Fish Population and Behavior Fish Population and Behavior Revealed by Instantaneous Revealed by Instantaneous

Continental-Shelf-Scale ImagingContinental-Shelf-Scale Imaging

Nicholas C. Makris, Massachusetts Institute of Technology

Purnima Ratilal, Northeastern University

Deanelle Symonds, Massachusetts Institute of Technology

Srinivasan Jagannathan, Massachusetts Institute of Technology

Sunwoong Lee, Massachusetts Institute of Technology

Woody Nero, Naval Research Laboratory

Coventional Fish-Finding SonarCoventional Fish-Finding Sonar

R/V Henlopen

80 m

10 m10 m

Frequency: 38 kHzFrequency: 38 kHzBeamwidth: 6.8Beamwidth: 6.8oo

Lay

er S

tren

gth

(d

B)

Approx. 2 km

0 m

100 m

50 m

Echosounder section through the fishEchosounder section through the fish

-20

-30

-40

-50

-60

-70

-80

Average Ship Velocity: ~3 m/sExample MAE2003 Output Courtesy of NRL

Measuring and Monitoring Fish Populations with Ocean Waveguide Remote Sensing (OAWRS)

Location of 2003 OAWRS Survey: Continental Shelf South of NY

Remote Imaging in the Continental Shelf

The Geoclutter Program

US Research Ship (RV) Oceanus: OAWRS Receiver Ship

RV Endeavor: OAWRS Source Ship

OAWRS 2003 Survey

Fish GroupingsFish Groupings

Moored Vertical Moored Vertical Source ArraySource Array

Towed Receiver Towed Receiver ArrayArray

RV Henlopen:Conventional Fish Finding

Sonar (CFFS) Survey

CFFS TransectCFFS Transect

Local Water DepthLocal Water Depth~80-100m~80-100m

Geometric Spreading: Free space & waveguides

24)(

r

Power

Area

PowerrI

π==

Free Space (CFFS):

Spherical Spreading Loss in Free Space

H

PowerAreaPower

Iπρ

ρ2

)( ==

2-D Waveguide (OAWRS) :

1-D Waveguide:

No Geometric Spreading Loss in a 1-D Waveguide

Cylindrical Spreading Loss in a 2-D Waveguide

A

Constant==AreaPowerI

A

r22

22 4 rA π=

r1 211 4 rA π=

ρ2ρ1

H

AA

HA 22 2πρ=HA 11 2πρ=

Movie Box

Source

Receiver

A small A small fish groupfish group

Continen

tal S

helf E

dge

ConsolidatedConsolidatedShoalShoal

80m70m

100m

120m 800m

Eastings from Source (km)

No

rth

ing

s fr

om

So

urc

e (k

m)

09:32 EDT

Vacuoles within large

shoal

Fish Bridges connecting population

centers

Population Centers

Instantaneous OAWRS Image of Areal Fish Population Density

Instantaneous OAWRS Image of Areal Fish Population Density

Fish Species Found in the Continental Shelf South of NY

Black Sea Bass

Silver Hake (whiting)Atlantic Herring

Spotted HakeRed Hake

Atlantic Mackerel

DogfishScup

Instantaneous Wide-Area Detection and Imaging of Fish SchoolsInstantaneous Wide-Area Detection and Imaging of Fish Schools

May 14: 09:32:25 EDT May 15: 08:49:55 EDT

70m

80m

100m

120m

70m

80m

100m120mb

200m400m

Spatial Frequency fs (1/m)

Spatial Fish Population Density SpectrumS

patia

l Fis

h P

opul

atio

n D

ensi

ty S

pect

rum

(fis

h/m

2 )2

/ (1

/m)

Large Shoal Present

Scattered Fish Groups

Spectral density is proportional to fs -1.5

0 3 6 9 12Eastings from Source (km)

-6

-9

-12

-15

-18

11:59:05 EDT11:59:05 EDT 12:09:55 EDT12:09:55 EDT 12:19:55 EDT12:19:55 EDT 12:29:55 EDT12:29:55 EDT

100m100m 100m100m 100m100m 100m100m

αα

ββγγ

δδ

Echogram corresponding to CFFS line transect (11:54:39-12:39:01 EDT)

