Population distribution and biomass variability of sardine and anchovy in the Canary current system as simulated by an end-to-end coupled model

Sánchez-Garrido, José Carlos; Werner, Francisco; Ramos González, Antonio; Fiechter, Jerome; Curchitser, Enrique; García-Lafuente, Jesús; Arístegui, Javier; Hernández León, Santiago; Rodríguez Santana, Angel

Abstract

Small pelagic fishes as sardine and anchovy account for as much as 20-25% of the world fisheries catch. They are particularly abundant in the four major eastern boundary upwelling ecosystems, where high levels of biological productivity are sustained by the supply of nutrient-rich water from beneath the photic zone. An intrinsic and puzzling feature of small pelagic fish is the large fluctuations of their population, typically occurring at decadal scales. The causes for such fluctuations have been extensively analyzed and discussed in the literature, yet our understanding of the mechanism involved is very limited. End-to-end models are emerging tools useful to test hypothesis for such fish population variability or to gain new insights into the problem. This comprehensive and complex model approach is now becoming possible largely thanks to the present-day computer power. This contribution focuses on the population dynamics of sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) in the Canary Current Upwelling Ecosystem. We describe and present the results of an end-to-end coupled model simulation including these two small pelagic species. The end-to-end application includes three model components: the ROMS circulation sub-model, the lower trophic ecosystem sub-model NEMURO, and a recently developed individual-based model for the fish (Rose et al. 2015; Fiechter et al. 2015). The computational grid for the three models covers NW Africa and the Western Iberian Peninsula at a spatial resolution of 12 km. This resolution is sufficient for certain eddy variability to occur in ROMS. Different biological traits were prescribed for anchovy and sardine: temperature optimum, diet preferences, and the onset and duration of the spawning season, among others. A hind-cast simulation of the period 1958-2007 was carried out. Model results reveal a fairly different behavior of sardine and anchovy. Anchovies gather off the northern part of Morocco and the Gulf of Cadiz, whereas sardines appear more scattered across the domain, further offshore, and further south, where upwelling favorable conditions take place year round. Both species exhibit decadal-scale fluctuations in both the location of the center of mass of the population and their biomass abundance; the latter being reasonably correlated with historical landing records.

Population distribution and biomass variability of sardine and anchovy in the Canary current system as simulated by an end-to-end coupled model

Author: Sánchez-Garrido, José Carlos,Werner, Francisco,Ramos González, Antonio,Fiechter, Jerome,Curchitser, Enrique,García-Lafuente, Jesús,Arístegui, Javier,Hernández León, Santiago,Rodríguez Santana, Angel

Publisher: IUGG Joint Assembly 2017

Year: 2017

Source: https://riuma.uma.es/xmlui/bitstream/10630/14433/1/Joint%20Assembly%202017%20Abstract%20960_JCSG_et_al.pdf

J o i n A s s e m b l y 2 0 1 7 , A b s a c B o o k P a g e | 3 3 7
POPULATION DISTRIBUTION AND BIOMASS VARIABILITY OF SARDINE AND
ANCHOVY IN THE CANARY CURRENT SYSTEM AS SIMULATED BY AN END-
TO-END CUOPLED MODEL
Abs ac ID : 960
Con lic Decla a ion : None
Con en Mo i a ion : None
Addi ional In o ma ion : None
D . José Ca los Sánchez Ga ido ,jcsanc[email p o ec ed]a.es ,(Pos doc esea che ) ,Spain ,Malaga
,No P esen ing1
D . F ancisco We ne ,cisco.we ne @noaa.go ,(None) ,Uni ed S a es , ,No P esen ing2
D . An onio J. Ramos González ,an onio. [email protected] ,(None) ,Spain , ,No P esen ing3
D . Je ome Fiech e , iech e @ucsc.edu ,(None) ,Uni ed S a es , ,No P esen ing4
D . Cu chi se En ique ,cu chi se @gmail.com ,(None) ,Uni ed S a es , ,No P esen ing5
D . Jesús Ga cía La uen e ,gla ue[email p o ec ed]a.es ,(None) ,Spain , ,No P esen ing1
D . Ja ie A ís egui ,ja ie .a is [email protected] ,(None) ,Spain , ,No P esen ing7
D . San iago He nández León ,she [email protected] ,(None) ,Spain , ,No P esen ing8
D . Angel Rod íguez San ana ,angel.san [email protected] ,(None) ,Spain , ,No P esen ing8
1 - Uni e si y o Malaga 2 - NOAA 3 - Uni e sidad del Las Palmas de G an Cana ias 4 - Uni e si y o
Cali o nia San a C uz 5 - Ru ge s Uni e si y 6 - Uni e si y o Malaga 7 - Uni e sidad de las Palmas de
G an Cana ias 8 - Uni e sidad de Las Palmas de G an Cana ias 9 - Uni e sidad de Las Palmas de
G an Cana ias
Small pelagic ishes as sa dine and ancho y accoun o as much as 20-25% o he wo ld ishe ies
ca ch. They a e pa icula ly abundan in he ou majo eas e n bounda y upwelling ecosys ems,
whe e high le els o biological p oduc i i y a e sus ained by he supply o nu ien - ich wa e om
benea h he pho ic zone. An in insic and puzzling ea u e o small pelagic ish is he la ge luc ua ions
o hei popula ion, ypically occu ing a decadal scales. The causes o such luc ua ions ha e been
ex ensi ely analyzed and discussed in he li e a u e, ye ou unde s anding o he mechanism
in ol ed is e y limi ed. End- o-end models a e eme ging ools use ul o es hypo hesis o such ish
popula ion a iabili y o o gain new insigh s in o he p oblem. This comp ehensi e and complex
model app oach is now becoming possible la gely hanks o he p esen -day compu e powe .
This con ibu ion ocuses on he popula ion dynamics o sa dine (Sa dina pilcha dus) and ancho y
(Eng aulis enc asicolus) in he Cana y Cu en Upwelling Ecosys em. We desc ibe and p esen he
esul s o an end- o-end coupled model simula ion including hese wo small pelagic species. The
end- o-end applica ion includes h ee model componen s: he ROMS ci cula ion sub-model, he lowe
J o i n A s s e m b l y 2 0 1 7 , A b s a c B o o k P a g e | 3 3 8
ophic ecosys em sub-model NEMURO, and a ecen ly de eloped indi idual-based model o he ish
(Rose e al. 2015; Fiech e e al. 2015). The compu a ional g id o he h ee models co e s NW A ica
and he Wes e n Ibe ian Peninsula a a spa ial esolu ion o 12 km. This esolu ion is su icien o
ce ain eddy a iabili y o occu in ROMS. Di e en biological ai s we e p esc ibed o ancho y and
sa dine: empe a u e op imum, die p e e ences, and he onse and du a ion o he spawning season,
among o he s. A hind-cas simula ion o he pe iod 1958-2007 was ca ied ou .
Model esul s e eal a ai ly di e en beha io o sa dine and ancho y. Ancho ies ga he o he
no he n pa o Mo occo and he Gul o Cadiz, whe eas sa dines appea mo e sca e ed ac oss he
domain, u he o sho e, and u he sou h, whe e upwelling a o able condi ions ake place yea
ound. Bo h species exhibi decadal-scale luc ua ions in bo h he loca ion o he cen e o mass o he
popula ion and hei biomass abundance; he la e being easonably co ela ed wi h his o ical landing
eco ds.