Whale gates: the importance of permanent submarine observatories for monitoring sperm whale population

structure and trends.

Francesca Zardin, Gianni Pavan, Enrico Pirotta, Francesco Caruso, and Giorgio Riccobene

PhD candidate SD-TAB School University of Milano, ItalyCIBRA -University of Pavia

1th International Workshop Ecology, Behaviour and Conservation of the Mediterranean Sperm Whale – Ischia 17-18 November 2011

©Tethys Research Institute photo by F. Zardin

Team work is fundamental!

My co-authors Gianni Pavan, Enrico Pirotta, Francesco Caruso, and Giorgio Riccobene

CIBRA Team, especially Gianni Pavan, and my headphones colleagues Eugenio Internullo and Gabriella La Manna

NEMO-OvDE for the opportunity and the amazing data

Enrico Pirotta for the strong statistic support, University of Aberdeen

Dr. Francesco Ficetola for the GAMs lessons, University of Milano Bicocca

Dr. Jean-Noel Druon (JRC), for the SST and CHL data

Prof. Marco Ferraguti, Animal Biology department UNIMI

Banca Dati Spiaggiamenti Cetacei, with Elisabetta Bernuzzi and Michela Podestà

Tethys Research Institute for the kind permission to use the pictures and for the constant support

The Sicilian sperm whales always really cooperative!

Istituto Nazionale di Fisica Nucleare-Laboratori Nazionali del Sud

NEMO

Km3 telescopeCerenkov radiation methodology

100 Km off Capo Passero3500 m depth on the sea bed

Idial site features120 towers 1km heigh

10.000 light sensors PMT

Riccobene, 2009

NEMO-OvDE

Phase-1: Ocean Noise Detection Experiment

To test a new methodology based on water ionization acoustic detection caused by muons

To measure the underwater back ground noise

To test experimental equipments

January 2005 -December 2006

LNS Test Site Laboratoryat the port of Catania

LNS-INFN Catania

Internet Radio Link

Test Site South

5 km20 km

NEMO-OvDE

Hydrophone features:- Wide band (30-40 kHz)- Sensitivity: 177 dB re 1 V/μPa- Board AD 24 bit- Sampling rate: 96 kHz- Detection range 15-20 km

Lat: 37° 32.681’Long: 015° 23.773’

Why this is a good place to start a research about Sperm Whales

The western Ionian Sea

Between April-May and October-November presence peaks of

anchovies1 occur,Engraulis encrasicolus, bound to

primary production growth

1- Amore C. et al., 1982

Upwelling south of the Strait

Colder water Levantine and superficial exchange

Sperm whale presence in the Ionian Sea

Strandings2 in the Ionian sea:

11 animals of 152 along the Italian coasts

(1986-2011)

1601-1947 in Italy1:

89 animals stranded/captured

54 in around Sicily waters

Large clusters of 30 individuals

1- Bolognari, 1949 2- Italian Cetacean Strandings Network

Recent surveys

1- Lewis. et al., 20062- Notarbartolo et al., 2006

2003 IFAW1

visual + acoustic survey

3843 km16 individuals detected

N= 62D = 0.23×10 -3

2005-06 Tethys2

Strait of Messina

2300 km2

150 sightings

13.8 % Pm

WE FOUND WHALES

SEARCHING FOR STARS

Data aquirement:- 24 samples/die- 1 sample/h- Each sample: 5 minutes

Audio analisys software: - SeaPro ultra 2.0 g

3 Samplers: - 1 semester each

3.5 TB of data

NEMO-OvDE

Days with samples

Samplesnumber

Analized hours

2005 231 5 147 428 h 55’2006 83 2 212 184 h 20’Total 314 7 359 613 h 15’

Some of the sound cathegories

Presence

Years Samples # At least 1 animal

2005 5 147 1 186

2006 2 212 506

Total 7 359 1 692

GLMsGAMsGEEs

R software package mgcv

Sperm whales are not so rare as it was

believed

Years Samples # At least 1 animal

Positive contacts %

2005 5 147 1 186 23 %

2006 2 212 506 23 %

Total 7 359 1 692 23 %

Seasonal distribution

During spring the presence

is above expected

14,04%

41,47%

23,44%

16,00%

0,00%

10,00%

20,00%

30,00%

40,00%

50,00%

winter spring summer autumn

Seasonal presence distribution 2005Chi squared test

23 = 191,2; P < 0,0001

14,04%

41,47%

23,44%

16,00%

0,00%

10,00%

20,00%

30,00%

40,00%

50,00%

winter spring summer autumn

Seasonal presence distribution 2005

Presence

We tested GEEGLM for

Indipendence

Autocorrelation AR

Model Selection procedure using QIC

Day of the year and

Hour of the day

significantly explain the variability

p < 0.001

Presence Day of the year

GAM- Examined factors: day of the year, year, sampler; quasi-binomial error distribution.Positive samples frequency is significantly different between:• the 2 years• the samplers• The days of the year