αα ββ

δδ

No

rth

ing

s

fro

m S

ou

rce

(k

m)

γγ

A B C D

Spatial and Temporal Correlation: OAWRS vs CFFSSpatial and Temporal Correlation: OAWRS vs CFFS

May 14: Fish Population, Area, and Coherence AreaMay 14: Fish Population, Area, and Coherence Area for various density thresholdsfor various density thresholds

Eastern Daylight Time (Hours)

TotalnA>0.2nA<0.2nA>1nA<1

Consolidated Shoal Largest fraction 2nd largest fragment

-6

-9

-12

-15

-18

0 3 6 9 12

(km

)

Pop

ulat

ion

(Mil

lion

s)A

rea

(km

2 )C

oher

ent

Are

a (k

m2 )

Consolidated Shoal Largest fraction 2nd largest fragment

Time Scales of Total Population Change

Time Lag (min) Frequency (cycles/hr)

Nor

mal

ized

Tem

pora

l F

ish

Den

sity

(cy

les/

hr)

-1

Aut

ocor

rela

tion

TotalnA>0.2nA<0.2nA>1nA<1

Pop

ulat

ion(

Mil

lion

s)

Eastern Daylight Time (Hours)

Relative Speed Between Two Populations Centers

-6

-9

-12

-15

-18

0 3 6 9 12

(km

)

May 14: Time series of Relative Speed

Rel

ativ

e S

peed

(m

/s)

Relative Speed (m/s)

Eastern Daylight Time (hours)

Pro

babi

lity

(km)

This new remote sensing technology

“is like Doppler weather radar for fish”

because it

(1) Instantaneously detects, images and continuously monitors fish population and population density over continental-shelf scales

and so

(2) reveals the detailed behavior of fish schools over wide areas.

It will be used to explore marine biology in the Gulf of Maine in 2006, as part of the Census of Marine Life Program, with support from the Sloan Foundation, the National Oceanographic Partnership Program and ONR.

ConclusionsConclusions

Gulf of Maine: Geography Gulf of Maine: Geography

2000

2001

2002

2003

2004

2005

Atlantic Herring Distribution 2000-2005Atlantic Herring Distribution 2000-2005

Average Atlantic Herring Distribution 1999-2005Average Atlantic Herring Distribution 1999-2005

LONG-RANGE BISTATIC OPSLONG-RANGE BISTATIC OPS

R/V OCEANUS R/V ENDEAVOR115-m to 230-m

70-m to 140-m

37-m to 52-m

XF-4: 7-elementMOD-30: 10-element

Variable

Full aperture: 277-mULF aperture: 189-mLF aperture: 94.5-mMF aperture: 47.25-mHF aperture: 23.625-mTriplet aperture: 15.4-m

24-m to 55-m

Variable

Horizontal Receiving Array

Variable

Variable

Vertical Source Array

Seafloor

TOWED RECEIVER ARRAY MOORED SOURCE ARRAY

MAIN ACOUSTICS EXPERIMENT APRIL-MAY 2003

Loading onto RV Endeavor

OAWRS Vertical Source Array

OAWRS Towed Receiver Array on Spool on RV Oceanus

Expected acoustic intensity level in a fluctuating ocean (Ratilal and Makris, JASA 2005; Chen, Ratilal, Makris JASA 2005)

Frequency: 415 Hz (Low pitch A)

Dis

tanc

e

(km

)

Distance (km)

Fish Inversion: Intermediate Steps

One Way TL from SourcedB

Re 1m One Way TL from ReceiverdB

Re 1mTwo Way TL Convolved with Beam

Pattern of the Array

dB Re 1m

SPL: May 14, 09:33:25 EDTLFM: 390-440 Hz

dB Re 1uPa Scattering Strength Fish Density Distribution Fish/m2

Dis

tanc

e

(km

)

Distance (km)

dB

Coventional Fish-Finding SonarCoventional Fish-Finding Sonar

R/V Henlopen

80 m

10 m10 m

Frequency: 38 kHzFrequency: 38 kHzBeamwidth: 6.8Beamwidth: 6.8oo

Lay

er S

tren

gth

(d

B)

