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GIGUERE, M, S. BRULOTTE, N. PAILLE, 2010. Croissance et mortalité de trois stocks de pétoncle dIslande (Chlamys islandica) mis en élevage à quelques sites de la Moyenne-Côte-Nord, Québec. Rapp. tech. can. sci. halieut. aquat., 2910, 67 p .
Growth and mortality of Iceland scallops were evaluated in reciprocal transfers between three stocks and sites (AN, QU, CHS) of the Middle North Shore to which three sites were added (CM, HAS and CHN) for captive breeding surveys with the CHS stock. After a year of breeding in pearl nets, the mortality rate of scallops ranged from 4 to 60%, this variable was significantly influenced by the site and stock. The average shell growth ranged from 1.7 to 7.6 mm. The site significantly impacted the final size of the scallops, while the stock and the site notably influenced the weight of the meat and gonad. The results show that the transfer of scallops from beds where growth is weak to more proficient sites helps accelerate their growth. However, the magnitude of the mortality observed could reduce the biological and economic benefits of such intervention. Viii
This document presents a review of the characteristics and the biology of this alga related to the east coast of North America and southern Gulf of St. Lawrence. A review of the ecological and economic impacts observed in other areas of the world and control methods is also presented. Codium fragile ssp. tomentosoides was first observed in the Magdelen Islands in 2003. A sampling program was conducted in this area in 2004 and 2005 to evaluate the current status of this species. Results showed that C. fragile ssp. tomentosoides is established in Great Entry harbour, particularly in Old Harry Bay and the mouth of Grosse Île Bay where important densities were observed. Environmental conditions in the Magdelen Islands may be favorable for an invasion by this alga. Ecological impacts on native communities following the arrival of C. fragile ssp. tomentosoides in the Magdelen Islands are unknown. Better control of potential vectors for introduction and dispersal and the development of monitoring and research programmes are needed to limit the spread of this species and better understand its ecological and economic impacts.
The green crab (Carcinus maenas) was identified in the Magdalen Islands for the first time in 2004. Seven crabs were observed by an eel fisherman near the Great Entry harbour, two of which were brought to the local Fisheries and Oceans Canada (DFO) office. Intensive sampling campaigns were undertaken in the summers of 2004 and 2005 to evaluate the regional status of this species. Two further crabs were caught by DFO during the 2004 campaign and none were captured in 2005. The geographic location and environmental conditions in the Magdalen Islands make the area at risk to invasion and monitoring should be continued. The potential ecological impacts of a C. maenas population becoming established in the Magdalen Islands are unknown. Monitoring of potential vectors of introduction, annual surveys, and the development of a rapid response plan are measures that must be put into place in order to limit the risks of introduction and subsequent impacts of a green crab invasion. The present document outlines the biology, ecology, and risks associated with the establishment of a green crab population. Specific recommendations with respect to control options for this species in the Magdalen Islands are also presented.
GIGUÈRE, M., S. BRULOTTE, N. PAILLE, J. FORTIN, 2005. Mise à jour des connaissances sur la biologie et l'exploitation de la mactre de l'Atlantique (Spisula solidissima) aux Îles-de-la-Madeleine. Rapp. tech. can. sci. halieut. aquat., 2587, 32 p .
The purpose of this document is to present the knowledge base on Atlantic surfclam (Spisula solidissima), Dillwyn 1817) biology, identify the species' spawning period in the Iles-de-la-Madeleine and provide an assessment of harvesting of this resource. The information that is presented comes from the literature, a 2003 study on the Atlantic surfclam reproductive cycle and an analysis of fishery statistics.
GENDRON, L., G. SAVARD, N. PAILLE, 2004. État des stocks de homard de la Côte-Nord du Québec (Zones 15, 16 et 18) en 2003. MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2004/062, 48 p .
