The apparent disappearance of Loligo forbesi from the south of its range in the 1990s

Trends in Loligo spp. abundance in the northeast Atlantic and possible environmental influences

C. -. S. Chen, Graham John Pierce, Jianjun Wang, J. -. P. Robin, J. C. Poulard, J. Pereira, A. F. Zuur, Peter Robin Boyle, N. Bailey, D. J. Beare, P. Jereb, S. Ragonese, A. Mannini, L. Orsi-Relini

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Abstract

Since the early 1990s, Loligoforbesi has apparently disappeared from much of the southern part of its former range, with catches off the Iberian Peninsula, for example, declining dramatically during the 1990s. The present paper assembles data from fishery and research cruise databases to examine the evidence for a shift in distribution, examine the relationship between abundance of this species and that of the partially sympatric Loligo vulgaris, and identify possible environmental correlates. Time-series of abundance of L. forbesi and L. vulgaris were assembled using fishery and survey data from Scotland, France, and Portugal. Based on availability of data and timing of the main fishery, data for autumn (October-December) were selected. Nine squid series and two explanatory variables (October sea surface temperature and the winter NAO index) were analysed using dynamic factor analysis (DFA). The optimal DFA model contained two common trends and both of the explanatory variables. The first common trend shows an increase from 1987 to 1999, and a slight decrease after 2000 onwards, and is positively related to L. forbesi abundance in the north of its range (Scotland), while negatively related to squid abundance (both species) in the south of their ranges (France and Portugal). The second trend identifies an increase from 1990 to 1995, followed by a decrease until 2002, and is positively related to the squid (L. forbesi and L. vulgaris) abundance series from French surveys and fisheries. The SST series was significantly related to three squid abundance series: positively with abundance of small L. forbesi in French surveys and negatively with the abundance of small L. forbesi from Scottish surveys and abundance of L. vulgaris in Portuguese surveys. The winter NAO series was significantly related to the abundance of small L. forbesi from Scottish surveys. The increase in SST after 1993 and subsequent high level may thus be associated with the decrease of Loligo abundance in the south area (France and Portugal) and the increase in Loligo abundance in the north area (Scotland). (c) 2006 Elsevier B.V. All rights reserved.

Original languageEnglish
Pages (from-to)44-54
Number of pages10
JournalFisheries Research
Volume78
Issue number1
DOIs
Publication statusPublished - Apr 2006

Keywords

  • Loligo
  • squid fishery
  • abundance
  • common trends
  • dynamic factor analysis
  • North Atlantic Oscillation (NAO)
  • dynamic factor-analysis
  • Scottish Waters
  • English-Channel
  • time-series
  • fished population
  • depletion methods
  • additive-models
  • life-history
  • squid

Cite this

The apparent disappearance of Loligo forbesi from the south of its range in the 1990s : Trends in Loligo spp. abundance in the northeast Atlantic and possible environmental influences. / Chen, C. -. S.; Pierce, Graham John; Wang, Jianjun; Robin, J. -. P.; Poulard, J. C.; Pereira, J.; Zuur, A. F.; Boyle, Peter Robin; Bailey, N.; Beare, D. J.; Jereb, P.; Ragonese, S.; Mannini, A.; Orsi-Relini, L.

In: Fisheries Research, Vol. 78, No. 1, 04.2006, p. 44-54.

Research output: Contribution to journalArticle

Chen, CS, Pierce, GJ, Wang, J, Robin, JP, Poulard, JC, Pereira, J, Zuur, AF, Boyle, PR, Bailey, N, Beare, DJ, Jereb, P, Ragonese, S, Mannini, A & Orsi-Relini, L 2006, 'The apparent disappearance of Loligo forbesi from the south of its range in the 1990s: Trends in Loligo spp. abundance in the northeast Atlantic and possible environmental influences', Fisheries Research, vol. 78, no. 1, pp. 44-54. https://doi.org/10.1016/j.fishres.2005.12.002
Chen, C. -. S. ; Pierce, Graham John ; Wang, Jianjun ; Robin, J. -. P. ; Poulard, J. C. ; Pereira, J. ; Zuur, A. F. ; Boyle, Peter Robin ; Bailey, N. ; Beare, D. J. ; Jereb, P. ; Ragonese, S. ; Mannini, A. ; Orsi-Relini, L. / The apparent disappearance of Loligo forbesi from the south of its range in the 1990s : Trends in Loligo spp. abundance in the northeast Atlantic and possible environmental influences. In: Fisheries Research. 2006 ; Vol. 78, No. 1. pp. 44-54.
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abstract = "Since the early 1990s, Loligoforbesi has apparently disappeared from much of the southern part of its former range, with catches off the Iberian Peninsula, for example, declining dramatically during the 1990s. The present paper assembles data from fishery and research cruise databases to examine the evidence for a shift in distribution, examine the relationship between abundance of this species and that of the partially sympatric Loligo vulgaris, and identify possible environmental correlates. Time-series of abundance of L. forbesi and L. vulgaris were assembled using fishery and survey data from Scotland, France, and Portugal. Based on availability of data and timing of the main fishery, data for autumn (October-December) were selected. Nine squid series and two explanatory variables (October sea surface temperature and the winter NAO index) were analysed using dynamic factor analysis (DFA). The optimal DFA model contained two common trends and both of the explanatory variables. The first common trend shows an increase from 1987 to 1999, and a slight decrease after 2000 onwards, and is positively related to L. forbesi abundance in the north of its range (Scotland), while negatively related to squid abundance (both species) in the south of their ranges (France and Portugal). The second trend identifies an increase from 1990 to 1995, followed by a decrease until 2002, and is positively related to the squid (L. forbesi and L. vulgaris) abundance series from French surveys and fisheries. The SST series was significantly related to three squid abundance series: positively with abundance of small L. forbesi in French surveys and negatively with the abundance of small L. forbesi from Scottish surveys and abundance of L. vulgaris in Portuguese surveys. The winter NAO series was significantly related to the abundance of small L. forbesi from Scottish surveys. The increase in SST after 1993 and subsequent high level may thus be associated with the decrease of Loligo abundance in the south area (France and Portugal) and the increase in Loligo abundance in the north area (Scotland). (c) 2006 Elsevier B.V. All rights reserved.",
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T2 - Trends in Loligo spp. abundance in the northeast Atlantic and possible environmental influences

