U. S. DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

National Marine Fisheries Service

Northeast Region

Northeast Fisheries Science Center

Woods Hole, Massachusetts

December 2001

NOAA Technical Memorandum NMFS-NE-166

Report on the

Third Northwest Atlantic

Herring Acoustic Workshop,

University of Maine Darling Marine Center,

Walpole, Maine, March 13-14, 2001
154. Report of the Joint Scientific Review Group Workshop, April 13-14, 1999, Seattle, Washington. By Richard

L. Merrick, compiler. November 1999. v + 22 p., 3 figs., 6 tables, 5 app. NTIS Access. No. PB2000-105393.

155. Food of Northwest Atlantic Fishes and Two Common Species of Squid. By Ray E. Bowman, Charles E.

Stillwell, William L. Michaels, and Marvin D. Grosslein. January 2000. xiv + 138 p., 1 fig., 7 tables, 2 app. NTIS Access.

No. PB2000-106735.

156. Proceedings of the Summer Flounder Aging Workshop, 1-2 February 1999, Woods Hole, Massachusetts. By

George R. Bolz, James Patrick Monaghan, Jr., Kathy L. Lang, Randall W. Gregory, and Jay M. Burnett. May 2000. v

+ 15 p., 5 figs., 5 tables. NTIS Access. No. PB2000-107403.

157. Contaminant Levels in Muscle of Four Species of Recreational Fish from the New York Bight Apex. By Ashok

D. Deshpande, Andrew F.J. Draxler, Vincent S. Zdanowicz, Mary E. Schrock, Anthony J. Paulson, Thomas W. Finneran,

Beth L. Sharack, Kathy Corbo, Linda Arlen, Elizabeth A. Leimburg, Bruce W. Dockum, Robert A. Pikanowski, Brian

May, and Lisa B. Rosman. June 2000. xxii + 99 p., 6 figs., 80 tables, 3 app., glossary. NTIS Access. No. PB2001-107346.

158. A Framework for Monitoring and Assessing Socioeconomics and Governance of Large Marine Ecosystems.

By Jon G. Sutinen, editor, with contributors (listed alphabetically) Patricia Clay, Christopher L. Dyer, Steven F.

Edwards, John Gates, Tom A. Grigalunas, Timothy Hennessey, Lawrence Juda, Andrew W. Kitts, Philip N. Logan, John

J. Poggie, Jr., Barbara Pollard Rountree, Scott R. Steinback, Eric M. Thunberg, Harold F. Upton, and John B. Walden.

August 2000. v + 32 p., 4 figs., 1 table, glossary. NTIS Access. No. PB2001-106847.

159. An Overview and History of the Food Web Dynamics Program of the Northeast Fisheries Science Center,

Woods Hole, Massachusetts. By Jason S. Link and Frank P. Almeida. October 2000. iv + 60 p., 20 figs., 18 tables,

1 app. NTIS Access. No. PB2001-103996.

160. Measuring Technical Efficiency and Capacity in Fisheries by Data Envelopment Analysis Using the General

Algebraic Modeling System (GAMS): A Workbook. By John B. Walden and James E. Kirkley. October 2000. iii

+ 15 p., 9 figs., 5 tables. NTIS Access. No. PB2001-106502.

161. Demersal Fish and American Lobster Diets in the Lower Hudson - Raritan Estuary. By Frank W. Steimle,

Robert A. Pikanowski, Donald G. McMillan, Christine A. Zetlin, and Stuart J. Wilk. November 2000. vii + 106 p., 24

figs., 51 tables. NTIS Access. No. PB2002-105456.

162. U.S. Atlantic and Gulf of Mexico Marine Mammal Stock Assessments – 2000. Edited by Gordon T. Waring,

Janeen M. Quintal, and Steven L. Swartz, with contributions from (listed alphabetically) Neilo B. Barros, Phillip J.

Clapham, Timothy V.N. Cole, Carol P. Fairfield, Larry J. Hansen, Keith D. Mullin, Daniel K. Odell, Debra L. Palka,

Marjorie C. Rossman, U.S. Fish and Wildlife Service, Randall S. Wells, and Cynthia Yeung. November 2000. ix + 303

p., 43 figs., 55 tables, 3 app. NTIS Access. No. PB2001-104091.

163. Essential Fish Habitat Source Document: Red Deepsea Crab, Chaceon (Geryon) quinquedens, Life History

and Habitat Characteristics. By Frank W. Steimle, Christine A. Zetlin, and Sukwoo Chang. January 2001. v + 27

p., 8 figs., 1 table. NTIS Access. No. PB2001-103542.

164. An Overview of the Social and Economic Survey Administered during Round II of the Northeast

Multispecies Fishery Disaster Assistance Program. By Julia Olson and Patricia M. Clay. December 2001. v + 69

p., 3 figs., 18 tables, 2 app. NTIS Access. No. PB2002-105406.

165. A Baseline Socioeconomic Study of Massachusetts’ Marine Recreational Fisheries. By Ronald J. Salz, David

K. Loomis, Michael R. Ross, and Scott R. Steinback. December 2001. viii + 129 p., 1 fig., 81 tables, 4 app.

Recent Issues in This Series:
NOAA Technical Memorandum NMFS-NE-166

This report series represents a secondary level of scientifiic publishing. All issues

employ thorough internal scientific review; some issues employ external scientific

review. By design, reviews are transparent collegial reviews, not anonymous peer

reviews. All issues may be cited in formal scientific communications.

U.S. DEPARTMENT OF COMMERCE

Donald L. Evans, Secretary

National Oceanic and Atmospheric Administration

Conrad C. Lautenbacher, Jr., Administrator

National Marine Fisheries Service

William T. Hogarth, Assistant Administrator for Fisheries

Northeast Region

Northeast Fisheries Science Center

Woods Hole, Massachusetts

December 2001

William L. Michaels1,3, Editor and Coconvenor,

and Philip Yund2,4, Coconvenor

Report on the

Third Northwest Atlantic

Herring Acoustic Workshop,

University of Maine Darling Marine Center,

Walpole, Maine, March 13-14, 2001

Postal Addresses: 1National Marine Fisheries Service, Woods Hole Laboratory,166 Water St., Woods Hole, MA

02543-1026; 2

National Science Foundation, Biological Oceanography Program, 4201 Wilson

Blvd., Arlington, VA 22230

E-mail Addresses: 3William.Michaels@noaa.gov; 4

pyund@nsf.gov
Editorial Notes

Species Names: The NEFSC Editorial Office’s policy on the use of species names in all technical communications is

generally to follow the American Fisheries Society’s lists of scientific and common names for fishes (i.e., Robins et al.

1991a), mollusks (i.e., Turgeon et al. 1998b), and decapod crustaceans (i.e., Williams et al. 1989c), and to follow the

Society for Marine Mammalogy's guidance on scientific and common names for marine mammals (i.e., Rice 1998d).

Exceptions to this policy occur when there are subsequent compelling revisions in the classifications of species, resulting

in changes in the names of species (e.g., Cooper and Chapleau 1998e

, McEachran and Dunn 1998f).

Statistical Terms: The NEFSC Editorial Office’s policy on the use of statistical terms in all technical communications

is generally to follow the International Standards Organization’s handbook of statistical methods (i.e., ISO 1981g

).

Internet Availability: This issue of the NOAA Technical Memorandum NMFS-NE series is being copublished, i.e., as

both a paper and Web document. The Web document, which will be in HTML (and thus searchable) and PDF formats,

can be accessed at: http://www.nefsc.noaa.gov/nefsc/publications/.

a

Robins, C.R. (chair); Bailey, R.M.; Bond, C.E.; Brooker, J.R.; Lachner, E.A.; Lea, R.N.; Scott, W.B. 1991. Common and scientific names of fishes

from the United States and Canada. 5th ed. Amer. Fish. Soc. Spec. Publ. 20; 183 p.

b

Turgeon, D.D. (chair); Quinn, J.F., Jr.; Bogan, A.E.; Coan, E.V.; Hochberg, F.G.; Lyons, W.G.; Mikkelsen, P.M.; Neves, R.J.; Roper, C.F.E.;

Rosenberg, G.; Roth, B.; Scheltema, A.; Thompson, F.G.; Vecchione, M.; Williams, J.D. 1998. Common and scientific names of aquatic

invertebrates from the United States and Canada: mollusks. 2nd ed. Amer. Fish. Soc. Spec. Publ. 26; 526 p.

c

Williams, A.B. (chair); Abele, L.G.; Felder, D.L.; Hobbs, H.H., Jr.; Manning, R.B.; McLaughlin, P.A.; Pérez Farfante, I. 1989. Common and

scientific names of aquatic invertebrates from the United States and Canada: decapod crustaceans. Amer. Fish. Soc. Spec. Publ. 17; 77 p.

d

Rice, D.W. 1998. Marine mammals of the world: systematics and distribution. Soc. Mar. Mammal. Spec. Publ. 4; 231 p.

e

Cooper, J.A.; Chapleau, F. 1998. Monophyly and interrelationships of the family Pleuronectidae (Pleuronectiformes), with a revised classification.