In recent years, lobster landings from the North Shore accounted for 1 % to 2 % of total lobster landings in Quebec. Landings recorded in area 15 in 2003 totalled 30 t, which is equivalent to 2002 and to the 1984-1993 average (35 t). In area 16, landings totalled 8 t which is lower that the 1984-2002 average (13 t). Landings in area 18 are very low and have reached 2 t in 2003. Since 1993, the average annual CPUE observed during at-sea sampling in LFAs 15 and 16 ranged from 0.2 to 0.4 lobsters per trap. Mean CPUE recorded in 2003 reached 0.3 lobster per trap, which is slightly below the series average (0.33 lobster per trap). Mean size of commercial lobster was 87.5 mm in 2003 compared to 83.6 mm in 1997, before the increase in minimum legal size. Since 1998, minimum catch size was increased by 4 mm. Although size frequency distributions occasionally show a few modes in the larger size groups, they nevertheless indicate relatively high exploitation rates. No jumbo lobsters (≥127 mm CL) were found in samples in 2003. Over the years, berried females have been seen in catches, mainly at the end of the fishing season, in proportions that ranged from 5 % to 35 %. However, the abundance is generally low and between 1993 an 2003, an average of only 24 berried females was sampled each year. There was a slight increase in their proportion in the past three years. The average size of berried females is about 90 mm. Observations made in 2003 in LFA 15 showed that females reach sexual maturity at approximately 93 mm. Egg-per-recruit production was not calculated specifically for North Shore sectors. Nevertheless, because of the large size at sexual maturity and high exploitation rates, the egg production per recruit level is thought to be low compared with a non-harvested lobster stock. Consequently, it is recommended that minimum catch size continue to be increased, in order to increase egg production.
THERRIAULT, J.-C., N. PAILLE, 2002. Les processus océanographiques dans l'estuaire et le golfe. Saint-Laurent Vision 2000 (Suivi de l'état du Saint-Laurent, 21) 8 p. .
THERRIAULT, J.-C., N. PAILLE, 2002. Oceanographic processes in the Estuary and Gulf. St. Lawrence Vision 2000 (Monitoring the state of the St. Laurence River, 21) 8 p. .
PAILLE, N., L. GENDRON, 2001. Conception et mise en place de récifs artificiels pour le homard (Homarus americanus) : revue des essais et recommandations. Rapp. can. ind. sci. halieut. aquat., 261, 43 p .
There is a growning interest for artificial reefs as they may represent a valid option to compensate for the loss or perturbation of lobster habitats. Building artificials reefs requires however a good knowledge of the biological characteristics and behavior of the target species, to be able to answer its needs and facilitate its establishment on the reef. Moreover a good knowledge of the surrounding environment is essential since the prevailing conditions will ultimately determine the performance and perennity of the reef. In this report, we describe 7 reefs that were built in the last 35 years. The purpose is to highlight the important aspects that should be taken into consideration in the future for the conception and deployment of artificial reefs for lobster. In the light of the examples, we present a discussion and some recommendations on the elements that should be addredded for the choice of the reef site, the building of the reef and for the performance evaluation, to determine if the initial goals were reached. Discussion on the choice of the reef site is based on the following six elements: the physical and chemical conditions on the site (temperature, salinity, oxygen, water and sediment contamination), the dynamics of prevailing water currents at small and large scales, the dynamincs of the substrate (erosion and sedimentation), the characteristics of the substrate, the site depth and the presence of conspecifics. The elements considered important for the conception and building of the reef that are discussed include the type of building material, the dimensions of the reefs and their spatial arrangement, the number, form, dimension and orientation of the shelters on the reef and the colonisation of the reef by other algal and animal species. The discussion on reef performance evaluation focuses on the variables to sample, the sampling techniques and strategies, and the sampling effort, depending on the type of reef, initial goals and the degree of precision required. It is certainly possible to build artificials reefs that are efficient for lobsters. These must provide a long-term suitable habitat adapted to the needs of the successive benthic stages of the lobster. The success of any artificial reef project relies on a responsible and effective planning and requires a scientifically rigourous assessment of reef performance in meeting its goal.
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