Dataset: herring spawng grounds_fish size
Deployment: NEC-JA2005-1

Inshore Gulf of Maine Acoustic Survey of Atlantic Herring Sentinel Spawning Grounds: biological sample data: size, sex, maturity

Chief Scientist:

Dr John Annala (Gulf of Maine Research Institute, GMRI)

Scientist:

Dr Matthew Cieri (Maine Department of Marine Resources, Maine DMR)

Patrick Sullivan (Cornell University, Cornell)

Captain:

Lendell Alexander

Mark Bichrest

Alden Leeman, III

Technician:

Shale Rosen (Gulf of Maine Research Institute, GMRI)

Daniel J Salerno (Gulf of Maine Research Institute, GMRI)

BCO-DMO Data Manager:

Nancy Copley (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

Northeast Consortium: Cooperative Research (NEC-CoopRes)

Current State:

Final no updates expected

Version Date:

2011-10-20

Data URL:

https://osprey.bco-dmo.org/dataset-deployment/451665/data

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Description

Inshore Gulf of Maine Acoustic Survey of Atlantic Herring Sentinel Spawning Grounds

Atlantic Herring biological sample data: size, sex, maturity

Methods & Sampling

Dataset acquisition description

Project reports:

Herring Acoustic Survey (Year 6) Final Report - July 2007
Herring Survey Mid-Year Progress Report - December 2006

"The temporal and special characteristics of spawning herring aggregations in coastal Gulf of Maine waters have been studied during the fall since 1998. The program has attempted to estimate the biomass of herring spawning in these waters during the fall months to establish an index of spawning stock biomass. Surveys have been conducted from Cape Ann, Massachusetts to Cutler, Maine. Each year, techniques have been refined for implementing acoustic surveys and collecting representative biological samples on fishing vessels.

In March 2005, the Northeast Consortium funded and facilitated an independent peer review, which concluded that acoustic surveys are an appropriate way to survey herring in this area and recommended continuation of the project. It also recommended that future surveys focus on estimating biomass using a broad-scale systematic survey approach, as well as developing an annual "sentinel" acoustic survey of the important spawning grounds. This project continues with additional funds from the Northeast Consortium granted in 2005. The panel's recommendations are being incorporated into the work, with surveys focused on identifying and quantifying "sentinel" spawning grounds." extracted from: Summary of Completed Cooperative Research Projects Funded by the Northeast Consortium, September 2006

Sub Areas

Each survey leg was apportioned into geographical sub areas prior to data analysis in order to allow for more precise target strength calculations for individual aggregations of fish. For any given leg, the observed distribution of Atlantic herring as well as the locations and distribution of biological sample tows were used to define between two and four unique sub areas for the leg. Data from all biological sample tows conducted within a given sub area were combined before calculating a target strength. This process should reduce the variance within each sub area biomass estimate and accounted for multiple sampling of the same fish aggregations.

Data Processing Description

Dataset Processing Description

When significant aggregations of fish were detected acoustically, the midwater trawl was set to confirm species identity and to collect approximately 100 individual Atlantic herring. Tows were conducted along the transect line after passing over the fish aggregations. Tow times were generally short in duration (10 - 20 minutes); just long enough to collect the necessary samples. All herring samples were frozen at sea for further laboratory analysis.

Back in the laboratory, herring samples were thawed out for examination. Natural length measurements were taken to the nearest 5 mm, total weight to the nearest 0.1 g, gonad weight to the nearest 0.1 g, sex and International Commission for the Northwest Atlantic Fisheries (ICNAF) gonad development stage (Table 3). In order to account for freezing and thawing of herring samples, length measurements were corrected using Maine Department of Marine Resources' correction equation:

Lmm = 4.1825 + 1.0051 * [Frozen Sample Length (mm)].

Stage Description and Criteria
ICNAF Atlantic herring gonad development stages (from Burnett et al., 1989).

I
Immature: testes and ovaries very small, threadlike, 2 - 3 mm broad; testes grayish
white or brownish red; ovaries pinkish or wine red.
II
Immature fish that will spawn next year: testes and ovaries small, 3 - 8 mm broad;
testes reddish or grayish brown; ovaries orange-red; eggs visible only with
microscope.
III
Ripening, early stage: testes and ovaries occupy about half of ventral cavity, 1 - 2
cm broad; testes grayish or brownish red; ovaries orange-red; eggs small, but visible
and granular.
IV
Ripening, mid-stage: testes and ovaries almost as long as body cavity; testes reddish
yellow with blood vessels clearly visible; ovaries orange-red or pale yellow-red; eggs
larger, opaque with only a few clear.
V
Ripe: testes and ovaries fill body cavity; milt and eggs do not flow, but can be
extruded by pressure; testes yellowish white or milk white with no reddish color and
blood vessels not visible; ovaries yellowish; eggs large and mostly clear.
VI
Spawning: testes and ovaries ripe and emptying; milt and eggs flow freely; testes
white or pale yellowish white with no blood vessels visible; ovaries yellowish; eggs
large and clear.
VII
Spent: testes and ovaries baggy, flabby and bloodshot; testes empty or with residual
milt; ovaries empty or with few residual eggs.
VIII
Resting: testes and ovaries firm and larger than in Stage II; walls striated with blood
vessels prominent; testes brownish red; ovaries wine red; eggs not visible to naked
eye.

More information about this dataset deployment

Funding

Award Number	Funding Source
NA05NMF4721057	National Oceanic and Atmospheric Administration

Instruments

Midwater Trawl

Supplied Description:

17 x 15 fm midwater trawl net with a 17/8" mesh codend. The net included
a trawl monitoring system which relayed real time height of headrope from the sea bottom to aid with the collection of herring samples.

Instrument Type

Generic Name: Midwater Trawl

Acronym: TrawlMid

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/23/

Generic Description:

A mid-water or pelagic trawl is a net towed at a chosen depth in the water column to catch schooling fish such as herring and mackerel. Midwater trawl nets have very large front openings to herd schooling fish toward the back end where they become trapped in the narrow "broiler". The sides of the deployed net are spread horizontally with two large metal foils, called "doors," positioned in front of the net. As the trawler moves forward, the doors, and therefore the net, are forced outward, keeping the net open.
This instrument designation is used when specific make and model are not known.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
lat	latitude; North is positive	decimal degrees	lat
lon	longitude; East is positive	decimal degrees	lon
sex	sex of specimen		sex
yrday_local	local day and decimal time, as 326.5 for the 326th day of the year, or November 22 at 1200 hours (noon)		yrday_local
time_local	local time		time_local
year	year of sampling		year
length	length of	mm	fish_len
weight	weight of fish	grams	weight_g
Maturity_ICNAF	see processing description under 'Stage Description and Criteria'		stage
weight_gonad	weight of gonads	grams	weight
visit	datafile name, comprised of date of sample plus A, B, C if there are several subfiles.		no_bcodmo_term

Database

Contribute Data

Dataset: herring spawng grounds_fish size
Deployment: NEC-JA2005-1

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: herring spawng grounds_fish sizeDeployment: NEC-JA2005-1

Dataset acquisition description

Dataset Processing Description

Dataset: herring spawng grounds_fish size
Deployment: NEC-JA2005-1