Fish. Bull. (U.S.) 96:686-726.

f

McEachran, J.D.; Dunn, K.A. 1998. Phylogenetic analysis of skates, a morphologically conservative clade of elasmobranchs (Chondrichthyes:

Rajidae). Copeia 1998(2):271-290.

g

ISO [International Organization for Standardization]. 1981. ISO standards handbook 3: statistical methods. 2nd ed. Geneva, Switzerland: ISO;

449 p.
Page iii

Contents

Background ...........................................................................................................................................................................1

Summary of Presentations and Discussions .........................................................................................................................1

Automated Acoustic Data Logging aboard Commercial Vessels ....................................................................................1

Environmental Influences on the Density Distribution of Atlantic Herring ....................................................................2

Fisheries-Independent Estimates from Acoustic Survey Data ........................................................................................3

In-situ Acoustic Measurements for Northwest Atlantic Herring ....................................................................................5

Ex-situ (laboratory) Experiments to Refine Acoustic Measurements ..............................................................................7

The Role of Fisheries Acoustics in Support of the Atlantic Herring Industry ................................................................9

Cooperative Fisheries Acoustic Research in the Gulf of Maine .................................................................................... 10

Atlantic Herring Assessment and Management in the Gulf of Maine .......................................................................... 10

Length-Stratified Target Strength Calculations for Biomass Estimates ......................................................................... 10

A Method for Beam-Width Calibration ......................................................................................................................... 11

Size Discrimination Using a Dual-Frequency System ................................................................................................... 11

Recent Multibeam Developments for Fisheries Acoustics ........................................................................................... 12

Spatial Statistical Approaches for Fisheries Acoustics ................................................................................................. 12

Spatial and Temporal Analysis of Fisheries Acoustic Data from Commercial Vessel Operations.................................. 12

Survey Design for Atlantic Herring Acoustic Surveys in the Newfoundland Region .................................................. 13

Closing Discussions ........................................................................................................................................................... 14

Data Management and Availability ............................................................................................................................... 14

Acoustic Estimates and Variances ................................................................................................................................ 15

Recommendations for Ongoing Research and the Next Workshop .................................................................................... 15

Appendices

Appendix A. Agenda of the Third Northwest Atlantic Herring Acoustic Workshop, University of Maine Darling

Marine Center, Walpole, Maine, March 13-14, 2001 .................................................................................... 16

Appendix B. List of Participants at the Third Northwest Atlantic Herring Acoustic Workshop, University of Maine

Darling Marine Center, Walpole, Maine, March 13-14, 2001 ....................................................................... 17

Figures

Figure 1. Spatial pattern of relative Atlantic herring abundance from fishery-dependent acoustic data collected by

the F/V Providian ...............................................................................................................................................2

Figure 2. Stratified random parallel transects with acoustic estimates for Atlantic herring................................................3

Figure 3. Systematic evenly-spaced parallel transects with acoustic estimates for Atlantic herring .................................4

Figure 4. Systematic zig-zag transects with acoustic estimates for Atlantic herring ..........................................................4

Figure 5. Atlantic herring observed by underwater static video in the Gulf of Maine during the 1997 in-situ target

strength experiment.............................................................................................................................................5

Figure 6. Individual target strength measurements for Atlantic herring at 38 kHz from the Gulf of Maine during August

1997 .....................................................................................................................................................................6

Figure 7. Individual target strength measurements for Atlantic herring at 120 kHz from the Gulf of Maine during August

1997 .....................................................................................................................................................................6

Figure 8. Lateral and dorsal radiographs of an alewife ......................................................................................................7

Figure 9. Graphic depiction of our laboratory experiments shows a live fish restrained in a mesh tube, which was

rotated at 10

 increments while insonified with a broadband signal .....................................................................8

Figure 10. Acoustic backscatter ambit of a 256-mm alewife at 38 kHz .................................................................................8

Figure 11. Schematic of the standard calibration procedure using a calibration sphere suspended by three

monofilament lines ............................................................................................................................................ 11

Figure 12. Longitudinal beam pattern of dual concentric transducer ................................................................................ 11
Page iv

Figure 13. Mean areal backscatter estimates, plus or minus two standard deviations, for Atlantic herring from three

survey designs and from a geostatistical estimator .......................................................................................... 13

Figure 14. Schematic diagram of multistart systematic survey design where transect placement in block A is randomly

chosen, but placement of transects in blocks B and C is determined by placement in block A ........................ 14

Acronyms

DFO = (Canada) Department of Fisheries and Oceans

GMA = Gulf of Maine Aquarium

HDPS = (Femto Electronics, Ltd.’s) Hydroacoustics Data Processing System

KRM = Kirchoff ray-mode model

MDMR = Maine Department of Marine Resources

NEFSC = (National Marine Fisheries Service’s) Northeast Fisheries Science Center

TRAC = (United States - Canada) Transboundary Resources Assessment Committee

TS = target strength

UM = University of Maine

VPA = virtual population analysis
Page 1

BACKGROUND

Early cooperative efforts by U.S. and Soviet scientists

to survey Atlantic herring (Clupea harengus) by using

hydroacoustics (“acoutics”) in the Northwest Atlantic began in the late 1960s. These research efforts were abandoned by the early 1970s due to the severe decline of Atlantic herring stocks on Georges Bank from overfishing, and to

the limitations of analog acoustic instrumentation. The

use of fisheries acoustics for research in U.S. waters of the

Northwest Atlantic did not resume for about two decades,

while scientists in government, academia, and industry

working in other regions continued to advance fisheries

acoustics. The development during the last decade of scientific quality echosounders with digital output and accurate calibration procedures has resulted in the international

acceptance of fisheries acoustics as a valuable tool for surveying and assessing pelagic fish populations.

A number of independent research efforts by Canadian

and U.S. scientists implemented fisheries acoustics to survey and estimate the biomass of Atlantic herring in various

regions of the Northwest Atlantic during the last decade.

Some of these scientists from the National Marine Fisheries

Service’s Northeast Fisheries Science Center (NEFSC), Canadian Department of Fisheries and Oceans (DFO), Maine

Department of Marine Resources (MDMR), and Gulf of

Maine Aquarium/University of Maine (GMA/UM) met in

Woods Hole, Massachusetts, in 1998 to discuss their acoustic research on Atlantic herring in the Gulf of Maine, Scotian

Shelf, and Georges Bank regions. That meeting was the

first in a series of Northwest Atlantic Herring Acoustic

Workshops. During the first workshop, scientists provided

an overview of their field operations and postprocessing

procedures. Fisheries acoustic research by the NEFSC included Simrad EK500, omnidirectional sonar, midwater trawling, and underwater video operations in the Georges Bank

and Gulf of Maine regions. Scientists from the DFO’s St.

Andrews Biological Station described their operations with

Femto echosounders, sidescan sonar, trawling, and seining

from commercial and research vessels on the Scotian Shelf

and Georges Bank. The DFO had also begun collaborative

efforts with the University of New Brunswick to develop

calibration and postprocessing procedures for the recently

developed Simrad SM2000 multibeam system. The MDMR

presented data based on the use of a Simrad EY500 aboard

charter vessels to survey Atlantic herring in coastal waters

and nearshore banks in the Gulf of Maine. The GMA/UM

initiated a project to implement automated acoustic data

loggers aboard commercial Atlantic herring vessels. An

overview was also provided on Simrad BI500, SonarData,

and Femto postprocessing software. The need to coordinate field operations, compare procedures and results, and

develop cooperative Atlantic herring acoustic research in

the Northwest Atlantic was recognized at the first workshop.