50 100 150 200 250 300 350

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

N

s(N

,8.3

5)

Cont

act f

requ

ency

April-May October

df F p-valueYEAR 1 6.283 0.0127Factor (sampler) 1 13.074 3.49e-06

Approximate significance of smooth terms:

edf Est.rank F p-values(N) 8.241 9.000 3.541 0.000333

Presence peaks in Spring

and Autumn

Presence Hour of the day

GEEGLM

Hour of the day

2-3 pm

A daily pattern in sperm whale

sound production is revealed

Group size

² = > = <

Group size 2005

50%

28%

10%12%

1 Pm 2 Pm 3 Pm >3 Pm

Group size 2006

50%

38%

8% 4%

1 Pm 2 Pm 3 Pm >3 Pm

samples 1 Pm 2 Pm 3 Pm >3 Pm presence

2005 594 327 123 142 1 186

2006 252 193 40 21 506

The group size varies between

the 2 years

Group size 2005

50%

28%

10%12%

1 Pm 2 Pm 3 Pm >3 Pm

Group size 2006

50%

38%

8% 4%

1 Pm 2 Pm 3 Pm >3 Pm

Group size

We tested GEEGLM for

Indipendence

Autocorrelation AR

Model Selection procedure using QIC

Day of the year and

Hour of the day

significantly explain the variability

p < 0.001

Group size

GAM- Examined factors: day of the year, year, sampler and presence of at least 1 individual; Poisson error distribution.The number of animals is not significantly different between:• the two years• the samplers

50 100 150 200 250 300 350

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

N

s(N

,6.7

4)Nu

mbe

r of a

nim

als

April-May November

df Chi.sq p-valuep_pres 1 285.487 <2e-16factor(sampler) 1 11.641 0.200YEAR 1 0.032 0.859

Approximate significance of smooth terms:

Edf Est.rank Chi.sq p-values(N) 6.739 9.000 19.01 0.0251

They move in groups

CHL + Lunar phase

Lunar cycle....What a disappointment!

CHLWorks only on a small scale

But it’s not a truecorrelation

Presence- AbsenceAboundance

Codas

SST

Sea Surface TemperatureMean

Standard DeviationMax Min

3 different scale radius20 km80 Km

260 km

presence/absenceaboundance

Year Day of the year

SST

GAMsMean SST is strongly correlated

with presence-absence

Year and Day of the yeardo not affectthe relation

Some like it ......cold

Sperm whales like cold water1, 2

as their preys

1- Jaquet et al., 19962- Pirotta et al., 2011

They use the area when it’s favourable i.e. cold

and maybe while there, some of them cross the Strait....

Sci-fi HypotesysApril May they arrive in the area and when they leave they go to the cold Ligurian Sea

Sci-fi HypotesysNovember they come back

Whale gates or what we are doind now

Measuring IPI manually ( cepstrum)to determine lenght, age, sex

P2-P1 (ms)

Tota

l Len

gth

(m)

Kloeti Master thesys

Whale gates or what we are doind now

Tracking the individuals in real timeF. Bénard, H. Glotin and P. Giraudet

UMR CNRS LSIS – Univ. du Sud Toulon Var

Dept

h (m

)

Time (s)

LNS Test Site Laboratoryat the port of Catania

LNS-INFN Catania

Internet Radio Link

Test Site South

5 km20 km

Test Site North

5 km

INFN, INGV, Tecnomare, CSIC, CIBRA, dBscale, Uni Lisboa, Uni Catalunya, Uni Bremen, Uni Berlin

NEMO JB

BioacousticsOcean MonitoringGeohazards

The Next Steps: LIDO a Demonstration Mission of ESONET

Why is it NEMO – OvDE so special ?

Strategic geographic position

Excellent depth to record sperm whales

Excellent recording equipment

Noise monitoring

Long term real time data good for population studies and trends

Impressive amount of data

Behavioural studies (Codas)

Thank you for your attention