stream. Brook trout also appeared among the dead fis h, and along the roads and in the woods
birds were dyi ng. All the life of the s tream was s tilled. Before the s praying there had bee n a rich
assortment of the water life that forms the food of s almon and trout—caddis fly larvae, living in
loosely fitting protective cases of leaves, stems or gravel cemented together with saliva, stone
fly nymphs clinging to rocks in the swirling currents, and the wormlike larvae of blackflies
edging the s tones under riffles or where the strea m spills over s teeply s lanting rocks. But now
the s tream ins ects were dead, killed by the DDT, and there was nothing for a young s almon to
eat. Amid s uch a picture of death and des truction, the y oung s almon the ms elves could hardly
have been expected to escape, and they did not. By Augus t not one of the young s almon that
had eme rged from the gravel be ds that s pring re mained. A whole year’s s pawning had come to
nothing. The older y oung, thos e hatched a year or more earlier, fared only s lightly better. For
every six young of the 1953 hatch that had foraged in the s tream as the planes approached,
only one remained. Young salmon of the 1952 hatch, almost ready to go to sea, lost a third of
their numbers. All thes e facts are known becaus e the Fis heries Res earch Board of Canada had
been conducting a s almon s tudy on the Northwest Miramichi since 1950. Each year it had made
a cens us of the fis h living in this s tream. The records of the biologis ts covered the numbe r of
adult s almon as cending to s pawn, the number of y oung of each age group pres ent in the
s tream, and the normal population not only of s almon but of other s pecies of fis h inhabiting the
s tream. With this complete record of pres praying conditions , it was poss ible to meas ure the
damage done by the s praying with an accuracy that has s eldom been matche d els ewhere.
The s urvey s howed more than the los s of young fis h; it revealed a s erious change in the s treams
themselves. Repeated s prayings have now completely altered the s tream environment, and the
aquatic insects that are the food of s almon and trout have been killed. A great deal of time is
requi red, even after a s ingle s praying, for mos t of thes e ins ects to build up s ufficient numbe rs
to support a normal salmon population—ti me meas ured in years rathe r than months. The
smaller species, such as midges and blackflies, become reestablished rather quickly. These are
s uitable food for the s malles t s almon, the fry only a few months old. But there is no s uch rapid
recovery of the larger aquatic insects, on which s almon in their second and third years depe nd.
These are the larval stages of caddis flies, stoneflies, and mayflies. Even in the s econd year after
DDT enters a s tream, a foraging s almon pa rr would have trouble finding any thing more than an
occasional small stonefly. There would be no large stoneflies, no mayflies, no caddis flies. In an
effort to s upply this natural food, the Canadians have attempted to transplant caddis fly larvae
and other ins ects to the barren reaches of the Miramichi. But of cours e s uch trans plants would
be wiped out by any repeated s praying. The budworm populations , ins tead of dwindling as
expected, have proved ref ractory, and from 1955 to 1957 s praying was repeated in various
parts of New Bruns wick and Quebec, s ome places being s prayed as many as three times. By
1957, nearly 15 million acres had been s prayed. Although s praying was then tentatively
s us pended, a s udden res urgence of budworms led to its res umption in 1960 and 1961. Indeed
there is no evidence anywhere that chemical s praying for budworm control is more than a
stopgap measure (aimed at saving the trees from death through defoliation over several
s ucces sive years ), and s o its unfortunate s ide effects will continue to be felt as s praying is
continue d. In an effort to mini mize the des truc tion of fish, the Canadian forestry officials have
reduce d the concentration of DDT from the ½ pound previous ly us ed to ¼ pound to the acre, on
backadmin
(backadmin)
#1