University of Virginia Library

THE RATIO BETWEEN LARGE AND SMALL OYSTERS.

Any bed is on the road to destruction if the number
of old oysters which are removed from it each year is
as great as the number of young ones which are growing
up to take their places. Oysters, like other animals,
are exposed to many accidents, and the number
which can be taken from a bed annually is equal to
the number which are growing up to take their places,
less the number which will be destroyed by the accidents
of nature.

An accurate count of the oysters of various ages
upon a bed, therefore, gives us a means of deciding
whether it is or is not in danger of exhaustion.

We have examined in this way the oysters upon
the beds which we have visited, and have divided
them into four classes. The first class includes
large oysters, or all oysters of which a bushel does
not contain more than 250; the second class includes
medium oysters, or those between 250 and 400 to the
bushel; the third class includes the small oysters,
those which are large enough to be seen and counted
without difficulty, and more than 400 to the bushel;
and the fourth class, or "young," those which are less
than one-half inch long.

The accompanying table shows the number of oysters
of each class which we obtained upon the beds
which we visited, and the ratio between them.

Thus we found upon the Bodkin bar in November,
1882, no large oysters, 225 medium oysters, 355 small
ones, and no young, and there were at that time 100
small ones for each 67 of medium size.

In June, 1883, we found no large ones, and the
small ones which we had found in November had
grown to a medium size, and there were no small ones
growing up to take the places of these when removed by
the season's dredging. This result seems at first sight
to indicate that the fishing this season (1884) will exhaust
the Bodkin bed and put an end to work there,
but in truth the case is not quite so discouraging, for
our second examination was made before the end of
the spawning season, and an examination in the fall
might have given a different result.

In order to be trustworthy, an examination of this
kind should be made every year, in the same month,
and if the oysters of various sizes upon each bed could
be counted twice every year, in May or June, and in
September or October, the results would be very
valuable and would soon furnish a very exact means
for ascertaining the condition of the beds. This evidence
would be the more valuable, as it would soon
enable us to determine, a year or more in advance,
how many marketable oysters a bed could yield without
injury.

In the absence of any records of the numbers of
oysters of various sizes in previous years, our table is
of no particular value, but we give it in full, in order
to facilitate the work of comparison in the future.

Table No. 3.—To Show the Number and Ratios of Oysters
of Various Sizes.

                                                                                                                                           

