PRODUCTION & SURVIVAL
Predation & competition. White
hake is listed as a food for harbour and
grey seals. White hake have been
found in cod stomachs and also white
hake stomachs.
Parasites & disease. The
parasites reported from white hake are few and
similar to those noted for red hake.
Species noted include two species of
protozoans, three myxosporidians, one trematode,
one nematode ( the
sealworm Phocanema decipiens ), and
one copepod. Blood parasites were
detected in 11 of 83 specimens of white
hake from the Newfoundland -Labrador
area.
White hake are caught in Canadian waters as a
by-catch incidentally while
fishing for other species, although directed
fisheries have been conducted
in the southern Gulf of St. Lawrence. Directed
fisheries have also been
carried out by foreign vessels. An
estimated 4000t was given as the average
sustainable catch for the southern Gulf.
Landings of 1000 - 9000 tons were
taken in the Grand Bank region in the early 1970's.
Because of the difficulty of distinguishing red
and white hake on the Scotian
Shelf, no estimates of Scotian
Shelf landings have been given.
Although treated as a"trash" fish five
years ago, the white hake is recognized
as a valuable food fish, providing it is
promptly dressed and refrigerated. The
flesh is white, flaky, and of good flavor.
It is marketed mainly as fresh and
frozen fillets.
A commercial catch rate series was used in past
assessments of this resource,
when it was assumed that each purchase slip
represented one unit of fishing
effort (per day ). This approach has not
been used since 1989 because the model
accounted for only a small percentage ( less
than 25% ) of the variation in previous
year and because errors were encountered in
the coding of inshore otter trawlers.
As a long term solution to this problem, the
Groundfish Index Fisher Program
was established in 1990. Since its start,
50 to 58 fishers volunteered to participate
in this program each year, about one quarter of
which are considered to fish at
least part-time for hake.
The trends in the catch rates for these eight
fishers are highly variable and
difficult to characterize except for the following:
-the catch rate series for the two otter
trawlers showed a marked decrease
in 1993 and 1994.
-three of the four catch rate series for
gillnetters exhibited an increase in 1994,
with two of the increases being pronounced.
- the catch rate series for one of the
longliners was stable from 1992 - 94
while the other showed an increase in 1994 from 1993.