NATURAL HISTORY OF THE BAY SCALLOP 
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time some of them are only about 14 months old, many not over 16 months, and the 
majority not over 18 months. Great numbers of scallops are caught in December 
when many are about 12 months old, and the majority not over 14 months. Under 
present conditions the length of life of the majority of scallops attaining to maturity 
may be taken to be from 12 to 18 months. 
The normal length of life may or may not be a very different thing from the 
general length of life of mature scallops. Bekling (1910) found that Massachusetts 
scallops (which spawn in June and July) suffered a heavy mortality in the spring 
following the market season and when lacking a few months of being 2 years old. 
Only a few survived to 2 years and a second spawning. This was the more remark- 
able because in all cases noted development of sexual products in preparation for a 
second spawning began and continued normally until death intervened. This sug- 
gests not death from old age but from some pathologic factor. A few survived to a 
second spawning and even to an age of 30 months. 
Because destruction of adult scallops by man generally is so extreme in North 
Carolina, the problem of the normal length of life, or the length of life of scallops not 
destroyed by man, is difficult to determine. It is evident that some survive to 2 
years of age, or somewhat more but not what portion would do so. It is not even 
clear that there is any general mortality following the market season and preceding a 
second spawning (to correspond with the spring mortality reported by Belding). 
With scallops of rapid growth, such as those at Fivers Island, growth becomes 
slower after the second winter and there is no reason to believe that the normal span 
of life is much over 2 years. Questions of practical importance are what proportion, 
if spared by man, would survive to a second spawning, and what proportion would 
survive to a second market season; that is, third winter. The evidence is scanty and 
inconclusive. 
As judged by the prevalence at all times of various sized shells of recently dead 
scallops, there is considerable mortality at all times and ages. Because of this, any 
special mortality rate, among the few scallops ordinarily spared at the end of the 
market season, must be rapid and heavy to be definitely determined. There are no 
direct observations nor data to show such mortality. It is possible, however, that 
there is a gradual but high mortality through the second summer and the following 
autumn. Unless freshets or other natural agencies caused special destruction this 
could be determined if man did not interfere. 
When the market season closed in the spring of 1929 there were still, as scallopers 
and dealers have stated, many adult scallops remaining in western Bogue Sound. 
This was because, on the one hand, these small scallops had been very abundant 
and, on the other, the market was poor. These small scallops bring the lowest 
return and in such a season are hardly desired by the dealers at any price. When I 
visited western Bogue Sound in November, 1929, I found among the usual small 
1-year-old scallops (40-54 millimeters but principally 45-50 millimeters long) com- 
mercial quantities of scallops of large size (many of them 75 to 80 millimeters, some 
as small as 70 and one 65 millimeters long). These large scallops have an evident 
annual growth line (see succeeding paragraphs) at about 50 millimeters. There 
seems no reason to doubt that they were 2-year-old scallops. 
Thus it is shown that in some situations scallops may survive to 2 years or more 
of age in considerable proportion and quantity. It is also shown that in so doing 
they may increase greatly in bulk and consequently in value. This leads to another 
question: Do the scallops of slow growth, and consequent small size at 1 year of age, 