The second Northwest Atlantic Herring Acoustic Workshop occurred at UM’s Darling Marine Center in Walpole,

Maine, during January 18-19, 2000. Overviews were provided by NEFSC, DFO, MDMR, and GMA/UM scientists

of their 1998 and 1999 research, and these scientists compared preliminary biomass estimates. The results from an

intervessel comparison between the F/V Mary Ellen and

FR/V Delaware II were also presented. Scientists discussed

the importance of accurate calibrations. Approaches for

deriving Atlantic herring abundance and biomass estimates

by using acoustic data were discussed and recommended.

Representatives from the Atlantic herring fishing industry

attended the first day to provide suggestions for improving

survey operations. This workshop concluded with the planning and coordination of 2000 field operations.

The Third Northwest Atlantic Herring Acoustic Workshop was held at the Darling Marine Center during March

13-14, 2001. The workshop focused on specific topics identified during the second workshop that had the largest effect on the estimates and variances of the acoustic measurements. The participation was also expanded to include

additional Canadian scientists who had analytical expertise

in estimating the abundance of Atlantic herring by using

acoustic data from various regions in the Northwest Atlantic. The goals of this workshop were to evaluate ongoing

research in, identify research requirements of, and improve

cooperative operational and scientific efforts in, fisheries

acoustics to obtain more accurate, cost-effective, and timely

population estimates and variances for Atlantic herring assessment. This document summarizes the presentations

and discussions of the workshop.

SUMMARY OF PRESENTATIONS

AND DISCUSSIONS

Automated Acoustic Data Logging

aboard Commercial Vessels

Philip Yund

Darling Marine Center

University of Maine

Walpole, Maine, USA

Presentation

The Gulf of Maine Aquarium’s fisheries acoustic project

has collected acoustic data in both fishery-dependent (i.e.,

normal fishing operations) and fishery-independent (i.e.,

systematic transects) modes for 2 yr. Results from this

year’s (i.e., 2000) fishery-independent survey of

prespawning aggregations in the coastal waters of the Gulf

of Maine suggested a total spawning biomass of approximately 300,000 metric tons. A possible spawning aggrega-
Page 2

tion on Jeffreys Ledge in early November was not surveyed

due to scheduling conflicts.

In the fishery-dependent portion of the project, 2 yr of

data (i.e., 1999 and 2000) from the F/V Providian showed

consistently greater biomass on Georges Bank than from

coastal or nearshore bank waters (e.g., Jeffreys, Platts, and

Fippennies Ledge) in the Gulf of Maine (Figure 1). This

pattern was consistent with other acoustic results, and stock

assessments suggested that the Georges Bank component

of the stock is approximately an order-of-magnitude more

abundant than the nearshore Gulf of Maine stock.

Discussion

There is considerable U.S. interest for increasing the

use of commercial vessels to survey fish stocks, and of the

automated acoustic data logging system as a tool that can

be readily implemented. Good progress has been made

during the last 3 yr in the Gulf of Maine and Georges Bank

region with the collection and processing of acoustic data

from commercial Atlantic herring vessels. Biomass estimates from these data seem reasonable. The next step is to

implement the use of the acoustic estimates into the Atlantic herring management process. The Canadians have used

acoustic data from commercial vessels more extensively and

provide many lessons.

Environmental Influences on the Density

Distribution of Atlantic Herring

Philip Yund

Darling Marine Center

University of Maine

Walpole, Maine, USA

Presentation

We recently started to compare acoustic data to satellite and CTD (conductivity, temperature, and depth) data

on surface temperature and chlorophyll density to assess

possible oceanographic predictors of Atlantic herring distributions. Preliminary analyses (of two strata on Schoodic

Ridge) suggest that Atlantic herring appear to be distributed along frontal boundaries between water masses. Possible correlations with water depth and other variables will

be explored in future analyses.

Discussion

Atlantic herring are temperature sensitive, and their

density distributions can vary between years due to fluctuations in this variable. Environmental influences are an

important concern when determining the time and location

0

100000

200000

300000

400000

500000

Total Biomass (mt)

Coastal Nearshore Ledges Georges Bank

20 00

1999

Area

Figure 1. Spatial pattern of relative Atlantic herring abundance from fishery-dependent acoustic data collected by the F/V Providian.

Range estimate bars represent one standard deviation.
Page 3

of an acoustic survey. Questions were asked as to whether

Atlantic herring feed during spawning; the NEFSC has observed Atlantic herring feeding during the spawning period. A critical requirement of fisheries acoustic research in

support of management was recognized in that interannual

biomass indices should reflect trends in abundance rather

than environmental anomalies.

Fisheries-Independent Estimates

from Acoustic Survey Data

William J. Overholtz

Northeast Fisheries Science Center

National Marine Fisheries Service

Woods Hole, Massachusetts, USA

Presentation

Results from the autumn 2000 NEFSC Atlantic herring

hydroacoustic surveys were presented. Three different

survey designs -- systematic evenly-spaced parallel (Figure 2), stratified random parallel (Figure 3), and systematic

zigzag (Figure 4), were employed to survey the spawning

concentrations of Atlantic herring in the northern Georges

Bank region during September and October 2000. Results

suggest that Atlantic herring were abundant over the region, especially in the Cultivator Shoals area. The general

impression was that the entire spawning stock was probably covered during each of the three surveys. Survey

estimates indicate that the spawning biomass in the region

is probably large.

Two surveys, each utilizing a smaller set of transects

(i.e., seven), were conducted over a several day period in

early October. These surveys were designed to obtain information on the comparability of biomass estimates from

two replicates covering the same area. Biomass estimates

from these two surveys were similar, indicating that results

are reproducible, and that calibrations are reliable.

Future uses for the acoustics data were presented.

These uses included directly estimating abundance and

biomass, tuning age-structured models, and calibrating several types of biomass models, including surplus production

and delay-difference models.

Discussion

The NEFSC biomass estimates from acoustic surveys

are similar to the estimates from virtual population analysis,

and the estimates within and among acoustic survey designs are similar. The DFO applies the target strength (TS)-

length regression in a different manner than the NEFSC;

however, both approaches should produce the same result.

A review of these procedures and estimates will be conducted this year by the University of Miami’s Center for

Independent Experts. Ongoing research is focused on

evaluating survey design and estimation using classical

statistics and geostatistical procedures.

Figure 2. Stratified random parallel transects with acoustic estimates for Atlantic herring.
Page 4

Figure 3. Systematic evenly-spaced parallel transects with acoustic estimates for Atlantic herring.

Figure 4. Systematic zig-zag transects with acoustic estimates for Atlantic herring.
Page 5

In-situ Acoustic Measurements

for Northwest Atlantic Herring

William L. Michaels

Northeast Fisheries Science Center

National Marine Fisheries Service

Woods Hole, Massachusetts, USA

Presentation

Acoustic surveys have been conducted during the last 4

yr to estimate Atlantic herring biomass in the Gulf of Maine

and Georges Bank regions. During these cruises, individual

TS measurements for Atlantic herring have been collected to

determine an appropriate TS-length equation. This relationship is important because it directly affects the abundance and

biomass estimates when scaling the areal backscatter indices.

An in-situ TS experiment on Atlantic herring was conducted on Fippennies Ledge in the Gulf of Maine during

August 1997. Acoustic data were collected using a Simrad

EK500 echosounder operating three hull-mounted transducers (i.e., 12-kHz single beam, and 38- and 120-kHz split

beams). High-speed midwater rope trawl and Methot trawling operations were conducted to determine fish and

macrozooplankton composition, while underwater static

video provided direct observations of the acoustic targets

(Figure 5). The biological composition contributing to the

acoustic data was almost entirely Atlantic herring, euphausiids (Meganyctiphanes norvegica), and ctenophores. The

EK500 data were processed using the BI500 postprocessing

software. The compensated TSs, target depths, and offset

angles from the 38- and 120-kHz data were used to remove

potential false individual targets from slant range and angle

discrepancies. This multifrequency filter removed on average about 98-99% of the TS measurements to reduce the

multiple targets associated with tightly aggregated fish such

as Atlantic herring. The filter removed multiple targets,

resulting in lower TS distributions; however, the mean TS

for Atlantic herring in the Gulf of Maine region remained

relatively high in comparison to the literature (Figures 6 and

7). Further analyses are needed separate the high TS values that were most likely from larger fish (e.g., Atlantic cod

and haddock) and sharks that occurred in the study area.