AU - Chen, C. -. S.

AU - Pierce, Graham John

AU - Wang, Jianjun

AU - Robin, J. -. P.

AU - Poulard, J. C.

AU - Pereira, J.

AU - Zuur, A. F.

AU - Boyle, Peter Robin

AU - Bailey, N.

AU - Beare, D. J.

AU - Jereb, P.

AU - Ragonese, S.

AU - Mannini, A.

AU - Orsi-Relini, L.

PY - 2006/4

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N2 - Since the early 1990s, Loligoforbesi has apparently disappeared from much of the southern part of its former range, with catches off the Iberian Peninsula, for example, declining dramatically during the 1990s. The present paper assembles data from fishery and research cruise databases to examine the evidence for a shift in distribution, examine the relationship between abundance of this species and that of the partially sympatric Loligo vulgaris, and identify possible environmental correlates. Time-series of abundance of L. forbesi and L. vulgaris were assembled using fishery and survey data from Scotland, France, and Portugal. Based on availability of data and timing of the main fishery, data for autumn (October-December) were selected. Nine squid series and two explanatory variables (October sea surface temperature and the winter NAO index) were analysed using dynamic factor analysis (DFA). The optimal DFA model contained two common trends and both of the explanatory variables. The first common trend shows an increase from 1987 to 1999, and a slight decrease after 2000 onwards, and is positively related to L. forbesi abundance in the north of its range (Scotland), while negatively related to squid abundance (both species) in the south of their ranges (France and Portugal). The second trend identifies an increase from 1990 to 1995, followed by a decrease until 2002, and is positively related to the squid (L. forbesi and L. vulgaris) abundance series from French surveys and fisheries. The SST series was significantly related to three squid abundance series: positively with abundance of small L. forbesi in French surveys and negatively with the abundance of small L. forbesi from Scottish surveys and abundance of L. vulgaris in Portuguese surveys. The winter NAO series was significantly related to the abundance of small L. forbesi from Scottish surveys. The increase in SST after 1993 and subsequent high level may thus be associated with the decrease of Loligo abundance in the south area (France and Portugal) and the increase in Loligo abundance in the north area (Scotland). (c) 2006 Elsevier B.V. All rights reserved.

AB - Since the early 1990s, Loligoforbesi has apparently disappeared from much of the southern part of its former range, with catches off the Iberian Peninsula, for example, declining dramatically during the 1990s. The present paper assembles data from fishery and research cruise databases to examine the evidence for a shift in distribution, examine the relationship between abundance of this species and that of the partially sympatric Loligo vulgaris, and identify possible environmental correlates. Time-series of abundance of L. forbesi and L. vulgaris were assembled using fishery and survey data from Scotland, France, and Portugal. Based on availability of data and timing of the main fishery, data for autumn (October-December) were selected. Nine squid series and two explanatory variables (October sea surface temperature and the winter NAO index) were analysed using dynamic factor analysis (DFA). The optimal DFA model contained two common trends and both of the explanatory variables. The first common trend shows an increase from 1987 to 1999, and a slight decrease after 2000 onwards, and is positively related to L. forbesi abundance in the north of its range (Scotland), while negatively related to squid abundance (both species) in the south of their ranges (France and Portugal). The second trend identifies an increase from 1990 to 1995, followed by a decrease until 2002, and is positively related to the squid (L. forbesi and L. vulgaris) abundance series from French surveys and fisheries. The SST series was significantly related to three squid abundance series: positively with abundance of small L. forbesi in French surveys and negatively with the abundance of small L. forbesi from Scottish surveys and abundance of L. vulgaris in Portuguese surveys. The winter NAO series was significantly related to the abundance of small L. forbesi from Scottish surveys. The increase in SST after 1993 and subsequent high level may thus be associated with the decrease of Loligo abundance in the south area (France and Portugal) and the increase in Loligo abundance in the north area (Scotland). (c) 2006 Elsevier B.V. All rights reserved.

KW - Loligo

KW - squid fishery

KW - abundance

KW - common trends

KW - dynamic factor analysis

KW - North Atlantic Oscillation (NAO)

KW - dynamic factor-analysis

KW - Scottish Waters

KW - English-Channel

KW - time-series

KW - fished population

KW - depletion methods

KW - additive-models

KW - life-history

KW - squid

U2 - 10.1016/j.fishres.2005.12.002

DO - 10.1016/j.fishres.2005.12.002

M3 - Article

VL - 78

SP - 44

EP - 54

JO - Fisheries Research

JF - Fisheries Research

SN - 0165-7836

IS - 1

ER -