Fishery bulletin of the Fish and Wildlife Service - NOAA

160 FISHEBY BULLETIN OF THE FISH AND WILDLIFE SERVICE
COAST OF NOVA SCOTIA
Numbers and distribution.—Information on the occurrence of mackerel eggs
along the coast of Nova Scotia is limited to the results of a survey in 1922 reported by
Sparks (1929, pp. 443-452). 4 Stations were occupied along the entire coast from Cape
Sable to the Straits of Canso during the period May 31 to September 18, but no eggs
were taken after the middle of July. For the most part the hauls yielded very few
eggs, the average number taken being 14 per station, which presumably represents
the sum of three tows. 6 Although Sparks stated neither the dimensions of his nets
nor the duration of his tows, it may be presumed that at least the surface net was a
meter in diameter at the mouth and that the tows were 15 to 30 minutes in duration.
If so, the egg concentration was exceedingly low compared with the other regions.
Furthermore, the occurrence of eggs even in this low concentration was limited to a
relatively narrow band along the coast (table 1). Thus the waters along the Nova
Scotian coast are poorer in mackerel eggs than any others within the known habitat
of the species.
Season.—Spawning occurs along the Nova Scotian coast from about the last of
May to the middle of June.
TABLE 1.—Number of mackerel eggs taken per station in Nova Scotian waters at various distances from
shore
380
384
383
386
Station
Distance
Mites 1206И
Number of
eggs
2
в
19
11
381
386
382
'GuLF OF ST. LAWRENCE
Station
Distance
Milts 79
11
Number of
eggs
Numbers and distribution.—The Canadian Fisheries Expedition of 1914-15 explored
the Gulf of St. Lawrence during the spring and summer of 1915 (Dannevig,
1919, pp. 8-12). Their surveys were made with a meter net hauled at the surface for
10 to 15 minutes, supplemented in many instances by vertical hauls, which, however,
took few mackerel eggs. The average catch in horizontal tows was 324 eggs per
positive haul, and the largest catch was 3,800 eggs. Since eggs were taken at almost
all stations south of the 100-fathom contour marking the southern border of the
Laurentian Channel, it may be presumed that mackerel spawn over this entire area.
The numerous larvae taken there indicate that this area not only is the site of considerable
spawning, but also that conditions there are suitable for the development of the
larva. The largest larva taken measured 9 millimeters in length.
In addition to the catches in the southern part of the Gulf of St. Lawrence, a few
larvae were taken near Cape Anguille on the southwestern coast of Newfoundland.
Also, there was a number of mackerel eggs in a sample of fish eggs collected from the
Bay of Islands by the Newfoundland Fishery Eesearch Commission and referred
to the Bureau of Fisheries for identification. It thus appears that spawning takes
' In addition to Sparks's results there is the listing by Dannevig (1919, p. 60) of two mackerel eggs taken ott Halifax and one egg
(listed with a question mark) near Sable Island.
> According to Sparks, three tows were taken at each station: No. 6 net, about 7 meters deep; No. n net, 0-2 meters deep; No. 0
net, 23-27 meters deep.
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