Atlantic herring TS measurements during the day were

also significantly higher than during the night and twilight

periods. The EK500 omnidirectional sonar, midwater trawling, and underwater video sampling operations indicated

that Atlantic herring exhibited vertical migration patterns

from near bottom during the day into the water column at

night. Future efforts will be devoted to determining the TSlength relationship for Atlantic herring in the Northwest

Atlantic, and variability in TS distributions due to the species’ diel behavioral patterns, orientation, enlarged gonads,

or morphology.

Figure 5. Atlantic herring observed by underwater static video in the Gulf of Maine during the 1997 in-situ target strength experiment.
Page 6

Figure 6. Individual target strength measurements for Atlantic herring at 38 kHz from the Gulf of Maine during August 1997.

Figure 7. Individual target strength measurements for Atlantic herring at 120 kHz from the Gulf of Maine during August 1997.

-80 -70 -60 -50 -40 -30 -20

Target Strength (dB)

0.00

0.04

0.08

0.12

0.16

0.20

Relative Frequency

-80 -70 -60 -50 -40 -30 -20

0.00

0.04

0.08

0.12

0.16

0.20 Unfiltered 38kHz data (n=285,370) wide bars

Filtered 38kHz data (n=4,963) narrow bars

-80 -70 -60 -50 -40 -30 -20

Target Strength (dB)

0.00

0.04

0.08

0.12

0.16

0.20

Relative Frequency

-80 -70 -60 -50 -40 -30 -20

0.00

0.04

0.08

0.12

0.16

0.20 Unfiltered 120kHz data (n=455,605) wide bars

Filtered 120kHz data (n=4,963) narrow bars
Page 7

Discussion

These high TS measurements for Atlantic herring are

similar to observations from an earlier experiment conducted

by John Wheeler and George Rose. Workshop participants

presently use Foote’s equation (except for DFO in St. John’s,

Newfoundland), but all agree that a new TS-length equation should be developed for Atlantic herring in the Northwest Atlantic. The higher 38-kHz TS measurements observed by the NEFSC suggested that Foote’s intercept of -

71.9 dB might be increased to possibly -69 dB, resulting in a

decrease of the present biomass estimates by half, although

further analyses are needed. High TS values for Atlantic

herring from a pen experiment by the DFO in St. John’s,

Newfoundland, have resulted in the use of an intercept of -

66 dB for 120 kHz.

Ex-situ (laboratory) Experiments

to Refine Acoustic Measurements

J. Michael Jech

Northeast Fisheries Science Center

National Marine Fisheries Service

Woods Hole, Massachusetts, USA

Presentation

Fish are complicated scatterers of sound due to the

presence or absence of a swimbladder, the shape of the

body and/or swimbladder, their behavior, and life history

changes in anatomy. Anatomical attributes coupled with

organism behavior complicate predictions of fish length

from acoustic echoes, and influence the precision and accuracy of abundance or biomass estimates from acoustic

data. Combining theoretical acoustic models with in-situ

and laboratory measurements will help to explain variability

in acoustic backscatter, provide relationships between

length and acoustic measures, increase the precision and

accuracy of acoustic estimates, and improve target recognition and discrimination among acoustic targets. The Fisheries Acoustics Research Group at NEFSC has been working toward integrating acoustic models with in-situ and laboratory measurements to improve our biomass estimates of

pelagic fish stocks in the Gulf of Maine and Georges Bank

regions.

Procedures to obtain digital representations of a fish’s

body and swimbladder, predicted backscatter using a

Kirchhoff ray-mode model (KRM), and comparisons of predicted and laboratory measurements were presented at this

workshop. The KRM model uses the fish’s body and

swimbladder morphometry to predict echo amplitudes as a

function of fish length, acoustic frequency, and angle of

insonification. Radiographs in the dorsal and lateral planes

(Figure 8) are used to construct digital images of a fish’s

body and swimbladder. The KRM model approximates the

swimbladder and fish body shapes as finite cylinders and

then estimates acoustic backscatter as a function of acoustic frequency or fish aspect. The KRM model predicts a

nonmonotonic and nonlinear relationship between reduced

backscattering amplitude and fish length or acoustic frequency. In collaboration with scientists at the Woods Hole

Oceanographic Institution, measurements on live alewife

(Alosa pseudoharengus) were obtained in two planes (dorsal/ventral and lateral) of fish aspect angle (Figure 9). Comparisons of model predictions and laboratory measurements

suggest that the KRM model predictions are reliable and

robust over a wide range of fish aspect angles. We have

expanded the KRM model to predict backscattering amplitude for 3600

 of tilt and roll to produce a three-dimensional

Figure 8. Lateral and dorsal radiographs of an alewife. The swimbladder appears as a dark object relative to the skeletal structure. Note the

angle of the dorsal surface of the swimbladder relative to the sagittal axis (essentially the vertebral column) of the fish in the lateral

view.
Page 8

Figure 9. Graphic depiction of our laboratory experiments shows a live fish restrained in a mesh tube, which was rotated at 10

 increments while

insonified with a broadband (35-95 kHz) signal. Fish rotation was computer controlled and synchronized to the transmitted acoustic

pulses. Acoustic signals were digitally captured and analyzed for echo amplitudes and pulse compression techniques over a spectrum

of frequencies and fish lengths. These types of laboratory measurements provide a foundation for improving acoustic models to

quantify variability in acoustic biomass and fish length estimates.

Figure 10. Acoustic backscatter ambit of a 256-mm alewife at 38 kHz. Distance from the center of the axes represents backscatter amplitude.

Backscattering amplitude is color coded with highest amplitude as red and lowest amplitude as blue. Insonifying angle resolution is 20

in the tilt plane (head-tail) and 20 in the roll plane (dorsal-lateral-ventral). The ambit graphically depicts predicted echo amplitude

over all degrees of fish orientation. Echo amplitudes are greatly reduced at head-on and tail-on aspects. Maximum amplitudes are at

lateral incidences. Maximum dorsal amplitude occurs when the swimbladder is parallel to the incident wave front, which tilts the fish

approximately 120

 head down.
Page 9

backscattering surface (backscattering ambit, Figure 10).

The three-dimensional backscattering surface allows visualization and quantification of the effects of behavior on

echo amplitudes and prediction of acoustic backscatter measurements obtained by SONAR or multibeam technology.

Discussion

The laboratory measurements presented on alewife,

which has a similar morphology to that of the Atlantic herring, provide a detailed understanding of the species’ acoustic ambit which can help to explain the variability observed

with in-situ measurements. It was recommended that similar laboratory measurements on Atlantic herring are needed

to validate ongoing field investigations to derive a TS-length

relationship for Atlantic herring in the Northwest Atlantic.

It was also emphasized that the multifrequency measurements from the laboratory will also provide important parameters that allow intercalibration between existing Atlantic herring acoustic surveys that implement different frequencies for estimating abundance.

The Role of Fisheries Acoustics in Support

of the Atlantic Herring Industry

Jeff Kaelin

Stinson Seafood, Inc.

Winterport, Maine, USA

Presentation

Prior to joining Stinson Seafood, Inc., as Governmental

Affairs Coordinator in April 2000, Mr. Kaelin was employed

at the Executive Director of the Maine Sardine Council from

March 1986 until the council was dissolved on March 31,

2000. The Maine Sardine Council was an industry-funded

governmental entity of the State of Maine, established in

1951, that supported research on the Atlantic herring fishery and product quality control of benefit to the Maine

sardine industry and the State of Maine.

For many years, Maine’s sardine industry, which utilizes Atlantic herring for its products, has supported cooperative fisheries research projects to help estimate the abundance of Atlantic herring available for its operations. During the late 1970s, for example, the Maine Sardine Council

and the MDMR cooperated in the tagging of juvenile and

adult Atlantic herring along the Maine coast to help understand the migration of Atlantic herring from coastal Maine

spawning grounds. The information gathered from this work

serves as the basis for many of the assumptions of Atlantic

herring spawning stock behavior contained in the federal

Atlantic Herring Fishery Management Plan, approved by

the Secretary of Commerce in December 2000.

In recent years, the Maine sardine industry has supported investigations into the use of acoustic technology

to better estimate Atlantic herring abundance in the Gulf of

Maine and Georges Bank region, and to assist in establishing sustainable harvest levels for the resource. Industry

supported an acoustic Atlantic herring survey conducted

by Dr. Richard Nash and Dr. David Stevenson of the MDMR

around 1989. In 1995, the industry supported efforts by Dr.