	Large, or less than 250 to the bushel.	Medium, or from 250 to 400 to the bushel.	Small, or more than 400 to the bushel, but large enough to count.	Young too small to count.	Ratio of large to medium.	Ratio of medium to small.
Bodkin, November, 1882	0	225	355	0		.67
Bodkin, June, 1883	0	314	0	0
Sandy Point, June, 1883	133	176	0	0	.75
Sandy Point, November, 1882	0	155	700	many.		.207
Hackett's Point, November, 1882	600	2,025	0	0	.29
Hackett's Point, June, 1883	108	425	0	0	.25
Swan Point, November, 1882	300	2,250	0	few.	.133
Swan Point, June, 1883	34	49	0	0	.69
Chester River, June, 1883	110	79	0	0	2.14
Cornfield Creek, June, 1883	0	463	0	few.
Thomas' Point, June, 1883	102	0	0	0
Tally's Point, June, 1883	197	271	103	0	.2	2.
Eastern Bay, June, 1883	13	146	53	0	.0	2.
Eastern Bay, November, 1882	50	525	0	few.	.009
Tilghman's Point, June, 1883	0	101	85	0		1.2
Scull Hall, June, 1883	91	140	0	0	.65
Chink Point, June, 1883	0	777	0	0
Cook's Point, June, 1883	0	123	0	0
Benoni's Point, June, 1883	0	0	430	few.
Chlora's Point, June, 1883	0	0	40	0
Todd's Point, June, 1883	0	8	0	0
Castlehaven, June, 1883	0	6	0	0
Horn Point, June, 1883	0	0	150	few.
Choptank, June, 1883	0	137	620	0		.22
South River, June, 1883	0	0	225	many.
Shackel's Point, June, 1883	0	190	0	0
Duvall's Bar, June, 1883	0	0	200	few.
Brewer's Point, June, 1883	0	340	0	0
Purdy's Point, June, 1883	0	165	0	0
Round Point Reef, June, 1883	495	0	0	0
Saunders' Point, June, 1883	0	802	0	0
Poplar Island, November, 1882	218	15	210	few.	1.24	.3
Poplar Island, June, 1883	0	124	0	0
Three Sisters, November, 1882	450	208	0	few.	1.91
Three Sisters, June, 1883	23	13	0	0	1.19
Sharp's Island Rock, November, 1882	400	00	0	many.	.44
Sharp's Island Rock, July, 1883	21	143	0	0	.146
Little Choptank, July, 1883	0	0	28	0
Ragged Point, July, 1883	0	78	0	0
Hill's Point, July, 1883	80	0	0	0
Nigger Head, July, 183	0	37	0	0
Near Holland Point, July, 183	0	182	0	0
Holland Point, July, 1883	0	0	193	0
Plum Point, July, 1883	23	0	0	0
Daddy Dare, July, 1883	0	121	0	0
Steps, July, 1883	0	22	0	0
Little Low Point, July, 1883	0	308	0	0
Patuxent River, July, 1883	0	0	158	many.
Hawk's Nest, July, 1883	0	0	569	many.
Broom's Island, July, 1883	0	0	872	0
Patuxent Middle Ground, July, 1883	0	339	0	0
Thomas' Bar, July, 1883	0	0	205	0
Kent Island, November, 1882	180	160	0	0	1.12
Kent Island, July, 183	22	59	10	0	.37	5.9
Bloody Point, July, 183	45	49	0	0	.91
Potomac No. 1, January, 1883	0	151	0	many.
Cornfield Point, August, 1883	0	0	513	many.
St. Mary's River, August, 1883	0	0	226	many.
St. George's Island, August, 1883	0	705	0	many.
Piney Point, August, 1883	0	0	66	many.
Great Rock, November, 1882	7	407	401	0	1.83	1.01
Piney Island Bar, November, 1882	0	700	325	0		2.15
Fishing Bay, November, 1882	0	227	212	0		1.07
Fishing Bay, November, 1882	0	46	8	0		1.21
Hooper's Strait, November, 1882	0	0	4,000	many.
James' Point, November, 1882	0	0	111	many.		.3
No Point Bar, November, 1882	84	213	130	0	9	1.60
Turtle Egg Rock, November, 1883	191	164	0	few.	1.16
Total	4,717	15,6	11,8

The precise significance of this table cannot be understood
until similar examinations have been carried on
for a term of years, and at the same time in each year.

It will be observed, however, that it shows a total of
20,390 large and medium oysters to only 11,848 small
ones. Four thousand of these small oysters were
taken at one time in Hooper's Strait, in a "pocket"
which had escaped the dredgers, and this haul should
be omitted in order to show a typical average. If we
leave it out we shall have 20,390 large and medium
oysters to 7848 small ones, or only a little more than
one small one to three marketable ones. It is very
probable that if all our examinations had been made
in the fall, the number of small oysters would have
been found much greater, and they are above the
average on the beds which we examined in November.

Still the summary of the whole table shows that the
beds are losing their fecundity, and that the crop this
winter (1883-1884) will be greater than it will be the
year after.

The reasons for the small number of young oysters
we believe to be, in part, the scarcity of mature oysters
to furnish spawn; in part the wanton destruction of
great numbers of very young oysters through the violation
of culling laws, and in part the absence of enough
clean shells on the beds to furnish attachment for the
spat.

There are unlimited numbers of old, decayed and
dirty shells on all the beds, but on many of them we
found hardly a single shell proper for the attachment
of spat.

We regard the annual examination of the beds, in

the way we have employed, as a matter of very great
importance. In the absence of such observations it is
impossible to state with perfect certainty how many
oysters a bed may yield annually without injury. This
examination should be made every year, during the
same months, and it should be made under the superintendence
of the same person, in the same way, in order
that the results may admit of direct comparison. Provision
should be made for the annual examination of
all the beds under the direct control of the State.
The proper time for this examination is the closed
season. An examination after the year's dredging
would show how many full-grown oysters remain and
how many the bed might safely yield during the next
season. If the examination were made late in the
summer it would also show how many young oysters
have become attached during the spawning season.

While our own work was not exhaustive enough
to give the information which is necessary for this purpose,
it was amply sufficient to show that in 1882 and
1883 the deterioration of our beds had made rapid
progress, and that our system of managing the beds
was a failure.

The next step in our inquiry was to find the defects
in our system, and to point out the reason for its failure,
and this task was found to be an easy one, for
the experience of other countries which have passed
through the same history gave a clear and simple explanation.