless made so drastic as to practically deprive the fisherman of his 
means of living. 
When these enactments fail, more drastic measures are advocated, such as the 
closing of the oyster beds for a number of yéars, until nature has had time to restore 
them. But such legislation is founded on a failure to grasp a fundamental principle,. 
to wit, a depleted oyster bed will be restored at a rate dependerit on the percentage 
of available cultch multiplied into the available spat. Assuming that there are still 
enough oysters remaining to produce a fair abundance of spat, and that there are 
plantings of cultch on the bed at the proper times, then it will take five years for the 
bed to reach its acme. Then if this bed were henceforth left undisturbed by man, 
the forces of destruction and of natural production would just balance. On the 
other hand, suppose there was no planting of cultch, then, under nature, a depleted 
bed would take an indefinitely longer time to reach its original condition. In any 
event, after such a bed has reached the point of highest production, a survey of its 
extent and examination of an average square yard or rod, will enable one to calculate 
just how many bushels of oysters are present. Knowing then the number of bushels 
that can be taken in the open season, it can easily be reckoned how many years will 
elapse before the bed again will be reduced to a point where the fishermen can not 
secure their average catch. It should be evident that under artificial culture the 