Stevenson to attempt to use acoustics to survey Atlantic

herring abundance in the vicinity of Jeffreys Ledge, using a

combination of state and federal funds. In 1997, working in

cooperation with the GMA and the NEFSC, the industry

helped to identify the need to establish a world class acoustic survey capability at the NEFSC, and supported the use

of acoustic technology on commercial vessels so that surveys could be carried out where NEFSC vessels cannot

operate due to shallow water depths.

During Fiscal Years 1998, 1999, and 2000, the Maine

sardine industry, with the assistance of the Maine Congressional Delegation, was successful in having $800,000

added to the NEFSC budget to establish its acoustic survey program. A portion of these funds has been utilized to

continue the development of the commercial-vessel survey

component. For Fiscal Year 2003 (i.e., October 1, 2002,

through September 30, 2003), Stinson Seafood and the GMA

are again asking Congress to increase the NEFSC acoustic

survey budget, from $200,000 to $500,000, to ensure the

continued development of the region’s ability to survey

Atlantic herring spawning stock abundance at a time when

acoustic surveys have begun to be used to determine the

abundance of other pelagic species such as Atlantic mackerel and squids.

Discussion

Good progress has been made with implementing fisheries acoustics for estimating Atlantic herring populations

in the region. The acoustic estimates are needed to help

managers make important Atlantic herring management decisions. Fishers have reported large aggregations of Atlantic herring on northern Georges Bank during the fall (similar

to the NEFSC results), and the acoustic estimates will help

in assessing the size of the offshore resource.
Page 10

Cooperative Fisheries Acoustic Research

in the Gulf of Maine

Donald Perkins

Gulf of Maine Aquarium Development Corporation

Portland, Maine, USA

Presentation

The fisheries acoustic research on Atlantic herring in

the Gulf of Maine region during recent years provides an

excellent example of cooperative efforts between government agencies and industry. The Gulf of Maine Aquarium

Development Corporation’s web site (http://

www.FishResearch.org/) was introduced as a tool for increasing cooperative opportunities between scientists and

commercial fishers. There is considerable interest from industry and funding agencies to foster cooperative research

such as the ongoing Atlantic herring acoustic research.

Discussion

Funding and collaborative research opportunities were

discussed.

Atlantic Herring Assessment and Management

in the Gulf of Maine

David A. Libby

Maine Department of Marine Resources

West Boothbay, Maine, USA

Presentation

Atlantic herring assessment and management in the Gulf

of Maine were summarized. Atlantic herring catches were

presented for management areas by month for 1998-2000.

Graphical presentations of catches were compiled by 10-

min square on a bimonthly basis from August through December 1998-2000 to correspond with inshore and offshore

acoustic surveys. Preparations are being made for a collaborative United States - Canada Transboundary Resources

Assessment Committee (TRAC) assessment meeting on

Atlantic herring in 2002.

Discussion

Commercial catch data which corresponds in time and

space with Atlantic herring acoustic survey data can improve the partitioning of acoustic data by species. There

was discussion regarding the spawning tolerance used to

manage fishing on spawning components in the Gulf of

Maine. Alternative management strategies used in other

areas were also discussed. There was also discussion of

the plans to incorporate and review the acoustic estimates

of Atlantic herring biomass at the TRAC meeting scheduled for 2003.

Length-Stratified Target Strength Calculations

for Biomass Estimates

Claude Leblanc

Gulf Fisheries Center

Department of Fisheries and Oceans

Moncton, New Brunswick, Canada

Presentation

The Southern Gulf of St. Lawrence annual acoustic survey is held at the end of September on Atlantic herring

feeding aggregations in inshore areas between 20- and 60-

m depths. All major acoustic backscattering detected during survey operations was verified using a midwater trawl

for species compositions and length-frequency distributions of Atlantic herring schools. To apply the length-frequency distribution in calculating a mean TS, the following

procedure is used. From the detailed biological samples

collected per trawl sets, a length-weight regression is calculated to obtain slope and intercept values for the relation:

W = aLb

. We then use Foote’s formula to calculate a TS for

every length in the frequency distribution, with the second

part of the equation giving us a TS value per kilogram:

TS = (20 · log10Lcm - 71.9) - (10 · log10 · Wkg)

We then linearize the TS values per length by using:

TSlinearized = 10 (TS/10)

This linearized value of the TS is then multiplied by the

number of fish measured for each length in the length-frequency distribution. We next sum the products of this

multiplication for all lengths, and divide the sum by the

total number of fish in the length-frequency sample. This

value is a weighted-mean, linearized TS for the entire lengthfrequency sample. Finally, we take the antilog value of this

weighted-mean, linearized TS to give us a weighted-mean

TS in decibels per kilogram.

Discussion

The calculations presented above are the procedures used

by the GMA/UM and DFO participants in which an average

value of -35.5 dB/kg was used. The NEFSC scientists presently derive the biomass estimates in a slightly different manner, which should produce the same results. The NEFSC approach is to obtain a mean length from a series of transects

which is converted to TS using Foote’s equation. The individual TS is used to derive the cross-sectional backscatter

coefficient of an individual Atlantic herring which is used to

divide the mean areal backscatter (Sa) estimates to obtain the

number of fish. This estimate is converted to biomass by

multiplying it by the mean weight per fish derived from the

length-to-weight conversion from the survey. The NEFSC

scientists will check both approaches to ensure there are no

discrepancies in their biomass estimates.
Page 11

A Method for Beam-Width Calibration

Allen Clay

Femto Electronics, Ltd.

Sackville, Nova Scotia , Canada

Presentation

Allen Clay from Femto Electronics spoke on recent developments in the firm’s Hydroacoustics Data Processing

System (HDPS). The beam-angle calibration initiative within

the HDPS is primarily intended to improve the confidence

in a transducer manufacturer’s beam-angle specification,

an important parameter in the acoustic integration process.

It has also been used to determine the health of all transducer elements, as well as for reviewing the position and

amplitude of side lobes. On one occasion, it was instrumental in determining which of two possible transducers

was installed on an Atlantic herring seiner. The developed

software predicts the beam pattern based on slight ball

movements as a result of changes in the line lengths of

each of the three suspension lines (Figure 11). The software also accounts for the stretching and shrinkage in the

monofilament line as the ball is moved. Upon completion of

the procedure, the software predicts the error associated

with the estimate of biomass should the manufacturer’s

specification be chosen over the actual values.

Discussion

It was recognized that most transducer calibrations conducted in the field rely on the manufacturer’s beam-angle

specification. Although there are calibration programs (i.e.,

Simrad Lobe program) that derive beam offset parameters,

these values are not truly independent from the

manufacturer’s specifications.

Size Discrimination Using a Dual-Frequency System

Allen Clay

Femto Electronics, Ltd.

Sackville, Nova Scotia , Canada

Presentation

The new Femto DE9320 Dual Frequency Digital

Echosounder with the 40/120/9.2 Dual Concentric Transducer

was presented as a new initiative for addressing areas of interest in the Atlantic herring fishing community. Femto plans to

exploit this technology to assist in such concerns as mean

target size within a school, mean maturity stage, and Atlantic

herring behavioral separation. In the long term, Femto also

hopes to provide a tool for bottom typing studies. Preliminary

study indicates that the TS of an Atlantic herring of length L

obtained by using a frequency F may follow a relationship

described by:

TS = 10 · Log [B · L2

 · Trig (C · L · F)]

where B and C are constants and Trig is a trigonometric function to be determined. In reviewing the modeling studies done

by Mike Jech of the NEFSC and presented at the workshop,

there are indications that this trigonometric function may exhibit multiple maxima over the commercial size range of Atlantic herring. Although it is not anticipated that this work will

quickly lead to a quantitative measure of mean target size since

many other factors will influence variability in the signal, it is

felt that we will be moving closer to a solution, and that in the

meantime, the technology may help fishers in their efforts to

target fish of a size needed for a particular market.

Discussion

The advantages with two identical 3-dB beam patterns of

different frequencies from a single transducer were discussed

(Figure 12). This development will provide improved target

classification, and does not have the disadvantage of the varying beam patterns associated with broadband systems.

Figure 11. Schematic of the standard calibration procedure using a

calibration sphere suspended by three monofilament lines. Figure 12. Longitudinal beam pattern of dual concentric transducer.
Page 12

Recent Multibeam Developments

for Fisheries Acoustics

Gary Melvin (presented by Michael Jech)

St. Andrews Biological Station

Department of Fisheries and Oceans

St. Andrews, New Brunswick, Canada

Presentation

An overview on the history and recent developments

in the application of multibeam sonar technology to fisheries research was presented. Collaborative efforts between

scientists from the University of New Brunswick, DFO’s St.

