Bibliography of the Maurice Lamontagne Institute

Jérôme BENOÎT

LAVOIE, D., Y. SIMARD, J. BENOÎT, P. LAROUCHE, B. THIBEAULT, 1996. Distribution des masses d'eau à la tête du chenal laurentien dans l'estuaire du Saint-Laurent aux étés 1994 et 1995. Rapp. tech. can. hydrogr. sci. océan., 176, 126 p .

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Satellite thermal images and temperature and salinity profiles, taken during the summers of 1994 and 1995, are used to describe the water masses at the head of the Laurentian channel. The three typical water masses of this system; the surface, the intermediate and the bottom layers showed : 1) a thinning and an elevation of the cold intermediate layer at the end of the summer, associated with a thickening of the bottom layer, 2) a colder intermediate layer in 1995, 3) a recurrent spatial structure, characterized by a convergence of the cold intermediate layer off Les Escoumins. Upwelling of intermediate cold waters at the head of the Laurentian channel was observed most of the time, as well as many fronts associated with its contact with adjacent waters from the Saguenay and the upper estuary. Our results suggest that the intensity and occurrence of these phenomena were modulated by the fortnightly tidal cycle and by the wind which regularly generated cold water upwelling along the north shore.

SIMARD, Y., J. BENOÎT, M. DESGAGNÉS, L. SAVARD, S. HURTUBISE, 1992. Atlas de la pêche à la crevette nordique (Pandalus borealis) dans le golfe du Saint-Laurent 1982-1991 : captures, effort, rendement, saison ; Atlas of the northern shrimp (Pandalus borealis) fishing in the Gulf of St. Lawrence 1982 - 1991 : catch, effort, yield, season. Rapp. tech. can. sci. halieut. aquat. ; Can. Tech. Rep. Fish. Aquat. Sci., 1900, 73 p .

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The information gathered in the fishing logbooks of shrimp trawlers operating in the Gulf of St. Lawrence during 1982 to 1991 inclusively is used to generate an atlas of this important fishing activity. The data are first checked for erroneous or incomplete records. The proportion of available valid information compared to the landings at the fish plants is calculated for each of the 5 fishing management units. Simple maps of weighted catch, of available effort and yields are then computed per year and per season; March-May and June– December. Maps of best significant annual yields, based on the available data, are then calculated. Summary maps joining the information of all years follow. They are maps of : total catch, mean catch and its standard deviation, for the whole fishing period or per season; mean monthly relative catch; weighted mean yield and its standard deviation over the whole fishing period or per season.

SIMARD, Y., J. BENOÎT, 1992. Geostatistical estimations and maps of the Northern shrimp biomass in the Gulf of St. Lawrence from 1990 to 1992, by size group and for all sizes together. CAFSAC Res. Doc., 92/96, 26 p .

Stationary geostatistical methods are used to compute estimates and map the fall biomass of northern shrimp (Pandalus borealis) in the Gulf of St. Lawrence in 1990, 1991 and 1992. Estimates and maps are computed separately by size groups and globally for all sized. The samples used were collected during daylight from the FRV/Alfred-Needler with a shrimp bottom trawl. Isotropic models of the spatial variability are estimated form the data, for each year separately and for all years together. The all-years models were less erratic than the annual models and were used for estimating the biomass and its confidence interval. The global estimates are computed for the fishing grounds deeper than 150 m, separately for four zones corresponding to the management units of the fishery. Global estimates showed that the Gulf biomass below the 150 m depth contour were 63.7, 69.9 and 47.5 kt for 1990, 1991 and 1992 respectively. Local variations occurred, some zones increased their shrimp biomass while it decreased in others. Similarly, the global biomass by size groups exhibited a large variability in its distribution and abundance pattern in time and space. The notable decrease of global biomass in 1992 was the fact of a weakening of the oldest cohorts (female) only, in the two zones of Esquiman channel and Sept-Îles region.