Updated combined biomass index of abundance of North Atlantic swordfish stock 1963-2015.
Authors
Ortiz, M.; Mejuto-García, J. (Jaime); Hanke, A. (Alex); Ijima, Hirotaka; Walter, J.; Coelho, R. (Rui); Abdel Illah IkkissDate
2017Type
research articleKeywords
SwordfishCatch/effort
Longline
GLM
Biomass index
Swordfish
Catch/effort
Longline
GLM
Biomass index
Abstract
Surplus Production Models of North Atlantic swordfish have been used in addition to age
structured virtual population analyses by ICCAT's SCRS to evaluate the status of the resource
and to provide a basis for management advice. Production models require a standardized index
of relative abundance in terms of biomass. The standardized biomass index of abundance
developed for the 2006, 2008 and 2012 ICCAT SCRS meetings for North Atlantic swordfish was
revised and updated with data through 2015. Generalized Linear Modeling (GLM) procedures
were used to standardize swordfish catch (biomass) and effort (number of hooks) data from the
major longline fleets operating in the North Atlantic; United States, EU-Spain, Canada, Japan,
Morocco and EU-Portugal. As in past analyses, main effects included: year, area, quarter, a
nation-operation variable accounting for gear and operational differences thought to influence
swordfish catchability, and a target variable to account for trips where fishing ... Surplus Production Models of North Atlantic swordfish have been used in addition to age
structured virtual population analyses by ICCAT's SCRS to evaluate the status of the resource
and to provide a basis for management advice. Production models require a standardized index
of relative abundance in terms of biomass. The standardized biomass index of abundance
developed for the 2006, 2008 and 2012 ICCAT SCRS meetings for North Atlantic swordfish was
revised and updated with data through 2015. Generalized Linear Modeling (GLM) procedures
were used to standardize swordfish catch (biomass) and effort (number of hooks) data from the
major longline fleets operating in the North Atlantic; United States, EU-Spain, Canada, Japan,
Morocco and EU-Portugal. As in past analyses, main effects included: year, area, quarter, a
nation-operation variable accounting for gear and operational differences thought to influence
swordfish catchability, and a target variable to account for trips where fishing ...