Andrews Biological Station, and the University of New

Hampshire have made good progress in the development

of calibration procedures and postprocessing software for

the Simrad SM2000 Multibeam System. The SM2000 is presently the only multibeam system available that collects backscatter data from the water column for fisheries acoustic

research. Development of the calibration procedures and

postprocessing software is a critical prerequisite before

SM2000 survey operations can be routinely implemented.

Extensive progress was made over the past year on

calibrating the sonar in order that signal returns from the

system can be quantified. The first calibration coefficients

obtained from an experiment in February 2001 are presently

being incorporated into the display software for computation of volume backscatter. Advances have also been made

in the 3D visualization of multibeam data. At present, it is

possible to display up to 60 pings on the screen in real time.

This provides 3D form to objects as the vessel passes over

the bottom. A function is available within the software to

count echoes when individual targets are observed in the

data. The first attempt to implement multibeam sonar on

survey operations for estimating Atlantic herring biomass

is scheduled for 2001.

Discussion

Implementation of the SM2000 Multibeam System for

fisheries acoustic surveys has been proposed in the Northwest Atlantic by a number of agencies and funding programs. SM2000 installation has also been proposed on

new NOAA research vessels. Ongoing research and development with SM2000 calibration and postprocessing software are critical requirements before the SM2000 can be

routinely used during survey operations.

Spatial Statistical Approaches

for Fisheries Acoustics

Patrick J. Sullivan

Department of Natural Resources

Cornell University

Ithaca, New York, USA

Presentation

Mean biomass estimates and variances were compared

from three survey designs (incorporating stratified random

parallel, systematic evenly-spaced parallel, and systematic

zig-zag transects) on northern Georges Bank during fall 2000

(Figure 13). There appeared to be insignificant differences

between the estimates, suggesting that biomass estimates

from fisheries acoustic operations were robust. A

geostatistical estimator (e.g., kriging) provided a similar mean

with reduced variance (Figure 13).

Spatial and Temporal Analysis

of Fisheries Acoustic Data

from Commercial Vessel Operations

Ross Claytor

Bedford Institute of Oceanography

Dartmouth, Nova Scotia, Canada

Presentation

A method for measuring the spatial and temporal distribution of fish school densities and their exploitation rates

using fishery-collected acoustic data and Voronoi - natural

neighborhood analysis was described. An Atlantic herring

purse seiner fishing on nonspawning feeding aggregations,

and an Atlantic herring gillnetter fishing on smaller, highly

dense spawning aggregations, in the southern Gulf of St.

Lawrence, Canada, collected acoustic data for this study

during their regular fishing activity. The declining-catchper-unit-of-effort estimator, which was associated with the

gillnet fishing and which was used to assess this stock,

reached asymptotic values at lower-than-expected levels,

and was not useful for tracking daily trends in school density.

Gillnet and purse seine catch per distance searched

during fishing operations was linearly related to school

density, and likely is a suitable abundance index for stock
Page 13

assessment estimates. An individual boat which collected

data in this manner was found to represent trends in the

entire fleet. There was a threshold density below which

exploitation rates remained low. This threshold provides

managers with a method for identifying high exploitation

rates and preventing overfishing.

A simulation model calibrated with data from the Pictou

1997 inshore gillnet fishery compared the properties of abundance indices derived from fishery acoustic data to those

derived from survey indices. The indices were examined

over five fish distribution types, ranging from a single spike

to a uniform flat distribution, four conditions of fishing and

fish movement, and 16 stock sizes for each of these distribution and conditions. These acoustic data are suitable for

deriving abundance indices provided the searching covers

the entire population.

Fishery acoustic abundance indices provide a basis for

adopting a decision-rule management paradigm, and for allowing the metapopulation structure of Atlantic herring to

become the basic management unit for this species. These

results represent an important alternative to the current F0.1

management paradigm for Atlantic herring populations, and

offer an opportunity to develop a more transparent and

responsive management system for the long-term viability

of Atlantic herring fisheries.

Discussion

Discussions focused on the advantages of estimating

exploitation rate from acoustic data collected from commercial vessels. Catch per search distance is considered more

sensitive to changes in biomass than catch per net, and

less sensitive to varying catch efficiencies among vessels.

Survey Design for Atlantic Herring Acoustic

Surveys in the Newfoundland Region

John P. Wheeler

Northwest Atlantic Fisheries Center

Department of Fisheries and Oceans

St. John’s, Newfoundland, Canada

Presentation

Acoustic surveys have been conducted on an annual

basis since the early 1980s as part of the research program

to assess Atlantic herring stocks in the Newfoundland Region. Currently, four coastal stocks are surveyed acoustically on an alternate year basis to estimate stock biomass.

Surveys are conducted either during the late fall or overwintering period, depending upon stock area.

Figure 13. Mean areal backscattering estimates, plus or minus two standard deviations (95% confidence interval), for Atlantic herring from three

survey designs (i.e., stratified random parallel, systematic evenly-spaced parallel, and systematic zig-zag transects) and from a

geostatistical estimator (i.e., kriging of zig-zag transects).
Page 14

In all surveys, the survey area is defined as the area

from the coastline to the 120-m depth contour. The 120-m

depth contour was selected as the outer boundary as it has

been shown that most Atlantic herring are distributed within

this depth range during the survey period. The survey

areas are divided into strata based upon geographical features and Atlantic herring distribution patterns. Acoustic

sampling intensity (i.e., total transect length) is allocated to

these strata on a proportional basis based upon Atlantic

herring distributional patterns observed in the commercial

fishery and previous acoustic surveys.

The survey design within strata has evolved during the

time series. Originally, zigzag transects were used; subsequently, random parallel and systematic transects were used.

Currently, a multistart systematic design is employed (Figure 14). Each stratum is subdivided into blocks with an

equal number of parallel transects per block. Placement of

transects is randomly selected in the first block of a stratum, but is defined by this placement in the remaining blocks.

As transects can be of varying lengths within blocks,

weighted mean densities are calculated for each stratum

and extrapolated to the stratum area to estimate fish biomass. Strata estimates are summed to calculate a total biomass estimate for the survey area.

The multistart systematic design, currently employed,

is deemed to be advantageous as it allows for the distribution of acoustic sampling intensity over the survey area in

a semisystematic manner, while retaining the ability to calculate a survey-based variance estimate.

Discussion

There was discussion regarding the survey design.

Strata were oriented perpendicular to the coastal baseline.

This design strategy has the advantage of randomness and

even spacing of the transects. This design was decided

upon after a working group reviewed the advantages and

disadvantages of various designs used in fisheries acoustic surveys. Further insight was also provided on how cruise

sampling was allocated among stratum based on densities

from previous cruises. The remaining discussion involved

concern about whether Foote’s equation was appropriate

for Atlantic herring in the Northwest Atlantic. The DFO in

Newfoundland used a different TS-length equation with an

intercept at –66 dB (for 120 kHz) derived from an earlier TS

experiment, and this seems to support the high TS measurements observed by the NEFSC.

CLOSING DISCUSSIONS

Data Management and Availability

Closing discussions began with a summary of NEFSC

data management and availability. Efforts are underway to

archive these data in the NEFSC Oracle database which can

be readily accessed by assessment scientists. The NEFSC

Atlantic herring acoustic information (i.e.,cruise reports,

acoustic estimates, and station/catch/biological data from

Figure 14. Schematic diagram of multistart systematic survey design where transect placement in block A is randomly chosen, but placement of

transects in blocks B and C is determined by placement in block A.
Page 15

midwater trawl operation) from the 1998-2000 fall surveys

were distributed to workshop participates. There was discussion about the advantage of minimal thresholding. Relational data management using Oracle is agreed to be a

good approach which can be readily incorporated into new

tools (e.g., trawl/acoustical visualization software).

Some participants from DFO and MDMR/GMA manage their acoustic data using Femto’s HDPS data structure.

The HDPS archives raw data. The NEFSC does not archive

raw data. The NEFSC data are logged to the BI500

postprocessor which derives estimates with 2-sec, 0.5-m

depth bins, and 0.5-nmi resolution. Data to this resolution

are equivalent to about 2 gigabytes per 12-day cruise (i.e.,

about 4,000 nmi).

In regard to the TS data, it was recommended that the

raw data be collected from the EK500 serial port rather than

using only binned measurements from the BI500. It was

agreed that raw data will be collected on future NEFSC

acoustic surveys on selected transects where single-species TS data can be obtained.

