Evening public ledger. [volume] (Philadelphia [Pa.]) 1914-1942, 1921-03-12
BY W. +. MEEHAN
Superintendent Of tho Fsirmount Park
Auuarium

VI rum
AQUARIUM.
LIVERY year about this time there is
IL deep interest shown by nearly every
person in this city over the annual mi
grafton of shad in the Delaware river.
The Delaware shad is generally re-
garded as superior in flavor to all
others of the species with the possible
exception of those which enter the Con
necticut river, and not excepting the
admittedly high grade fish of the Sus-
quehanna.
Since Colonial days there have been
two periods of enormous supply and
two Of great scarcity. One Of the latter
which is now being experienced, began
just twenty years ago. The first period
of scarcity was due apparently almost
altogether to careless and destructive
methods of fishing, and its lowest ebb
was reached about 1880, when the ma
tional government and n little later the
state of Pennsylvania began the work
| of what is called artificial propagation.
The results were little short of mar
velous. Within ten years the catches
annually exceeded anything known in
the first period of plenty. The indus.
try of catching great food fish reached
! its zenith about 1903, but held fairly
we'll for two or three years longer,
until 1000, in fact, when there was
sharp and decided decline, decline
that has been continuous.
Don't Like Cold Water
The principal cause for the sudden
decline in the beginning Of the ne"
century and for few years thereafter,
was easily traccable. 1t is n fac,
known to fish culturists that shad vii
| riuar from fhnir =
known home in the ocean until the
water temperature has reached ap-
proximately sixty degrees, and only a
few scattering fish will venture with
fresh water under fifty degrees. Tht
water must be at least sixty before the
fish will ripcn their eggs and go through
the function of spawning.
In the year 1900. just as the fsl
were about assembling at the mouth
of Delaware bay there came great snow,
! falls in the mountains of northeast
Pennsylvania and in the Delaware
watershed of New York sending the
water temperature down below forty de-,
grees, and the water remained cold
until early June. :,
The catch was cut nearly in hall
| that year. For several seasons fol-
lowing weather and water conditions
| in the spring were nearly the same
Few ripe shad were found by the
fish culturistS and consequently the
number of shad fry planted yearly
was pitifully small proportionately
compared with the number of hsf
caught.
/ one season there were only 120 rine
/ females taken. or 1000. 900 eggs. Oi
these about 3.O00,000 were hatched and
the fry planted.
According to careful estimates, only
about 80 900 Of these fry were likely tc
live until they reached the sea in the
autumn. Between that time and ma
turity n tremendous proportion, prob
ably more than 80 per cent, were de
voured or otherwise met with fata
mishap.
Consequently there would be lcs'
than II. 900 mature shad OF the origlna
artificial Matching to enter the river
The total catch the year the eggs wer
taken was more than GO,OOO.
OF course, there was natural propagn
ton that year, but it is safe to assum
that the number did not exceed tina
performed by human agencies at III
Torrcsdale hatchery.
The figures given are fairly repre-
sentative OF every Sthl sihNN 49,
Under these circumstances there can b
no alternative but extinction OF tn
shad unless conditions change.
Spawning Grounds Damaged
But there are other conditions whic
make for the same deplorable end. Th
spawning grounds in the Delawar
below the city have been badly inj jure
by the necessary deepening Of the chan
, mel and the shOaling of the water nea
shore. This is one of the causes OF tn
hurt to the once great fisheries at Wash
ington Park, Gloucester and below.
I Increased water pollution is also bi
factor Increased navigation is prob
: ably another. The shad is an exceed
ingly timd fish. 1t even fears shadows
and the turmoil caused by the vast rive
craft is enough in itself to keep tn
shad out of the river.
When shad leave the sea and enter
river they do so for the sole purpos