Summary The Quebec region of the Department of Fisheries and Oceans (DFO) is responsible for the assessment of several fish and invertebrate stocks exploited in the Estuary and the northern Gulf of St. Lawrence. The commercial catches sampling program is one of the sources of information used to complete these assessments. The data collected by this program, at wharf or at sea, offers among other things the advantage of a relatively large spatio-temporal coverage and provides some of the necessary knowledge to assess the demography and the structure of the exploited populations. This program is implemented by specialized DFO staff whose main mandate is to collect biological data on groundfish, pelagic fish and marine invertebrate species that are commercially exploited in the various marine communities. Data This dataset on the American plaice (Hippoglossoides platessoides) includes the metadata, sample weight, fish length, the sex and the number of specimen measured. This dataset covers the periods of 1989-2002, 2006-2008 and 2016-2018. In order to protect the confidentiality of the sources, some informations (such as those concerning the vessel) have been excluded and others (such as the date of capture) have been simplified. Entries where there was only one vessel in a fishing area for a given year were also excluded. Further information including the fishing areas coordinates can be found by clicking on the «Atlantic and Arctic commercial fisheries» and «Fishing areas» links below.

American Plaice otoliths are collected from scientific surveys, fisheries observers on fishing vessels and from scientific sampling of commercial fisheries. The otoliths collected are placed in paper envelopes, recorded and held in a climate-controlled storage facility. Age determination is performed yearly on the available samples. Digital images of each pair of otoliths collected are captured when possible. The information made available through this metadata record is the summary of otoliths 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 fish 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 ageing American Plaice exists and is used to calibrate the age readings obtained by the fisheries technicians that use the otoliths for age estimation. Digital images of the otoliths that are part of the reference collection are available and used for calibration and training purposes. The otolith images are also authoritatively annotated by fisheries technicians. PHYSICAL SAMPLE DETAILS: Fish otoliths. SAMPLING METHODS: American Plaice otoliths are obtained from fish specimens collected during research surveys, observer activities onboard commercial fishing vessels and during scientific sampling of commercial fisheries. The sagittal otolith is removed from sampled specimens, recorded, placed in a protective medium and held in a climate-controlled storage facility. Digital images of each pair of otoliths collected are captured when possible.

Tow, catch, and length frequency for fish caught during the August sentinel surveys in the southern Gulf of St. Lawrence (NAFO Division 4T). Abundance indices and spatial distribution patterns of commercial groundfish. Note: Due to delays caused by logistic complexities and Covid the project did not take place in 2020

PURPOSE: The primary objective of this survey is to obtain an index of the abundance of American lobster (Homarus Americanus) in the Northumberland Strait. This research survey also provides fisheries-independent information for all of the species captured by the trawl. DESCRIPTION: Catch weight, length frequencies, and biological information for crustaceans and fish caught during the annual July-August research vessel trawl survey in Northumberland Strait (NAFO Division 4T). Abundance indices and spatial distribution patterns of commercial and non-commercial crustaceans and other groundfish. PARAMETERS COLLECTED: The full catch is sorted to species, or lowest taxonomic group possible, and weighed. For lobster, carapace length, sex and carapace condition (i.e. stage of moult) are recorded. For female lobster, the presence or absence of eggs is noted and, starting in 2010, the stage of development of the eggs (i.e. new or old) when present was also recorded. Similarly, for crabs, the carapace width, sex and carapace condition (i.e. stage of moult) is recorded as is the presence or absence of eggs (for females). Fish sampling varied over the years but, starting in 2005, length has been recorded for all fish captured. For large catches, the complete catch is sorted and weighed, but sub-sampling, by species, is used for the other measurements. NOTES ON QUALITY CONTROL: Data are checked for irregularities. SAMPLING METHODS: The Northumberland Strait multi-species survey began in 2001 as a random stratified survey and now employs a random selection of sampling sites within the study area. Sampling is completed annually over a 4-week period in July and August. 110 stations are sampled in Northumberland Strait in water depths exceeding 4 m at Lowest Normal Tide. The survey has employed a 286 rockhopper trawl in all years from 2001 to 2018, except in 2010 and 2011 when a Nephrops trawl was used. In 2019, a newly designed trawl (termed the “Northumberland trawl”) was used in addition to the rockhopper trawl. The Northumberland trawl is similar to the rockhopper trawl but with a smaller footgear and smaller mesh sizes. At each station, the trawl is towed for a set period of time (recently 15 minutes with the rockhopper trawl and 10 minutes with the Northumberland trawl). USE LIMITATION: Please contact the data custodians before attempting to use this information in support of any kind of scientific analyses.