The MDMR provided commercial Atlantic herring catch

data that can be overlaid with the 1998-2000 Atlantic herring acoustic surveys. Concern was addressed regarding

accessibility and confidentiality of commercial catch data.

Implementation of VMS vessel tracking in the Gulf of Maine

this year will provide more accurate information of commercial operations in real time. Canadian scientists have found

VMS tracking not only useful for research and management, but the commercial fishers also have readily accepted

vessel tracking as a valuable tool. The commercial vessels

knew where other vessels were fishing anyway, and they

would prefer to work cooperatively.

Acoustic Estimates and Variances

The discussion began with two questions: what level

of accuracy is needed for estimates and variances from Atlantic herring acoustic surveys, and how will the estimates

be used? Most participants are presently using the estimates to tune virtual population analysis (VPA) estimates,

while Gary Melvin is presently the only participant who is

using acoustic estimates as a direct biomass estimate. Gary

Melvin is dealing with relatively low F values, while VPA

seems to work better with high F values. The goal of the

NEFSC is to use the acoustic estimates as both an indirect

(i.e., tuning VPA) and direct (i.e., biomass estimate to anchor population models) approach for assessment of Atlantic herring.

Point estimates with confidence intervals are required.

Low variance of about 25% is desirable. Geostatistics and

bootstrapping appear to be useful approaches for approximating variance. Discrepancies between observed TS measurements and Foote’s equation for the Northwest Atlantic

herring are a major concern that can significantly affect the

biomass estimates; therefore, TS needs further investigation. Design and timing of the survey are another critical

element. For example, annual acoustic surveys for Atlantic

herring in the Gulf of St. Lawrence began in 1985; however,

a meaningful time series did not begin until 1994. This is

because distributional shifts of Atlantic herring made for

difficult timing and placement of the surveys. Timing and

placement of the Atlantic herring acoustic survey on northern Georges Bank do not appear to be a problem given the

high biomass, however surveying the nearshore banks and

coastal waters of the Gulf of Maine is a problem which needs

to be addressed to attain the goal of annual biomass estimates.

RECOMMENDATIONS FOR ONGOING

RESEARCH AND THE NEXT

WORKSHOP

Agenda suggestions for the next Northwest Atlantic

Herring Acoustic Workshop include: 1) sources of error in

biomass estimates, 2) TS-length relationship for Atlantic

herring, 3) geostatistics, 4) survey design, 5) shallow-water

acoustics, and 6) new acoustic technologies. It was recommended that the next workshop be held at the St. Andrews

Biological Station in New Brunswick during spring or early

summer 2002.
Page 16

APPENDIX A

Agenda of the Third Northwest Atlantic Herring Acoustic Workshop,

University of Maine Darling Marine Center, Walpole, Maine, March 13-14, 2001

March 13

09:00 General Scientific Goals of the Workshop

09:05 Automated Acoustic Data Logging aboard Commercial Vessels (P. Yund)

09:35 Environmental Influences on the Density Distribution of Atlantic Herring (P. Yund)

09:50 Fisheries-Independent Estimates from Acoustic Survey Data (W. Overholtz)

10:15 Break

10:20 Verifying in-situ Acoustic Measurements for Atlantic Herring (W. Michaels)

11:05 Ex-situ (laboratory) Experiments to Refine Acoustic Measurements (M. Jech)

11:50 The Role of Fisheries Acoustics in Support of the Atlantic Herring Industry (J. Kaelin)

12:10 Lunch

13:00 Cooperative Fisheries Acoustic Research in the Gulf of Maine (D. Perkins)

13:20 Atlantic Herring Assessment and Management in the Gulf of Maine (D. Libby)

13:30 Length Stratified Acoustic Estimates (C. Leblanc)

14:45 Break

15:00 A Method for Beam-Width Calibration (A. Clay)

15:50 Size Discrimination Using a Dual Frequency System (A. Clay)

16:20 Recent Multibeam Developments for Fisheries Acoustics (M. Jech for G. Melvin)

March 14

08:00 Spatial Statistical Approaches for Fisheries Acoustics (P. Sullivan)

09:15 Spatial and Temporal Analysis of Fisheries Acoustic Data from Commercial Vessel Operations (R. Claytor)

10:00 Survey Design for Atlantic Herring Acoustic Surveys in the Newfoundland Region (J. Wheeler)

11:00 Break

11:10 Discussion on Acoustic Data Management

11:25 Closing Discussions of Workshop, Ongoing Research, and Next Year’s Agenda

12:00 Lunch

13:00 Closing Discussions on Estimates and Variance from Atlantic Herring Acoustic Surveys
Page 17

APPENDIX B

List of Participants for the Third Northwest Atlantic Herring Acoustic Workshop,

University of Maine Darling Marine Center, Walpole, Maine, March 13-14, 2001

Peter Chase

Northeast Fisheries Science Center

National Marine Fisheries Service

166 Water Street

Woods Hole, MA 02543

Voice: 508-495-2348

Fax: 508-495-2258

Peter.Chase@noaa.gov

Matt Cieri

Maine Department of Marine Resources

West Boothbay Harbor, ME 04575

Voice: 207-633-9500

Matthew.Cieri@state.me.us

Allen Clay

Femto Electronics, Ltd.

P.O. Box 690

Sackville, Nova Scotia B4C-3J1

Voice: 902-865-8565

Fax: 902-865-8558

aclay@sprint.ca

Ross Claytor

Bedford Institute of Oceanography

P.O. Box 1006

Dartmouth, Nova Scotia B2Y-4A2

Voice: 902-426-4721

Fax: 902-426-1862

ClaytorR@mar.dfo-mpo.gc.ca

Kara Dwyer

Northeast Fisheries Science Center

National Marine Fisheries Service

166 Water Street

Woods Hole, MA 02543

Voice: 508-495-2274

Fax: 508-495-2258

Kara.Dwyer@noaa.gov

J. Michael Jech

Northeast Fisheries Science Center

National Marine Fisheries Service

166 Water Street

Woods Hole, MA 02543

Voice: 508-495-2353

Fax: 508-495-2258

Michael.Jech@noaa.gov

Jeff Kaelin

Stinson Seafood, Inc.

P.O. Box 440

Winterport, ME 04496-0440

Voice: 207-223-9013

Fax: 207-223-9900

msardine@mint.net

Kohl Kanwit

Maine Department of Marine Resources

West Boothbay Harbor, ME 04575

Voice: 207-633-9535

Kohl.Kanwit@state.me.us

Andone Lavery

Woods Hole Oceanographic Institution

Woods Hole, MA 02543

Voice: 508-548-1400

alavery@whoi.edu

Claude Leblanc

Gulf Fisheries Center

Department of Fisheries and Oceans

P.O. Box 5030

Moncton, New Brunswick E1C-9B6

Voice: 506-851-3870

Fax: 506-851-2620

LeblancCH@dfo-mpo.gc.ca

David Libby

Maine Department of Marine Resources

West Boothbay Harbor, ME 04575

Voice: 207-633-9532

David.A.Libby@state.me.us

Gary Melvin

St. Andrews Biological Station

Department of Fisheries and Oceans

St. Andrews, New Brunswick E5B2L9

Voice: 506-529-8854

Fax: 506-529-5862

MelvinG@mar.dfo-mpo.gc.ca
Page 18

William Michaels

Northeast Fisheries Science Center

National Marine Fisheries Service

166 Water Street

Woods Hole, MA 02543

Voice: 508-495-2259

Fax: 508-495-2258

William.Michaels@noaa.gov

William Overholtz

Northeast Fisheries Science Center

National Marine Fisheries Service

166 Water Street

Woods Hole, MA 02543

Voice: 508-495-2256

Fax: 508-495-2393

William.Overholtz@noaa.gov

Donald Perkins

Gulf of Maine Aquarium Development Corporation

P.O. Box 7549

Portland, ME 04112

Voice: 207-871-7804

Fax: 207-772-6855

donnyp@maine.rr.com

Shale Rosen

Darling Marine Center

University of Maine

193 Clark’s Cove Road

Walpole, ME 04573

207-563-3146 x 331

ShaleRosen@gma.org

Patrick J. Sullivan

Department of Natural Resources

214 Fernow Hall

Cornell University

Ithaca, NY 14853-3001

Voice: 607-255-8213

Fax: 607-255-8837

Pjs31@cornell.edu

Ed Tooley

Little Bay Lobster Co.

