Fisheries and Resources Monitoring System

Jack mackerel - Southeast Pacific
Marine Resource  Fact Sheet
Stock status report 2018
Jack mackerel - Southeast Pacific
Fact Sheet Citation  
Jack mackerel
Owned bySouth Pacific Regional Fisheries Management Organisation (SPRFMO) – More
Monitoring periodThis marine resource is reported in FIRMS from 1970.
Related observationsLocate in inventorydisplay tree map
FAO Names: en - Chilean jack mackerel, fr - Chinchard du Chili, es - Jurel chileno, ru - Ставрида перуанская

Fishery Indicators
Production: Catch
Geographic extent of Jack mackerel - Southeast Pacific
Main Descriptors
Considered a single stock: Yes        Spatial Scale: Regional
Management unit: Yes        Reference year: 2018
Biological State and Trend
State & Trend Descriptors
Exploitation rateF ~ 0.09Moderate fishing mortality
Abundance levelSSB(2018) ~ 4777000 tIntermediate abundance
FAO Categories
Exploitation stateMaximally sustainably fished

The conditions for the jack mackerel stock continue to improve in general. The Scientific Committee discussed the outcomes of the Assessment Workshop held in May 2018, focusing on reviewing new data sources and evaluating the model assumptions, leading to a “full” assessment and concluding with a preferred assessment configuration. This new information reduced previous estimates of recruitment such that the projected stock increase was somewhat moderated. Fishing mortality rates in the past three years decreased and this, along with a modest improvement in recruitment, contributed to an estimated increase in biomass.
Habitat and Biology
Climatic zone: Temperate.   Horizontal distribution: Oceanic.   Vertical distribution: Pelagic.  

Geographical Distribution
Jurisdictional distribution: Straddling between High Seas and EEZ

Water Area Overview
Spatial Scale: Regional

Geo References
Resource Structure
Considered a single stock: Yes

The Chilean jack mackerel (Trachurus murphyi, Nichols 1920) is widespread throughout the South Pacific, along the shelf and oceanic waters adjacent to Ecuador, Peru, and Chile, and across the South Pacific along the Subtropical Convergence Zone in what has been described as the “jack mackerel belt” that goes from the coast of Chile to New Zealand within a 35˚ to 50˚ S variable band across the South Pacific. 
Fishery Indicators
TypeMeasureValueUnitTime period
ProductionCatch 116705tonnes1970
Catch 167631tonnes1971
Catch 111285tonnes1972
Catch 164376tonnes1973
Catch 322723tonnes1974
Catch 299104tonnes1975
Catch 396458tonnes1976
Catch 848071tonnes1977
Catch 1024764tonnes1978
Catch 1301611tonnes1979
Catch 1316363tonnes1980
Catch 1944670tonnes1981
Catch 2371611tonnes1982
Catch 1870262tonnes1983
Catch 2686902tonnes1984
Catch 2370934tonnes1985
Catch 2072848tonnes1986
Catch 2679764tonnes1987
Catch 3245699tonnes1988
Catch 3547077tonnes1989
Catch 3714757tonnes1990
Catch 3777618tonnes1991
Catch 3361674tonnes1992
Catch 3369598tonnes1993
Catch 4274793tonnes1994
Catch 4955186tonnes1995
Catch 4378844tonnes1996
Catch 3597117tonnes1997
Catch 2025758tonnes1998
Catch 1423447tonnes1999
Catch 1540318tonnes2000
Catch 2527725tonnes2001
Catch 1750077tonnes2002
Catch 1797229tonnes2003
Catch 1934411tonnes2004
Catch 1754673tonnes2005
Catch 2020136tonnes2006
Catch 1996975tonnes2007
Catch 1472631tonnes2008
Catch 1283473tonnes2009
Catch 726573tonnes2010
Catch 634800tonnes2011
Catch 454746tonnes2012
Catch 353120tonnes2013
Catch 410703tonnes2014
Catch 394332tonnes2015
Catch 389067tonnes2016
Catch 404609tonnes2017
Catch 472966tonnes2018
Level of uncertainty: Low

A statistical catch-at-age model is used to evaluate the jack mackerel stocks. The JJM (“Joint Jack Mackerel Model”) is implemented in ADMB and considers different types of information, which corresponds to the available data of the jack mackerel fishery in the South Pacific area from 1970 to 2018. The operational population dynamics model is defined by the standard catch equation with various modifications such as those described by Fournier and Archibald (1982), Hilborn and Walters (1992) and Schnute and Richards (1995). This model was adopted as assessment method in 2010 after several technical meetings. 

Catch-at-Age, Catch-at-Length, Landings by Fleet (5), CPUE, Acoustic, DEPM 
Assessment Model
Type:  Age-structured
Joint Jack Mackerel Model (JJM)

The JJM model is an explicit age-structured model that uses a forward projection approach and maximum likelihood estimation to solve for model parameters. The model can be considered to consist of several components, (i) the dynamics of the stock; (ii) the fishery dynamics; (iii) observation models for the data; and (iv) the procedure used for parameter estimation (including uncertainties). Stock dynamics: recruitment is considered to occur in January while the spawning season is considered as an instantaneous process at mid-November. The population’s age composition considers individuals from 1 to 12+ years old for the single stock hypothesis as well as for the southern stock in the two-stock hypothesis, while for the northern stock 1 to 8+ years old are considered.
Overall Assessment Results

New data and indicators on the status of the jack mackerel stock suggest that conditions evaluated in detail from the last benchmark assessment (completed in 2018) are relatively unchanged. The population trend is estimated to be increasing. The indications of stock improvement (higher abundance observed in the acoustic survey in the northern part of Chile, better catch rates apparent in some fisheries, and increase in average age in the Chilean fisheries) drive the increase. Near term spawning biomass is expected to increase from the 2018 estimate of 4.8 million t to 5.6 million t in 2019 (with approximate 90% confidence bounds of 4.5 – 7.0 million t). 
Scientific Advice

Recent increases in the theoretical BMSY values (estimated in the model; likely due to changes in selectivity of all fisheries combined) would imply a ratio of about 70% of BMSY. This indicates that under the rebuilding plan, the status quo fishing mortality would apply resulting in catch levels at or below 591 kt.
Management unit: Yes

At least five units of T. murphyi associated to distinct fisheries are identified in the Southeast Pacific: the Ecuadorian fishery, which is managed as part of a more general pelagic fishery within the Ecuadorian EEZ; the Peruvian fishery, which is managed as part of a jack mackerel, mackerel and sardine fishery directed exclusively for direct human consumption taking place almost entirely within the Peruvian EEZ; the northern and the central-southern Chilean fisheries which are managed as separate management units, with the northern fishery being mostly within Chilean EEZ and the central-southern Chilean fishery which straddles the Chilean EEZ and the adjacent high sea; and, the purely high sea fishery which is a multinational fishery being managed entirely within the context of the SPRFMO (it should be noted that Chile has given its express consent for the SPRFMO jack mackerel CMM to be also applied inside its EEZ).
Source of information
SPRFMO. 2018. Report of the sixth meeting of the Scientific Committee, Puerto Varas, Chile, 9-14 September 2018.  Click to open
SPRFMO. 2018. SC6-JM01, Trachurus murphyi catch history. Chile, 9-14 September 2018.  Click to open
SPRFMO. 2014. Information describing Chilean jack mackerel (Trachurus murphyi) fisheries relating to the South Pacific Regional Fishery Management Organisation.  Click to open
All references to figures, tables and bibliography in the text are found within the source of information.
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