Malta T. a, Santos A. M. a, Santos P. b and Silva A. a IPMA Instituto Português do Mar e da Atmosfera

Transcription

1 Long term variations in the population dynamics of Iberian sardine (Sardina pilchardus) and its relation to environmental conditions and exploitation history Malta T. a, Santos A. M. a, Santos P. b and Silva A. a 2014 a IPMA Instituto Português do Mar e da Atmosfera b FCUP Faculdade de Ciências da Universidade do Porto This study was supported by project CERTIFICA (PROMAR)

2 Study what? Why? Where? ICES Advice, 2014 Map downloaded from: (September, 2014) Study objectives: Create a longerrecruitment data series Model the environmental effectson the recruitment variation Compare the fisheries history with the recruitment index

3 Study what? Why? Where? ICES Advice, 2014 Map downloaded from: (September, 2014) Study objectives: Create a longerrecruitment data series Model the environmental effectson the recruitment variation Compare the fisheries history with the recruitment index

4 Study what? Why? Where? ICES Advice, 2014 Map downloaded from: (September, 2014) Study objectives: Create a longerrecruitment data series Model the environmental effectson the recruitment variation Compare the fisheries history with the recruitment index

5 Material and Methods Data Methods Fisheries data ( ) Monthly sardine landings Length and weight distribution samples Environmental data ( ) Upwelling Index Sea Surface Temperatures North Atlantic Oscillation Index East Atlantic Pattern Index AtlanticMultidecadal Oscillation Index Development of Historical Recruitment Index (HRI) Estimates of number of recruits per kg landed HRIvsEnvironmental variables Generalized Additive Models Sardine fisheries historical compilation Published papers, official reports and grey literature

6 Material and Methods Data Methods Fisheries data ( ) Monthly sardine landings Length and weight distribution samples Environmental data ( ) Upwelling Index Sea Surface Temperatures North Atlantic Oscillation Index East Atlantic Pattern Index AtlanticMultidecadal Oscillation Index Development of Historical Recruitment Index (HRI) Estimates of number of recruits per kg landed HRIvsEnvironmental variables Generalized Additive Models Sardine fisheries historical compilation Published papers, official reports and grey literature

7 HRI

8 HRI

9 HRI vs environmental factors Initial Model HRI~ s(naow) + s(naos) + s(sstw) + s(ssts) + s(eaw) + s(eas) + s(aflo.w) + s(aflo.s) + s(amo.annual) Final Model HRI~ s(naos) + s(amo.annual) + SSTs + aflo.w AMO.anual (p=0.0004); NAOs (p=0.002); SSTs (p=0.003) & aflo.w (p=0.01) Deviance explained = 46.2%

10 HRI vs environmental factors Initial Model HRI~ s(naow) + s(naos) + s(sstw) + s(ssts) + s(eaw) + s(eas) + s(aflo.w) + s(aflo.s) + s(amo.annual) Final Model HRI~ s(naos) + s(amo.annual) + SSTs + aflo.w AMO.anual (p=0.0004); NAOs (p=0.002); SSTs (p=0.003) & aflo.w (p=0.01) Deviance explained = 46.2%

11 HRI vs environmental factors

12 HRI vs environmental factors

13 HRI vs environmental factors

14 HRI vs environmental factors

15 HRI vs environmental factors

16 HRI vs environmental factors

17 HRI vs environmental factors

18 HRI vs environmental factors

19 HRI vs environmental factors

20 HRI vs environmental factors

21 Estimated HRI ESTIMATED HRI HRI

22 Estimated HRI ESTIMATED HRI HRI

23 Estimated HRI ESTIMATED HRI HRI

24 Explotation history vs HRI World War II Events Socio-economic Increased search and Difficulty to Crisis in the canning Gradual recovery of the consumption, access raw Crisis canning sector, increase of sector, high operating canning industry, increase impulse to the material for labour costs costs, market saturation in exports canning industry canning Technological Expansion of modern purse seine, diesel propulsion Introduction of synthetic fibers, echosounder, power blocks Decrease in effort: no. vessels Gradual improvement of fishing power and efficiency due to upgrade of and fishing engines, navigation systems and echolocation equipement days/year halved Gen. reg. Additional regulations: Long-term Fisheries conservation of annual quotas (2000- management plan: "General Regulation of the sardine fishery in the Portuguese coast" (1903) and addendum: fish. resources: 2004), effort limitations, annual quotas, management areas, periods, gear specifications and effort for sardine fisheries. net/ mesh size, seasonal closure in the effort limitation, areas, MLS north seasonal closure Half-decades LANDINGS VESSELS HRI

