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.

Each summer, environmental community groups collect important data to determine if groupings of fish, shrimp and crab – what is called a community- can be used as an indicator of the health status of bays and estuaries. Sampling was conducted from May through September for the first years then from June through August. In 2018 and 2019, the sampling was conducted just once in each estuary. Community group members and staff sample six stations once a month in their designated estuary. Fish, shrimps and crabs are collected with a beach seine net and later released live back to the water once identified and counted. From this, the community groups provide important information to Fisheries and Oceans Canada, including: - identification and numbers of fish, shrimp and crab species; - water conditions and samples; - information on aquatic plants; - sediment samples. With this information, Fisheries and Oceans Canada scientists working with government agencies and universities can conduct analyses to determine the suitability of indicators to assess the health of bays and estuaries. PARAMETERS COLLECTED: Parameters: abundance, species richness, species developmental stage (young-of-the-year or adult), water temperature, water salinity, water dissolved oxygen, dissolved inorganic nutrient (nitrate, nitrite, phosphate), sediment % organic content, sediment % humidity content and sediment mean grain size, % submerged aquatic vegetation cover NOTES ON QUALITY CONTROL: Data entry into Excel and first quality control verification is done by CAMP summer students. A second quality control verification is done by DFO staff. See publ # 2823 attached to this record. In 2018, the historical data was migrated into a relationship database. From this year on, annual data will be entered into the database using a custom application. The application front end has numerous QC elements built-in. SAMPLING METHODS: Please see the following URL for sampling details: http://www.dfo-mpo.gc.ca/Library/319437.pdf