Skate vertebrae are collected from the annual September scientific survey in the southern Gulf of St. Lawrence. Skate spines are collected and frozen during the survey, and the vertebrae are processed in the laboratory at a later stage. Age determination is performed episodically on the available samples. The information made available through this metadata record is the summary of skate vertebrae present in the collection at the Gulf Fisheries Centre in Moncton, NB, Canada. There is additional information of observed sex, length, weight and age information of skate specimens made by trained Fisheries and Oceans Canada technicians that can be made available upon request. PARAMETERS COLLECTED: length (biological), age (biological) NOTES ON QUALITY CONTROL: A reference collection for skate vertebrae exists and is used to calibrate the age readings by the fisheries technicians that use the vertebrae for age estimation. PHYSICAL SAMPLE DETAILS: Skate vertebrae SAMPLING METHODS: Vertebrae are obtained from skate specimens collected on the annual September scientific survey in the southern Gulf of St. Lawrence. Skate spines are collected and frozen during the survey, and the vertebrae are processed in the laboratory at a later stage. Age determination is performed episodically on the available samples.

Spatial distribution of the Smooth Skate presence expressed by catch weight based on the annual Department of Fisheries and Oceans (DFO) groundfish research surveys realised between 2004 and 2010. Catch data (kg/nautical mile) were aggregated by 100 km² cells. They are derived from processed data used for the production of: Chouinard, P-M., J-D. Dutil, S. Proulx, D. Borcard and J. Crocker. 2014. A spatial approach to matching marine fish diversity and abundance with habitat features. Hydrobiologia. Volume 734, Issue 1: 39-55. Associated publication: Dutil, J.-D., Proulx, S., Chouinard, P.-M., and Borcard, D. 2011. A hierarchical classification of the seabed based on physiographic and oceanographic features in the St. Lawrence. Can. Tech. Rep. Fish. Aquat. Sci. 2916: vii + 72 pages. Purpose Since 1990, the Department of Fisheries and Oceans has been conducting an annual multidisciplinary survey in the Estuary and northern Gulf of St. Lawrence using a standardized protocol. In the southern Gulf of St. Lawrence, these bottom trawl surveys has been carrying out each September since 1971. These missions are an important source of information about the status of the marine ressources. The objectives of the surveys are multiple: to estimate the abundance and biomass of groundfish and invertebrates, to identify the spatial distribution and biological characteristics of these species, to monitor the biodiversity of the Estuary and Gulf and finally, to describe the environmental conditions observed in the area at the moment of the sampling. The southern Gulf surveys are realized using the following standardized protocol: Hurlbut,T. and D.Clay (eds) 1990. Protocols for Research Vessel Cruises within the Gulf Region (Demersal Fish) (1970-1987). Can. MS Rep. Fish. Aquat. Sci. No. 2082: 143p. The sampling protocols used for the Estuary and northern Gulf surveys are described in details in the following publications: Bourdages, H., Archambault, D., Bernier, B., Fréchet, A., Gauthier, J., Grégoire, F., Lambert, J., et Savard, L. 2010. Résultats préliminaires du relevé multidisciplinaire de poissons de fond et de crevette d’août 2009 dans le nord du golfe du Saint-Laurent. Rapp. stat. can. sci. halieut. aquat. 1226 : xii+ 72 p. Bourdages, H., Archambault, D., Morin, B., Fréchet, A., Savard, L., Grégoire, F., et Bérubé, M. 2003. Résultats préliminaires du relevé multidisciplinaire de poissons de fond et de crevette d’août 2003 dans le nord du golfe du Saint-Laurent. Secr. can. consult. sci. du MPO. Doc. rech. 2003/078. vi + 68 p. Annual reports are available at the Canadian Science Advisory Secretariat (CSAS), (http://www.dfo-mpo.gc.ca/csas-sccs/index-eng.htm).

PURPOSE: The research survey provides a fisheries-independent source of information about all marine living organisms that are captured by the fishing trawl used to obtain samples in the southern Gulf of St. Lawrence. DESCRIPTION: Tow, catch, length frequency, and biological information for fish caught during the annual September research vessel trawl surveys in the southern Gulf of St. Lawrence (NAFO Division 4T). Abundance indices and spatial distribution patterns of commercial and non-commercial groundfish. The catch data that appear in this dataset SHOULD NOT BE USED FOR ECOLOGICAL ANALYSES INVOLVING CATCH RATES. Important factors such as vessel, fishing gear and diurnal periods must be accounted for to use these data in analyses. Please contact the data custodians if you are interested in using this data for any kind of ecological analyses involving catch rates. PARAMETERS COLLECTED: abundance estimates (ecological); distribution (ecological); species counts (ecological); gear (fishing); vessel information (fishing); point (spatial) NOTES ON QUALITY CONTROL: Scientific names listed in the survey species list have been mapped to recognized standards - marine taxa have been mapped to the World Register of Marine Species (WoRMS) using their online taxon match tool. All sampling locations were plotted on a map to perform a visual check confirming that the latitude and longitude coordinates were within the described sampling area. In 2003, because of a fire aboard the Alfred Needler, the Wilfred Templeman was used for the survey. However, no comparative fishing experiments have been conducted between the Alfred Needler and the Wilfred Templeman. We are therefore unable to integrate the indices derived for 2003 to the remainder of the survey time-series. SAMPLING METHODS: Sampling Method: Consult the "Protocols for research vessel cruises within the Gulf Region (dermersal fish) (1970-1980)" report, link provided in the citations list. USE LIMITATION: To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.