Since 1991, an annual fishery-independent acoustic survey of early fall (September-October) concentrations of Herring has been conducted in the sGSL. The standard annual survey area occurs in the 4Tmno areas where both NAFO Div. 4T Herring spawning components aggregate in the fall. The survey uses a random stratified design of parallel transects within predefined strata. Surveys are conducted at night and use two vessels: an acoustic vessel to quantify the fish schools biomass using a hull-mounted 120 KHz split-beam transducer, and a fishing vessel to sample aggregates of fish with a pelagic trawl (details in LeBlanc et al. 2015; see also LeBlanc and Dale 1996). Trawl samples are used to separate the estimated biomass by spawning component and age, determine species composition, and size distribution for the estimation of the target strength (LeBlanc and Dale 1996; LeBlanc et al. 2015). A standardized abundance index is generated from this acoustic survey. This index includes catch-at-age data since 1994. This survey also provides the age-disaggregated acoustic abundance index for ages 2 to 10 for spring spawners and fall spawners.

In 2015, a spawning ground acoustic survey that follows the design of the fishery-independent acoustic survey was initiated. This survey is the result of a partnership between DFO and fishery associations. The survey design uses random parallel transects within predefined strata. Surveys are conducted by fishermen in the fall fishing season according to protocols developed by DFO. The survey is conducted at night, during the weekend fishery closures except in Herring fishing area 16C and 16E in 2015 to 2017, where this region didn’t have weekend closures. The spawning ground acoustic survey is meant to provide a nightly estimate of spawning biomass among regions. It is analyzed in the same manner as the fishery-independent acoustic survey. The catches from the experimental nets are used to calibrate the spawning group specific target strength in order to obtain the nightly estimates of spawning biomass.

Atlantic herring NAFO 4T commercial landings data. Landings (in metric tons) per year, per stock (spring spawners and fall spawners), per fishing season (spring and fall) and per gear (fixed and mobile). Two fish samples are taken per week per herring fishing area to determine stock identification (spring or fall spawners). Daily landings data are obtained from DFO Statistics Branch. Stock (spring or fall spawner) data are gathered from port sampling.

The acoustic trawl database for Lynn Canals echo-trawl survey was conducted from 2001 to 2004 throughout southern Lynn Canal in southeast Alaska. Acoustic surveys were conducted one day per month and trawl surveys were conducted every 3 months to verify acoustic signals and collect biological data. This study was conducted to study the relationship between Steller sea lions (Eumetopias jubatus) and their prey. Additional acoustic surveys were conducted throughout the winter of 2004 to 2005 on 6 consecutive days once a month in order to study forage fish hots spots. Acoustic equipment were calibrated before every trawl survey. Acoustic data were analyzed by the same qualified acoustician throughout the surveys duration with calibrations entered into the analytical software after each calibration. Trawls were used to identify the fish species associated with a specific acoustic signal and to get length weight data per species. Trawl data were also used to enumerate and identify all nekton found within the study area and to generate length frequencies, species composition and abundance by species and season. The acoustic data was use to generate biomass estimates for Pacific herring and walleye pollock. Longlines were deployed to better identify and enumerate the benthic species not usually caught in pelagic trawls.

Fecundity of Atlantic herring (Clupea harengus) was estimated within five spawning areas (German Bank, Scots Bay, Seal Island, Southern Shore Nova Scotia, and Eastern Shore Nova Scotia) in Northwest Atlantic Fisheries Organization (NAFO) areas 4WX in 2019 and 2020. The objective of this project was to describe the fecundity-at-size (weight, length, and age) relationships among spawning grounds, compare these relationships to historical fecundity-at-size relationships, and assess the influence of changes in weight-at-age and fecundity over time to the reproductive potential of a unit of spawning stock biomass. Cite this data as: Barrett T. Data of: Fecundity of Herring in Divisions 4WX. Published: September 2021. Population Ecology Division, Fisheries and Oceans Canada, St. Andrews, N.B. https://open.canada.ca/data/en/dataset/e39b1318-c9f7-4686-b5e5-7d838c8ac99a

Variable mesh gillnets were used to evaluate the abundance of young of the year sablefish during 1995-2002. Data include. Vessel, cruise, station. Species caught, and lengths of fish caught. The data were collected to be able to forecast year-class strength of sablefish.

The Department of Fisheries established a survey of demersal juvenile Atlantic cod (*Gadus morhua*) in the nearshore (<10 m deep) in 1959. This survey aimed to characterize the distribution and abundance of juvenile Atlantic cod and was based upon Norway's Flodevigen sampling program which has been conducted continuously since 1919. A 25 m seine was used to sample juvenile Atlantic cod nursery locations on the Avalon Peninsula and Northeast coast of the island of Newfoundland in September and October. The survey continued until 1964 and became known as the Fleming survey, after original initiator Alistair Fleming. The survey was reinstated by Memorial University of Newfoundland from 1992 to 1997. Multiple tows were conducted at a subset of the original 55 Fleming sites located in St. Mary's Bay, Trepassey Bay, the Southern Shore, Conception Bay, Trinity Bay, Bonavista Bay, Gander Bay, New World Island, Fortune Harbour, Badger Bay, Halls Bay and Green Bay. This data set includes several different subsets, some of which span both Fleming Survey periods (1959-1964 and 1992-1997): I. JuvCodCatch60s90s: Catches of juvenile Atlantic cod (1959-1964, 1992-1997) from the first two consecutive tows at each site. This is a summary based on JuvCodLengths90s and FlemingSurveyData60s; II. JuvCodLength90s: Lengths of all individual juvenile Atlantic cod caught for each site (1992-1997); III. SiteEnvData60s90s: Station data for Fleming data 1992-1997; IV. FlemingSurveyData60s: Fleming survey data from 1959-1964 (note there are three record types pertaining to: station data "type 1"; general species catch data including juvenile Atlantic cod grouped by age class ("1+", "Zeroes", and "Total") "type 2; and juvenile Atlantic cod (species 223) listed in length bins "type 3"; and V. FlemingBycatch60s92to96: Bycatch data from 1959-1964 & 1992-1996 from first two tows at each site. This is a summary based partly on the FlemingSurveyData60s set.

PURPOSE: These data have been updated following a Canadian Science Advice Secretariat (CSAS) Regional Science Advisory Process. Associated publications are available in the citation section below or will be posted on the Fisheries and Oceans Canada (DFO) Science Advisory Schedule as they become available. DESCRIPTION: Atlantic herring NAFO 4T biomass estimates for both spring and fall stock components. Values are provided in kilotons (kt) alongside with confidence intervals 50% (spring) and 95% (spring and fall). USE LIMITATION: To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.