DFO Research Literature

Selected Review of DFO Literature

The following gives a brief description of some of the scientific literature which was encountered when researching St. Georges Bay. The descriptions contain the papers' abstracts as well as other notable information.

Kenchington, T.J. (1980) The Fishes of St. Georges Bay, Nova Scotia. Canadian Technical Report of Fisheries and Aquatic Sciences 955: 154p.

Abstract: A survey of the fishes in St. Georges Bay, based primarily on bottom trawling, found evidence for the presence of 47 species and allowed estimates of the biomasses of 22 of these. For each species, distribution and abundance are discussed and related both to reports from elsewhere and to the local oceanography, which is reviewed. The majority of the species appear to be resident within the Bay all year, although their location and availability to fishing varies seasonally. The commercial fisheries are described. Since species are not valid ecological units for fish, the data were examined for intraspecific variability in distribution. This was found in four species. In explicable differences in length frequency between trawl sets occurred in five species which may indicate a tendency for similarly sized fish to occur together. The biomass density of fish in St. Georges Bay (over 9 tons/km²) is moderate, when compared to other areas of the northwest Atlantic.

Note: This paper also gives general descriptions of the Bay's oceanography (biological and physical), bathymetry, geology, geomorphology, climate, and sea ice. These descriptions are brief yet informative. St. Georges Bay is approximately rectangular with a surface area of 1180 kilometers squared. This Bay's shallow zone (<15m) is quite narrow but the bottom slopes to maximum depths of about 40m at the mouth. There appears to be four types of sediment in the Bay: Buctouche Sand and Gravel, Pugwash mud (50-90% silt and clay), Pugwash mud (95% silt and clay), and Map-Unit A (complex sediment with Pugwash mud over Buctouche Sand and Gravel or Pomquet Drift). Salinity varies between 27 and 31 parts per thousand and the mean surface circulation is a clockwise gyre (0.1m/s). The Bay is 70-90% frozen over by late January to early February. Ice breakup usually begins in April and May.

Lambert, T. C., D. M. Ware, et al. (1982). Spawning and early life history of herring and capelin in St. Georges Bay, Nova Scotia. Canadian Technical Report of Fisheries and Aquatic Sciences 1128: 56p.

Abstract: Herring enter St. Georges Bay in spawning waves roughly 21 days apart. Consecutive cohorts of larvae result; in 1973, eight of these could be detected in the plankton between May and December. During spring and autumn, larvae are hatched in St. Georges Bay, whereas summer contingents are immigrant and originate in the Pictou region.

There was an unusual occurrence of capelin in St. Georges Bay from 1975-1978. Spawning was similar to herring in that several cohorts were released at regular intervals. Capelin cohorts were more closely spaced (about 10 days) than herring cohorts; spacing appeared to be a function of both larval mouth size and growth rate.

Herring larval abundance and size was well correlated with zooplankton abundance and size. Reduction of interspecific competition between the larvae of herring and capelin appears to be achieved by limiting the occurrence of larvae of the same size at the same depth.

Note: Herring are most abundant during May and September in St. Georges Bay. These are referred to as 'spring' and 'fall' stocks. Both stocks have declined greatly and only areas adjacent to Ballantynes Cove, Havre Boucher and Port Hood are yielding any quantity. According to some fishermen, historic spawning sites use to be around Malignant Cove and Havre Boucher but they can now be found in small amounts at Ballantynes Cove and Port Hood. (All information refers to 1973-1982 data)

Drinkwater, K. F., G. W. Taylor, et al. (1983). Temperature, salinity, and sigma-t distributions in southeastern Magdalen Shallows, eastern Northumberland Strait and St. Georges Bay during July 1981. Canadian Technical Report of Fisheries and Aquatic Sciences 1144: 26p.

Abstract: Temperature, salinity and sigma-t data collected from the southeastern Magdalen Shallows, Northumberland Strait and St. Georges Bay during July, 1981, are presented. The surface layer in St. Georges Bay is deeper and contains warmer, higher salinity waters than that on the Magdalen Shallows. The characteristics of the Bay's surface waters more closely resemble the surface waters found near shore (within ~ 10km) along the coastlines of Cape Breton Island and mainland Nova Scotia. This similarity is consistent with the northeastward residual surface circulation along the Nova Scotia coast inferred from surface drifter data by Lauzier (1965) and Drinkwater and Taylor (1979).

Note: The main objective of the cruise was to determine how representative the biological and hydrographic properties within St. Georges Bay were of the southern Gulf of St. Lawrence. Studies conducted included vertical structure of particulates, phytoplankton and zooplankton, as well as temperature and salinity profiles.

Maynard, D. R., A. W. Landsburg, et al. (1988). Movement of lobsters (Homarus americanus ) in St. Georges Bay effect on the standing stock. Canadian Atlantic Fisheries Scientific Advisory Committee Research Document 88/33: 7p.

Abstract: Nineteen hundred and sixty eight lobsters (Homarus americanus ) were tagged with sphyrion tags on two sites, one inside and the other at the entrance of St. Georges Bay, Nova Scotia. 290 (14.7%) were recovered after one year at liberty. In summary, 94.5% of those originally released inside the bay and 81.7% of those originally released at the bay entrance remained in or entered the bay over one year. All movement of the tagged lobsters was restricted to western St. George's Bay.

Note: This research paper came about in 1985 because fishermen in the St. Georges Bay area had expressed concern to Department of Fisheries and Oceans (DFO) over their lobster landings, which they believed had declined. They "requested that DFO investigate if a net lobster movement to a region outside of the bay may have caused this decline in the fishery. In 1986, the Invertebrates Research group undertook a tagging study in the Ballantyne's Cove, Cape George area of St. Georges Bay to determine the overall movement of lobsters in this area." This report summarizes the study and concludes that "unless there was an adverse environmental occurrence that would cause the lobsters to change their pattern of movement, the majority of lobsters within and in the proximity of St. Georges Bay appear to have movement restricted to the bay itself".