SAITHE AND HAKE SPATIAL INTERACTIONS IN THE NORTH SEA

SAITHE AND HAKE SPATIAL INTERACTIONSIN THE NORTH SEA

ICES/NAFO Symposium

Xochitl Cormon1,2,C. Loots1, K. Rabhi1, M. Rouquette1, S. Vaz1, Y. Vermard1 and

P. Marchal1

1IFREMER Boulogne-sur-MerFishery Science Departement

2Université Lille 1Sciences and Technology

15-18 October 2013, Saint Andrews, NB, Canada

Introduction Context

The North Sea:

An European areaAn ecosytem changing..

Environmentalfactors1

Human activity

with consequences..on speciesdistribution2

and speciesinteractions3

1ICES, 2008

2Perry et al., 20053Klein et al., 2008

X. CORMON Saithe and hake spatial interactions October 2013 1 / 8


The North Sea:



Human activity



1ICES, 20082Perry et al., 20053Klein et al., 2008



The North Sea:



Human activity



1ICES, 20082Perry et al., 20053Klein et al., 2008


Introduction Species presentation

Two species of interest:

Which species?

Saithe, Pollachius virens Hake, Merluccius merluccius




Which species?


Historical trends of SSB4

2010

600

2000199019801970

500

400

300

200

100

0

SSBS_1000t

Saithe(IIIa, IV and VI)Hake(IIIa, IV, VI, VII and VIIIa,b,d)

4ICES, 2013X. CORMON Saithe and hake spatial interactions October 2013 2 / 8



Which species?


Presence-absence ratio per statistical rectangles of the area of interest over years(Data from DATRAS, 1991-2012, Q1)

0.00

0.25

0.50

0.75

1.00

01

1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012

Saithe

0 00

0.25

0.50

0.75

1.00

1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012Hake


Materials and methods Species presence and overlap

Understand their spatial distribution and overlap

1 Data from DATRAS, 1991-2012, Q12 Presence-absence GLM (binomial, logit)

Response: saithe, hake or overlapDescriptors:

ENV: temperature, bathymetry and sediment type;ORG: saithe, hake, cod groups (G. morhua), Norway pout (T.

esmarkii), herring groups (C. harengus) and blue whiting(M. poutassou) presence-absence4,5;

Selection based on parsimony and sensitivity (true positive rate)calculated on a separate predictive dataset

3 Mapping4 R software

4Bergstad, 19915Dubuit, 1991





Response: saithe, hake or overlap

Descriptors:ENV: temperature, bathymetry and sediment type;ORG: saithe, hake, cod groups (G. morhua), Norway pout (T.

































3 Mapping

4 R software























Results and discussion Models fit

Models fit

Some of the relevant descriptors effectsSaithe Hake Overlap S H O S H O

adjR2 0.45 0.38 0.29

NS NA NATEMP SAITHE NORWAY POUT

NA NADEPTH HAKE HERRING juv

Other descriptorsSediment type is never significant except for fine sand for all models (´);Cod is significant for saithe and overlap models (`) while adults herring is only forhake and overlap ones (`), blue whiting is only significant for hake (`).


Results and discussion Maps from models output

Saithe presence probability evolution since 1991

Probable habitat at first quarter(1991-1996)

0 5 10

5254

5658

60

0.0

0.2

0.4

0.6

0.8

1.0

Changes in presence probabilityover the last 15 years

0 5 10

5254

5658

60

−0.4

−0.2

0.0

0.2

0.4



Hake presence probability evolution since 1991

Probable habitat at first quarter(1991-1996)

0 5 10

5254

5658

60

0.0

0.2

0.4

0.6

0.8

1.0

Changes in presence probabilityover the last 15 years

0 5 10

5254

5658

60

−0.4

−0.2

0.0

0.2

0.4



Overlap evolution since 1991

Probable overlap at first quarter(1991-1996)

0 5 10

5254

5658

60

0.0

0.2

0.4

0.6

0.8

1.0

Changes in overlap probabilityover the last 15 years

0 5 10

5254

5658

60

−0.4

−0.2

0.0

0.2

0.4


Outlooks

Outlooks

1 Input efficient spatial autocorrelation consideration (SAC)

2 Stomach content analysis study (in progress)

3 Combination of modeling and experimental results

4 Enter in a predictive mode

5 Application to management in multispecific and ecosystemic approachcontext


Outlooks

Outlooks







Outlooks

Outlooks







Outlooks

Outlooks







Outlooks

Outlooks







The End

The End...

Thank you for your attention.Any question?


References

References

Bergstad, O. A. (1991). "Distribution and Trophic Ecology of Some Gadoid Fish of theNorwegian Deep .1. Accounts of Individual-Species." Sarsia 75(4): 269-313.Borcard, D., Gillet, F. and P. Legendre (2011)."Eigenvector-Based Spatial variables and SpatialModelling." Numerical Ecology with R: 243-279. Springer, UseR!Dubuit, M. H. (1991). "Food and feeding of saithe (Pollachius virens) off Scotland." FisheriesResearch 12(4): 307-323.ICES (2013). "Saithe in Subareas IV, VI and Division IIIa." Report of the Working Group on theAssessment of Demersal Stocks in the North Sea and Skagerrak (WGNSSK): ICESCM/ACOM:13 : 565-609.ICES (2013). "Hake in Division IIIa, Subareas IV, VI and VII and Divisions VIIIa,b,d (Northernstock)" Report of the Working Group on the Assessment of Southern Shelf Stocks of Hake,Monk and Megrim (WGHMM): ICES CM/ACOM:11 : 34-73.ICES Database of Trawl Surveys (2013). "ICES Database of Trawl Surveys (DATRAS)"Extraction JUNE 2013 of International Bottom Trawl Survey (IBTS). ICES, Copenhagen”Klein, D. R., H. H. Bruun, et al. (2008). "Climate change influences on speciesinterrelationships and distributions in high-Arctic Greenland." Advances in Ecological Research,Vol 40 40: 81-100.Perry, A. L., P. J. Low, et al. (2005). "Climate change and distribution shifts in marine fishes."Science 308(5730): 1912-1915.


Annex Non-spatial or spatial?

Comparison of non-spatial and spatial models

SaitheModel type NbTot NbORG NbENV TPR Dev ě 1% SACENV+ORG 11 6 5 0.84 4 5*** 0.25ENV+ORG+MEM 25 3 3 0.88 7 4*** 0.15

HakeModel type NbTot NbORG NbENV TPR Dev ě 1% SACENV+ORG 13 5 8 0.88 6 9*** 0.35ENV+ORG+MEM 21 1 5 0.90 10 8*** 0.25

OverlapModel type NbTot NbORG NbENV TPR Dev ě 1% SACENV+ORG 10 4 6 0.89 8 5*** 0.30ENV+ORG+MEM 14 0 4 0.93 8 4*** 0.20

Models without SAC consideration are chosen


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SAITHE AND HAKE SPATIAL INTERACTIONS IN THE NORTH SEA