Approx. 2 km

0 m

100 m

50 m

Echosounder section through the fishEchosounder section through the fish

-20

-30

-40

-50

-60

-70

-80

Average Ship Velocity: ~3 m/sExample MAE2003 Output Courtesy of NRL

Fish Species Found in the Continental Shelf South of NY

Black Sea Bass

Silver Hake (whiting)Atlantic Herring

Spotted HakeRed Hake

Atlantic Mackerel

DogfishScup

Movie Box

Source

Receiver

A small A small fish groupfish group

Continen

tal S

helf E

dge

ConsolidatedConsolidatedShoalShoal

80m70m

100m

120m 800m

Eastings from Source (km)

No

rth

ing

s fr

om

So

urc

e (k

m)

09:32 EDT

Vacuoles within large

shoal

Fish Bridges connecting population

centers

Population Centers

Instantaneous OAWRS Image of Areal Fish Population Density

Instantaneous Wide-Area Detection and Imaging of Fish SchoolsInstantaneous Wide-Area Detection and Imaging of Fish Schools

May 14: 09:32:25 EDT May 15: 08:49:55 EDT

70m

80m

100m

120m

70m

80m

100m120mb

200m400m

Spatial Frequency fs (1/m)

Spatial Fish Population Density SpectrumS

patia

l Fis

h P

opul

atio

n D

ensi

ty S

pect

rum

(fis

h/m

2 )2

/ (1

/m)

Large Shoal Present

Scattered Fish Groups

Spectral density is proportional to fs -1.5

0 3 6 9 12Eastings from Source (km)

-6

-9

-12

-15

-18

11:59:05 EDT11:59:05 EDT 12:09:55 EDT12:09:55 EDT 12:19:55 EDT12:19:55 EDT 12:29:55 EDT12:29:55 EDT

100m100m 100m100m 100m100m 100m100m

αα

ββγγ

δδ

Echogram corresponding to CFFS line transect (11:54:39-12:39:01 EDT)

αα ββ

δδ

No

rth

ing

s

fro

m S

ou

rce

(k

m)

γγ

A B C D

Spatial and Temporal Correlation: OAWRS vs CFFSSpatial and Temporal Correlation: OAWRS vs CFFS

May 14: Fish Population, Area, and Coherence AreaMay 14: Fish Population, Area, and Coherence Area for various density thresholdsfor various density thresholds

Eastern Daylight Time (Hours)

TotalnA>0.2nA<0.2nA>1nA<1

Consolidated Shoal Largest fraction 2nd largest fragment

-6

-9

-12

-15

-18

0 3 6 9 12

(km

)

Pop

ulat

ion

(Mil

lion

s)A

rea

(km

2 )C

oher

ent

Are

a (k

m2 )

Consolidated Shoal Largest fraction 2nd largest fragment

Time Scales of Total Population Change

Time Lag (min) Frequency (cycles/hr)

Nor

mal

ized

Tem

pora

l F

ish

Den

sity

(cy

les/

hr)

-1

Aut

ocor

rela

tion

TotalnA>0.2nA<0.2nA>1nA<1

Pop

ulat

ion(

Mil

lion

s)

Eastern Daylight Time (Hours)

Relative Speed Between Two Populations Centers

-6

-9

-12

-15

-18

0 3 6 9 12

(km

)

May 14: Time series of Relative Speed

Rel

ativ

e S

peed

(m

/s)

Relative Speed (m/s)

Eastern Daylight Time (hours)

Pro

babi

lity

(km)

This new remote sensing technology

“is like Doppler weather radar for fish”

because it

(1) Instantaneously detects, images and continuously monitors fish population and population density over continental-shelf scales

and so

(2) reveals the detailed behavior of fish schools over wide areas.

It will be used to explore marine biology in the Gulf of Maine in 2006, as part of the Census of Marine Life Program, with support from the Sloan Foundation, the National Oceanographic Partnership Program and ONR.

ConclusionsConclusions

Gulf of Maine: Geography Gulf of Maine: Geography

2000

2001

2002

2003

2004

2005

Atlantic Herring Distribution 2000-2005Atlantic Herring Distribution 2000-2005

Average Atlantic Herring Distribution 1999-2005Average Atlantic Herring Distribution 1999-2005