415 Turnpike Drive

Camden, ME 04843

Voice: 207-763-4470

Fax: 207-763-4176

herring@midcoast.com

John P. Wheeler

Northwest Atlantic Fisheries Center

Department of Fisheries and Oceans

P.O. Box 5667

St. John’s, Newfoundland A1C-5X1

Voice: 709-772-2005

Fax: 709-772-4188

wheeler@athena.nwafc.nf.ca

Philip Yund

Biological Oceanography Program

Division of Ocean Sciences

National Science Foundation

4201 Wilson Blvd.

Arlington, VA 22230

Voice: 703-292-8582

Fax: 703-292-9085

pyund@nsf.gov
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(i.e., Fishery Bulletin, NOAA Technical Report NMFS, or Marine Fisheries Review).

Identical, or fundamentally identical, manuscripts should

not be concurrently submitted to this and any other publication

series. Manuscripts which have been rejected by any primary

series strictly because of geographic or temporal limitations may

be submitted to this series.

Manuscripts by Northeast Fisheries Science Center

(NEFSC) authors will be published in this series upon approval

by the NEFSC's Deputy Science & Research Director. Manuscripts by non-NEFSC authors may be published in this series if:

1) the manuscript serves the NEFSC’s mission; 2) the manuscript meets the Deputy Science & Research Director’s approval; and 3) the author arranges for the printing and binding

funds to be transferred to the NEFSC’s Research Communications Unit account from another federal account. For all manuscripts submitted by non-NEFSC authors and published in this

series, the NEFSC will disavow all responsibility for the manuscripts’ contents; authors must accept such responsibility.

The ethics of scientific research and scientific publishing

are a serious matter. All manuscripts submitted to this series are

expected to adhere -- at a minimum -- to the ethical guidelines

contained in Chapter 1 (“Ethical Conduct in Authorship and

Publication”) of the CBE Style Manual, fifth edition (Chicago,

IL: Council of Biology Editors). Copies of the manual are

available at virtually all scientific libraries.

Manuscript Preparation

Organization: Manuscripts must have an abstract, table of

contents, and -- if applicable -- lists of tables, figures, and

acronyms. As much as possible, use traditional scientific

manuscript organization for sections: “Introduction,” “Study

Area,” “Methods & Materials,” “Results,” “Discussion” and/or

“Conclusions,” “Acknowledgments,” and “References Cited.”

Style: All NEFSC publication and report series are obligated to conform to the style contained in the most recent edition

of the United States Government Printing Office Style Manual.

That style manual is silent on many aspects of scientific manuscripts. NEFSC publication and report series rely more on the

CBE Style Manual, fifth edition.

For in-text citations, use the name-date system. A special

effort should be made to ensure that the list of cited works

contains all necessary bibliographic information. For abbreviating serial titles in such lists, use the most recent edition of the

BIOSIS Serial Sources (Philadelphia, PA: Biosciences Information Service). Personal communications must include date of

contact and full name and mailing address of source.

For spelling of scientific and common names of fishes,

mollusks, and decapod crustaceans from the United States and

Canada, use Special Publications No. 20 (fishes), 26 (mollusks),

and 17 (decapod crustaceans) of the American Fisheries Society

(Bethesda, MD). For spelling of scientific and common names

of marine mammals, use Special Publication No. 4 of the

Society for Marine Mammalogy (Lawrence, KS). For spelling in

general, use the most recent edition of Webster’s Third New

International Dictionary of the English Language Unabridged

(Springfield, MA: G.&C. Merriam).

Typing text, tables, and figure captions: Text, tables,

and figure captions must be converted to the NOAA-wide

standard of WordPerfect. In general, keep text simple (e.g.,

don’t switch fonts and type sizes, don’t use hard returns within

paragraphs, don’t indent except to begin paragraphs). Also,

don't use the WordPerfect automatic footnoting function; all

notes should be indicated in the text by simple numerical

superscripts, and listed together in an "Endnotes" section prior

to the "References Cited" section. Especially, don’t use the

WordPerfect graphics function for embedding tables and figures

in text.

Tables may be prepared either with WordPerfect text or

with the WordPerfect table formatting function. If text is used,

then data should be assigned to columns by using all tabs or all

spaces, but not a combination of the two.

Each figure should be supplied both on paper and on disk,

unless there is no digital file of a given figure. Except under

extraordinary circumstances, color will not be used in illustrations.

Manuscript Submission

Authors must submit one paper copy of the double-spaced

manuscript, one disk copy, and original figures (if applicable).

NEFSC authors must include a completely signed-off “NEFSC

Manuscript/Abstract/Webpage Review Form.” Non-NEFSC

authors who are not federal employees will be required to sign

a “Release of Copyright” form.

Send all materials and address all correspondence to:

Jon A. Gibson (Biological Sciences Editor)

NMFS Northeast Fisheries Science Center

166 Water Street

Woods Hole, MA 02543-1026 USA.

NORTHEAST FISHERIES SCIENCE CENTER

Dr. Michael P. Sissenwine, Science & Research Director

Capt. John T. Moakley, Operations, Management & Information Services Chief

Teri L. Frady, Research Communications Chief
Research Communications Unit

Northeast Fisheries Science Center

National Marine Fisheries Service, NOAA

166 Water St.

Woods Hole, MA 02543-1026

NOAA Technical Memorandum NMFS-NE -- This series is issued irregularly. The series typically includes: data reports of longterm or large-area studies; synthesis reports for major resources or habitats; analytical reports of environmental conditions or phenomena;

annual reports of assessment or monitoring programs; manuals describing unprecedented field and lab techniques; literature surveys of

major resource or habitat topics; proceedings and collected papers of scientific meetings; and indexed and/or annotated bibliographies.

All issues receive internal scientific review and most issues receive technical and copy editing.

Fishermen's Report -- This information report is a quick-turnaround report on the distribution and relative abundance of commercial

fisheries resources as derived from each of the NEFSC's periodic research vessel surveys of the Northeast's continental shelf. There is

no scientific review, nor any technical or copy editing, of this report.

Northeast Fisheries Science Center Reference Document -- This series is issued irregularly. The series typically includes: data reports

on field and lab observations or experiments; progress reports on continuing experiments, monitoring, and assessments; manuals

describing routine surveying and sampling programs; background papers for, and summary reports of, scientific meetings; and simple

bibliographies. Issues receive internal scientific review, but no technical or copy editing.

The mission of NOAA's National Marine Fisheries Service (NMFS) is "stewardship of living marine resources for the benefit of the

nation through their science-based conservation and management and promotion of the health of their environment." As the research

arm of the NMFS's Northeast Region, the Northeast Fisheries Science Center (NEFSC) supports the NMFS mission by "planning,

developing, and managing multidisciplinary programs of basic and applied research to: 1) better understand the living marine

resources (including marine mammals) of the Northwest Atlantic, and the environmental quality essential for their existence and

continued productivity; and 2) describe and provide to management, industry, and the public, options for the utilization and

conservation of living marine resources and maintenance of environmental quality which are consistent with national and regional

goals and needs, and with international commitments." Results of NEFSC research are largely reported in primary scientific media

(e.g., anonymously-peer-reviewed scientific journals). However, to assist itself in providing data, information, and advice to its

constituents, the NEFSC occasionally releases its results in its own media. Those media are in four categories:

Publications and Reports

of the

Northeast Fisheries Science Center

OBTAINING A COPY: To obtain a copy of a NOAA Technical Memorandum NMFS-NE or a Northeast Fisheries Science

Center Reference Document, or to subscribe to the Fishermen's Report or the The Shark Tagger, either contact the NEFSC

Editorial Office (166 Water St., Woods Hole, MA 02543-1026; 508-495-2228) or consult the NEFSC webpage on "Reports

and Publications" (http://www.nefsc.noaa.gov/nefsc/publications/).

ANY USE OF TRADE OR BRAND NAMES IN ANY NEFSC PUBLICATION OR REPORT DOES NOT IMPLY

ENDORSEMENT.

MEDIA

 MAIL

The Shark Tagger -- This newsletter is an annual summary of tagging and recapture data on large pelagic sharks as derived from the

NMFS's Cooperative Shark Tagging Program; it also presents information on the biology (movement, growth, reproduction, etc.) of these

sharks as subsequently derived from the tagging and recapture data. There is internal scientific review, but no technical or copy editing,

of this newsletter.