SCUBA-Based Assessment of Lobster Density and Structure in the Southern Gulf

PURPOSE: The SCUBA survey was designed to assess the density of small lobsters (1-3 years of age) in rocky reefs, in the nearshore habitat.

DESCRIPTION: Total number of transects surveyed and total number of lobsters measured for each site in each year. There are some sites that do not have any coordinates identified, therefore these have not been included in the Web Map Services (WMS).

PARAMETERS COLLECTED: Size measurement (biological); species counts (ecological); substrate (geological)

SAMPLING METHODS: Transects are laid out from a small vessel using buoys, anchors, and a 100 m leaded rope along the bottom, marked at 5 m intervals. A strip transect survey method is used whereas two divers sample a 1 or 2 m strip (dependent on lobster density) alongside either side of the leaded rope. All captured lobsters are measured (carapace length) and all lobsters of ≥20 mm carapace length are sexed. The complexity and suitability of the habitat is assessed in the 5 m sections (e.g. rocky reefs, sand, large boulders).

USE LIMITATION: To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.

Data and Resources

Additional Info

Field Value
Last Updated April 17, 2026, 18:37 (UTC)
Created April 17, 2026, 18:37 (UTC)
contact_email DFO.GLFCSA-CASGLF.MPO@dfo-mpo.gc.ca
contact_person {"en": "Government of Canada; Fisheries and Oceans Canada", "fr": "Gouvernement du Canada; Pêches et Océans Canada"}
criticality_level []
data_dictionary EPSG:4326,http://www.epsg-registry.org,
geographic_scope []
open_canada_collection fgp
open_canada_date_modified 2025-03-24 00:00:00
open_canada_date_published 2022-05-31 00:00:00
open_canada_keywords {"en": ["SCUBA (observations and/or sampling)", "Visual Counts/Observations", "Crustaceans", "Decapods", "Homarus americanus", "Crustaceans", "Gulf of St. Lawrence"], "fr": ["PLONGÉE SOUS-MARINE (observations et/ou échantillonnage)", "Comptages visuels/observations", "crustacés", "décapodes", "Homarus americanus", "Crustacé", "Golfe du Saint-Laurent"]}
open_canada_subject ["nature_and_environment", "science_and_technology"]
sensitivity_level unrestricted
title_fr Évaluation par SCUBA de la densité et de la structure des homards dans le sud du Golfe
update_frequency P1Y