25 Explotation history vs HRI World War II Events Socio-economic Increased search and Difficulty to Crisis in the canning Gradual recovery of the consumption, access raw Crisis canning sector, increase of sector, high operating canning industry, increase impulse to the material for labour costs costs, market saturation in exports canning industry canning Technological Expansion of modern purse seine, diesel propulsion Introduction of synthetic fibers, echosounder, power blocks Decrease in effort: no. vessels Gradual improvement of fishing power and efficiency due to upgrade of and fishing engines, navigation systems and echolocation equipement days/year halved Gen. reg. Additional regulations: Long-term Fisheries conservation of annual quotas (2000- management plan: "General Regulation of the sardine fishery in the Portuguese coast" (1903) and addendum: fish. resources: 2004), effort limitations, annual quotas, management areas, periods, gear specifications and effort for sardine fisheries. net/ mesh size, seasonal closure in the effort limitation, areas, MLS north seasonal closure Half-decades LANDINGS VESSELS HRI

26 Explotation history vs HRI World War II Events Socio-economic Increased search and Difficulty to Crisis in the canning Gradual recovery of the consumption, access raw Crisis canning sector, increase of sector, high operating canning industry, increase impulse to the material for labour costs costs, market saturation in exports canning industry canning Technological Expansion of modern purse seine, diesel propulsion Introduction of synthetic fibers, echosounder, power blocks Decrease in effort: no. vessels Gradual improvement of fishing power and efficiency due to upgrade of and fishing engines, navigation systems and echolocation equipement days/year halved Gen. reg. Additional regulations: Long-term Fisheries conservation of annual quotas (2000- management plan: "General Regulation of the sardine fishery in the Portuguese coast" (1903) and addendum: fish. resources: 2004), effort limitations, annual quotas, management areas, periods, gear specifications and effort for sardine fisheries. net/ mesh size, seasonal closure in the effort limitation, areas, MLS north seasonal closure Half-decades LANDINGS VESSELS HRI

27 Explotation history vs HRI World War II Events Socio-economic Increased search and Difficulty to Crisis in the canning Gradual recovery of the consumption, access raw Crisis canning sector, increase of sector, high operating canning industry, increase impulse to the material for labour costs costs, market saturation in exports canning industry canning Technological Expansion of modern purse seine, diesel propulsion Introduction of synthetic fibers, echosounder, power blocks Decrease in effort: no. vessels Gradual improvement of fishing power and efficiency due to upgrade of and fishing engines, navigation systems and echolocation equipement days/year halved Gen. reg. Additional regulations: Long-term Fisheries conservation of annual quotas (2000- management plan: "General Regulation of the sardine fishery in the Portuguese coast" (1903) and addendum: fish. resources: 2004), effort limitations, annual quotas, management areas, periods, gear specifications and effort for sardine fisheries. net/ mesh size, seasonal closure in the effort limitation, areas, MLS north seasonal closure Half-decades LANDINGS VESSELS HRI

28 Explotation history vs HRI World War II Events Socio-economic Increased search and Difficulty to Crisis in the canning Gradual recovery of the consumption, access raw Crisis canning sector, increase of sector, high operating canning industry, increase impulse to the material for labour costs costs, market saturation in exports canning industry canning Technological Expansion of modern purse seine, diesel propulsion Introduction of synthetic fibers, echosounder, power blocks Decrease in effort: no. vessels Gradual improvement of fishing power and efficiency due to upgrade of and fishing engines, navigation systems and echolocation equipement days/year halved Gen. reg. Additional regulations: Long-term Fisheries conservation of annual quotas (2000- management plan: "General Regulation of the sardine fishery in the Portuguese coast" (1903) and addendum: fish. resources: 2004), effort limitations, annual quotas, management areas, periods, gear specifications and effort for sardine fisheries. net/ mesh size, seasonal closure in the effort limitation, areas, MLS north seasonal closure Half-decades LANDINGS VESSELS HRI

29 Summary & Conclusions The Historical Recruitment Index proved to be a good indicator of recruitment for the West Portuguese coast; The final model with Annual AMO, summer NAO, summer SST and winter upwelling as covariables, explained 46% of the recruitment variation; Both recruitment and fisheries historical events appear to influence the Portuguese sardine total landings.

30 Summary & Conclusions The Historical Recruitment Index proved to be a good indicator of recruitment for the West Portuguese coast; The final model with Annual AMO, summer NAO, summer SST and winter upwelling as covariables, explained 46% of the recruitment variation; Both recruitment and fisheries historical events appear to influence the Portuguese sardine total landings.